Taxonomic keys to the species listed in Rio Mayo plants

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Authors Soares, José de Ribamar Pinto, 1940-

Publisher The University of Arizona.

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Link to Item http://hdl.handle.net/10150/554577 TAXONOMIC KEYS TO THE SPECIES LISTED

IN RIO MAYO PLANTS

by

Jose de Ribamar Pinto Soares

A Thesis Submitted to the Faculty of the

DEPARTMENT OF BIOLOGICAL SCIENCES

In Partial Fulfillment of the Requirements For the Degree of

MASTER OF SCIENCE WITH A MAJOR IN BOTANY

In the Graduate College

THE UNIVERSITY OF ARIZONA

1 9 7 3 STATEMENT 'EY AUTHOR

This thesis has been submitted in partial fulfillment of re­ quirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library.

Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judg­ ment the proposed use of the material is in the interests of scholar­ ship. In all other instances, however, permission must be obtained from the author.

SIGNED

APPROVAL BY THESIS DIRECTOR

This thesis has been approved on the date shown below:

/ f ^ 7 3> CHARLES tD'MASON, Jr J Date Professor of Biological Saiences ACKNOWLEDGMENTS

The author wishes to express his gratitude to D r • Charles T »

Mason, Jr., for his time, thoughtful advice, and expert guidance throughout the graduate program.

In addition, acknowledgment is given to the other members of his thesis committee, Drs. James W. O'Leary and Willard Van Asdall, who critically reviewed this paper and offered helpful suggestions.

The author also thanks the sponsors who made the studies at The

University of Arizona possible, such as the United States Agency for

International Development (U.SoA.IoD.) and Universidade Federal do

Ceara (U.F.C)/ University of Arizona (U.A«) Contracte

The author's appreciation is also extended to Dr. W. G. Matlock,

Campus Coordinator-Brazil Program and to his secretary Mrs. Evelyn

Jorgensen, as well as his colleagues at the Departamento de Biologia do

Centro de Ciencias da Universidade Federal do Ceara, Brazil, for their understanding and cooperation.

Finally, the author owes a debt of gratitude to his wife,

Aleuda, and children, Aleksey and Liana, who graciously relinquished

some of the time they would have preferred to have spent with their husband and father. TABLE Of CONTENTS

Page

ABSTRACT v

INTRODUCTION ...... 1

PROCEDURE . , , . . , . « . .. 3

KEY TO THE DIVISIONS « . . « , . , , , . « . . .• , 5

I . PTERIDOPHYTA ...... ' ^ . . , , , 6

Key to the Families of Pterldophyta < «»,*<«,.«.. 6

II. SPERMATOPHYTA...... 15

Key to the Classes of Spermatophyta« ...... 15 Class I. GYMNOSPEREAE ...... 16 Key to the Families of Gymnospermae ...... 16 Class II. ANGIOSPERMAE...... 18 Key to the Sub-classes of Anglospermae...... 18 Sub-class I. MONOCOTYLEDONEAE ...... 19 Key to the Families of Monocottyledoneae ...... 19 Sub-class II. DICOTYLEDONEAE...... 55 Key to the Series of Dicotyledoneae ...... 55

APPENDIX: NOMENCLATURE CHANGES. . , . . . . » ...... 260

LIST OF REFERENCES ...... 274

iv ABSTRACT

Rio Mayo Valley in Sonora, Mexico, is an area highly convenient for biological studies. A Sub-tropical zone between the Lower Sonoran and Upper Sonoran life zones is an important feature of this area»

Plant collections in the valley have been made by many ex­ plorers. The most faithful record is the Gentry collection representing about 3200 specimens. His publication, Rio Mayo Plants, also, is the first one regarding geography, vegetation, plant census, succession and plant uses.

This study was undertaken to provide a means for the identifi­ cation of the species cited by Gentry in his work through the Rio Mayo

Basin. Keys are given to separate all taxa: 131 families, 532 genera,

1245 species, and 94 subspecific categories.

An appendix is included to bring up-to-date the nomenclature for the taxa.

v INTRODUCTION

According to Gentry (31), the Rio Mayo with a drainage basin of about 17,648*26 square kilometers (6814 square miles) is one of the most important rivers in the State of Sonora, Mexico* Originating in the

Sierra Madre of western Chihuahua, it discharges into the Gulf of Cali­ fornia 64 kilometers (40 miles) north of the boundary between Sonora and Sinaloa*

The environmental combinations of climate, soil, drainage pat­ terns, geological history, and many other factors have markedly influ­ enced the vegetation in the valley, where Gentry (31) reports the most conspicuous natural feature is the presence of a subtropical zone as a northern extension of the tropics, between the Lower Sonoran and the

Upper Sonoran life zones* An excellent description of the vegetation of the drainage area, of which the Mayo Valley is included, is given by

Gentry (31), and provides good information about the plant census, succession, and use as well as the list of species that compose the flora *

Since the area is suitable for biological studies plant collec- / tions have been made as early as the Carl Lumholtz Expedition of 1890, when Co V. Hartman and F* E* Lloyd went through the Sierra Madre from

Bavispe Valley, in Sonora, to Casas Grandes, Chihuahua * Subsequent field work was undertaken by other explorers; however a catalogue of their collections and observations on the character or distribution of the vegetation has not been published (Gentry, 31)* 2

Forrest Shreve (in Gentry, 31) states that Gentry's collection made between 1933 and 1939 is one of the most faithful records of the flora of the Rio Mayo Basin. Gentry collected about 3200 specimens representing 1245 species and varieties, some of which have been deter­ mined as new. In his publication Rio Mayo Plants he brings together the records of the collections, observations on the distribution and composition of the vegetation, and information on the geography and physical features of the valley. He did not include keys for the iden­ tification of the plants listed in the flora *

The chief purpose of this study, then, is to provide a means for identifying the species cited by Gentry in the account of his ex­ ploration through the Rio Mayo Valley. It is supposed, of course, that a paper such as this will add much to the usefulness of the book, and in addition, aid the many students having an interest in the flora and a need for the identification of the plants of the Rio Mayo Basin. PROCEDURE

In order to attain the objective of the study5 keys are provided to the families, to the genera, and to the species. In a few instances the infraspecific categories of subspecies or variety are keyed„

The General Key follows that of Arizona Flora by Kearney and

Peebles (63). The order of Families is that of Genera Siphonogamarum by Da11a Torre and Harms (18). Within the family the genera are ar- - . ranged alphabetically, except for Leguminosae, Gramineae and Compositae where they are arranged in Tribes or Subfamilies» The non indented

Mdichotomous key" is employed throughout„ It can be short and limited to a single couplet, or it may be composed of an extensive series of these o

The keys and descriptive data were, in general, adapted from

Arizona, Flora by Kearney and Peebles (63), Trees and Shrubs of Mexico by Standley (145), Vegetation and Flora of the Sonoran Desert by Shreve and Wiggins (141), Flora of Guatemala by Standley and collaborators

(146), Manual of the Vascular Plants of Texas by Correll and Johnston

(15), Grasses of Southwestern United States by Gould (35), Manual of the

Grasses of the United States by Hitchcock (47), Ferns and Fern Allies of Texas by Correll (14), Ferns and Fern Allies of Chihuahua, Mexico by

Knobloch and Correll (67), and various monographs and revisions• Also, numerous portions of North American Flora by various authors were uti­ lized as sources of information for keys and descriptions* 4

Monographss revisions and portions of North American Flora are cited after the name of the taxon under consideration by number in pa­ rentheses. Citation of these publications5 correspondingly numbered3 is given in the list of References.

Descriptions to families, genera, and species are:not included in this work. However, they will be found in the mentioned citation*

General comments of each species to aid in the identification are given in Rio Mayo Plants under each specific name. The information includes distribution and abundance of each species in the Rio Mayo Valley, habitat preference of each species, and a brief description of the living plant, including its seasonal development. When possible Gentry supplied the common name applied to the plant by the Indians of the area as well as any use they made of it.

Reference marks, * and -f, placed before any specific name indid­ eates it differs from that of Gentry’s book. The asterisk (*) indicates a change in nomenclature resulting from synonym, and the plus (+) indi­ cates the specimen was originally misidentifled. The nomenclatural changes are listed in alphabetical order in the appendix, and below each new name is the corresponding name in the booko KEY TO THE DIVISIONS

1. Fern or fernlike plants without true seeds; reproduction by

means of spores...... I. PTERIDOPHYTA p. 6

1. Plants producing true seeds containing embryos ......

...... II. SPEKMATOPHYTA p. 15 '

5 lo PTERID OPHYTA

Key to the Families of Pteridophyta lo Leaves scale-like or elliptic to subulate3 sometimes coalesced into

cylindrical sheaths around the stem. .2 lo Plants with broad or narrow, entire, toothed, pinnate, pinnatifid

or variously dissected blades» •••'•o 4

2(1). Stems conspicuously jointed, the internodes, hollow, prominently

ridged; sporangia elongate, borne on the under side of peltate

scales that are grouped into terminal spike-like cones » » • o »

...... 1. EQUISETACEAE p. 8

2. Stems not jointed, solid; sporangia borne on the leaf bases or

axillary . . • 0 •' . • - . . • • . • • « » « • ...... • » « 3

3(2). Terrestrial or more or less epiphytic plants; stems dichotomously

branched with minute remote alternate scale-like leaves;

sporangia somewhat depressed by 2-lobed minute sporophylls on

the upper part of the branches .•••..» 2. PSILOTACEAE p. 8

3 o Small terrestrial or lithophytic plants of spreading habitat; stems

conspicuously branched; leaves mostly shortly subulate, or

sometimes scale-like, minute; approximate to closely imbricate;

sporangia of two kinds (heterosporous plants), some with nu­

merous microspores (male), other containing 1-4 rather large

megaspores (female) . . » „ . .5» SELAGINELLACEAE p. 13

6 7

4(1). Plants not succulent, usually with membranous to coriaceous leaf

tissue, the blades circinate in vernation; sporangia borne on

the back of on the margin of the blade, the annulus present;

pro thallium visible«, . .3. POLYPOD TAG EAE p <, 8

4. Succulent or herbaceous terrestrial or occasionally epiphytic

plants; leaves not circinate in vernation, divided into fertile

and sterile parts; sporangia lacking an annulus, borne in a

stalked terminal spike or panicle-like pinna; prothallium.sub­

terranean « ...... 4* OPHIOGLQSSACEAE p« 13 lo EQUISETACEAE. Horsetail Family

1 o Equisetum Lo

One species...... * ...... oEquisetum laevigatum

2 o PSILOTACEAEo Whisk Fern Family

1• Psilotum Lo

One species ...... o Psilotum nudum

3« POLYPODlACEAEo Fern Family

!• Leaves simple, pinnatifid or once pinnate, pinnae of primary divi­

sions entire, toothed or pinnatif id» 2. lo Leaves twice pinnate or more dissected 9

2(1)o Primary divisions or pinnae with margins entire, undulate,

irregularly toothed or incised, not pinnatif id . . ® «,»«,»» 3

2. Primary divisions or pinnae distinctly pinnatif id® • » . » . 6

3(2)o Sori sub-marginal; indusia formed entirely or in part by the •

revolute margins of the fronds or its segments • • • ® • 4

3o Sori dorsal; indusia when present not formed by the somewhat modi­

fied leaf margins, - 0 « o « 5

4(3), Leaves densely pubescent or scaly (or both), sometimes covered

with white powder beneath®...... ® 7. Notholaena p® 12

4® Leaves not as above® ® ® ® ® ® ® ® . . ® ® * ® • ® ®8® Pellaea p® 13

5(3). Rock ferns with short-creeping to erect scaly rhizomes; sori

narrowly linear to oblong, borne just below the tips of ultimate

branches of veins; fronds pinnate or pinnatifid, mostly firm or

evergreen; stipes dark brown to black, and shining at least at

base ...... 2. Asplenium p® 11 5 e Woodland ferns with 4:hicka long-creeping scaly rhizomes, the scales

ciliate; fronds light green, thin, membranaceous; stipes

stramineous, nearly scaleless; veins reaching the margins of

the segments...... 6. Thelypteris po 11

6(2)» Blades pentagonal, white and powdery beneath or densely hispid

pubescent # « « ® @ @ @ o » « « © © © © © • » « © © » « © © © <© 7

6. Blades not pentagonal, glabrous to laxly pubescent •••••'••• 8'

7 (6) © Blades densely hispid pubescent on both surfaces, not waxy;

rhizome slender, widely creeping...... 3© Bommeria p© 11

7 © Blades white and powdery beneath; rhizome multicipital © © © © © © - ©

© © ...... © ...... © . © © 7 © Notholaena p© 12

8(6), Sori linear to elliptic,not orbicular in shape, these parallel

to the midrib in one or more chain-like rows on transverse

anastomosing veinlets© © © © © © © © ® • . .9* Woodwardia p © 13

8© Sori orbicular to reniform-orbicular; acicular unicellular hairs

(at least on the rachis and costae above) ciliate, the minor

axis not decurrent; ferns with long-creeping scaly rhizome, the

scales ciliate; fronds thin membranaceous; veins reaching the

margins of the segments© 6© Thelypteris p© 11

9(1). Large to medium plants (about 1 m© tall or more) with densely

hairy rhizome, not scaly; sori marginal, globular, enclosed in

a cup-like indusium opening at summit and partly adhering to

reflexed teeth of the frond. ©©©».©« 5. Dennstaedtia p© 11

9© Small plants, usually less than 1 m© tall; rhizome scaly, sometimes

also hairy; sori marginal or nearly so, or borne in lines along

the veins and then lacking an indusial covering© ...... 10 10

10(9)- Sporangia borne on the-veins on the under, side of a reflexed

marginal lobe...... 1. Adiantum p. 10

10o Sporangia not borne on a marginal lobe, but often borne on the leaf

surface under a marginal lobe ...... 11

11(10). Margin strongly modified and reflexed, elongate and continuous;

pinnae scaleless, mostly glabrous; rhizome multicipital or

creeping © ® ® . © . « * « © @ . © . « « » ® . .8© JPe^llsue^ p . 13

11. Margin reflexed or not, mostly interrupted...... 12

12(11). Indusia formed by reflexed margin of segments usually wanting;

the lower surface of frond white and powdery beneath .....©

...... •••••••*. 7. Notholaena p. 12

12. Indusia well developed, lower surface glabrous or pubescent, not

white powdery; fertile and sterile fronds similar; reflexed

Indusial margins of segments whitish and membranaceous .....

...... 4. Cheilanthes p. H

1. Adiantum

1. Rhizome laxly paleaceous, the scales small, light brown in color; / sterile segments toothed, the veins running to the teeth; sori

solitary on lobes, oblong-lunate . . . Adiantum capillus-venerls

1. Rhizome slender and widely creeping or sometimes rather stout and

short, the scales lanceolate, acuminate, tan colored or brown­

ish; sterile segments not toothed, the veins several times

dichotomously forked and running to the sinuses (if present);

sori usually 3 or 4, reniform...... Adiantum, .poretil • ■ ■ 1 1 .2.o Asplenium

One species „ o«.-. • » » . » » « Asplenium palmeri .

3 - Bommeria

One species „ * . « o . , « » c * • . • . « . ' . ■ • . .Bommeria hispida

4. Cheilanthes (162) lo Rhizome multicipital, short creeping or ascending; blades pubescent

on both surfaces; stipes erect* 5-15 cm. long* reddish brown*

glandular«puberulent; Indusia coarsely crenate* formed from

modified margins of segments . . . . * . .Cheilanthes kaulfussii

I. Rhizome slender* widely creeping* or if multicipital* the divisions

distinctly short creepingo . . . . ® » «, • • . . . • * 0 o • 2

2(1)o Blades broadly triangular ovate* densely glandular-puberulent on

both surfaces* branches of rhizome short creeping* , • - « a ... -«

* ...... * * . * ...... Cheilanthes kaulfussii

2* Blades more or less lance-ovate* not glandular* conspicuously scaly*

the larger ones ciliate at base; ultimate segments hairy and

orbicular in shape; indusia narrow* obscured by tomentum and

scales; widely creeping rhizomes * . . . Cheilanthes lindheimeri

5* Pennstaedtia (90*154)

One species. * * ...... » .-Dennstaedtia distenta

6 * Thelypteris

I. Presence of small* reniform and persistent indusia, usually densely

hirsute; pinnae spreading* linear-lanceolate* up to 12 cm. long*

the lowermost pair usually noticeably longer than the other; 12

veins 6-10 pairs, simple./ oblique with the lowest pair running

to the sinus and confluent . @ ...... *Thelypteris puberula

1. Indusia not present; stipes stramineous or sometimes brownish? much

shorter than the blades; the lowest pair of pinnae much

reduced. . . . . © . . . ® ...... » . . . . «, . . . 2

2(1). Sori supra-medial; veins about 10 pairs, oblique, simple, the

lowermost pair running to the margin above the sinus * «, . , .

o.oo.o... *Thelypteris rudis

2. Sori sub-medial on the veins, elongate; pinnae less than or cut to

about midway to the midrib • • • •. • • 0 • • • o . • • • • « 3

3(2). Plants weakly erect to erect ascending, up to 5 dm. tall; pinnae

cut less than midway to the midrib .... . *Thelypteris pilosa

3. Larger plant with more.deeply cut pinnae, often cut to about midway

to the midrib. .*Thelypteris pilosa var. major

7. Notholaena (41,153)

1. Blades ovate-pentagonal to ovate-lanceolate, gradually and evenly

contracted and pinnate above, bipinnate-pinnatifid below;

indument wholly ceraceous; scales of rhizome lanceolate or

lanceolate-subulate, the broader ones usually with a dark brown

to black central stripe; stipes terete, somewhat lustrous

nigrescent . . ' . . . . . <, • « ...... « .Notholaena Candida

1. Blades linear to linear-elliptic or oblong-lanceolate; indument of

scales or hairs, or both, not ceraceous. » 0 ••••-• e 2

2(1). Pinnae not sc^ly, densely tomentose beneath, silvery villous

above; blades linear to linear-lanceolate, usually gradually 13

narrowed at the base, pinnate-pinnatifid; rhizome scales rigid,

incurved, deep castaneous in color, the margins light scarious „

...... o ...... o *Notholaena aurea

2. Pinnae densely scaly beneath, ovate to ovate-elliptic, sub-obtuse to

sub-acute provided above with minute white stellate scales or

essentially glabrous and deep green with age; rhizome scales

slender, linear to linear-subulate, ferruginous, pectinate-

ciliate to serrulate ...... Notholaena sinuata

8. Pellaea

One species...... ^Pellaea ovata

9. Woodwardia

One species...... Woodwardia spinulosa

4. OPHIOGLOSSACEAE. Adder's Tongue Family

1° Bothrychium

One species...... Bothrychium sp.

5. SELAGINELLACEAE. Selagine11a Family

1. Selaginella 7

1. Plants not rosulate, assurgent or recurved ascending nearly erect,

rooting only at the base; leaves linear-lanceolate in shape;

terminal setae prominent (about 1 mm. or more long) forming a

conspicuous tuft at the ends of sterile shoots, the margins

ciliate with 15-20 cilia on each side. . . Selaginella r up incola

1. Plants in basal rosettes, dorsiventral ...... 2 14

2(1). Blades stipitate or nearly.so; leaves bright yellowish-green on

upper surface? silvery on the lower one. *Selaginella pallescens

2 e Blades and leaves not as above; leaves elliptic-shaped3 minutely

ciliolate on the greenish margins9 not whitish marginate,

setaceous or sharply cuspidate at apex . „

. 0 » e » e o 0 e , o ...... ^Selaginella novoleonensis H o SPERMATOPHYTA

Key to the Classes of Spermatophyta

Stigma none; ovules and seeds not enclosed5 borne on adaxial side

of scale or bract« •••••••-•.» Class Ic GYMNOSPEKMAE p« 16

. Stigma(s) present; ovules and seeds in a closed cavity (ovary) * , o

...... * . . oClass II. ANGIOSPERMAE p. 18

15 Class lo GYMNOSPERME

Key to the Families of Gymnospermae lo Palm-like plants; leaves pinnate, basal or clustered at the end of

a trunk; dioecious condition , » «, „ <> . * » 1 * CYCADACEAE p * 17 lo Plants not as above; leaves simple, entire or denticulate, narrow,

usually, needle-like or scale-like; monoecious conditione • * „ 2

2(1)o Leaves opposite, short, scalelike . . . « * 4. CUPRESSACEAE p« 17

2 o Leaves arranged spirally, elongate, narrowly linear or needle-like e

. . o ...... 3

3(2)• Leaves single or in fascicles; ovule scale subtended by bract;

scale peltate, ...... , . . . 2. PINACEAE p, 17

3, Leaves single; bract not present under peltate ovule scale » , 0 « »

.. . .3. TAXODIACEAE p. 17

16 I. CYCADACEAE. Cycad Family

1. Dioon

One species...... Dioon purpussii

2. PINACEAE. Pine Family

1. Leaves in fascicles (3-5), needle shaped; bracts shorter than the

cone scales...... 1. Finns p.

1. Leaves single, narrowly linear; bracts longer than the cone scales,

conspicuously 2-lobed, and aristate at apex.2. Pseudotsuga p.

1. Pinus

1. Bracts below needle fascicles decurrent on twigs; leaves 3 per

fascicle ...... Pinus lumholtzii

1. Bracts below needle fascicles not decurrent on twigs; leaves 5 per

fascicle e e o a e a . ... o o . ...a...... 2

2(1). Leaves 15-40 cm. long; cones 10-45 cm. long . . .Pinus ayacahuite

2. Leaves up to 15 cm. long, usually shorter; cones 10-25 cm. long. . .

. . . . '. . a ® ® O o . . * a . . * . . * . . . . IXUiS .

2. Pseudotsuga

One species...... Pseudotsuga mucronata

3. TAXODIACEAE. Bald Cypress Family

1. Taxodium

One species...... Taxodium mucronatum

4. CUPRESSACEAE. Cypress Family

1. Cupressus

One species...... Cupressus arizonica Class H e ANGIOSPEKMAE

Key to the Sub-Classes of the Angiospermae

1o Cotyledon usually 1; leaves usually parallel-veined; flower parts

commonly in threes , * * . . Sub-class I » MONOCOTYLEDONEAE p » 19

1, Cotyledon usually 2; leaves usually netted-veined; flower parts

commonly not in threes . ♦ « .Sub-class 11. DIC OTYLED ONEAE p. 55

18 Sub-class lo MONOCOTYLEDONEAE

Key to the Families of Monocotyledoneae

!• Plants strictly aquatic, wholly immersed; perianth none; flowers

unisexual, the staminate with a double sheath-like perianth,

the pistillate naked; leaves serrulate to spinulose-dentateo •

• o ...... 1 c NAIAD AC EAE p. 22

I, Plants terrestrial (in one family epiphytic), or only partly sub­

merged ooooeo oooooo ooooo ooooeooo o oo2

2 (1) . Perianth lacking ...... o.„ 3

2 o Perianth present o » ......

3(2)o Stems round, usually hollow, except at the nodes; leaves 2-ranked 5

the sheaths commonly split on one side; fruit a caryopsis. « , •

o o o ...... 3c GRAMINEAE p« 22

3* Stems trigonous, usually solid; leaves 3-ranked, with closed

. sheaths; fruit an achene • • » • o e • e 4. CYPERACEAE p, 33

4(2) o Carpels 3- to many, distinct,...... , ...... 5

4. Carpels 1-3, united into a single pistil , , » , » » , , , , , , , 6

5(4), Plants herbaceous; flowers not in spathes; carpels more than

three; leaves not fan-shaped , » ...... 2, ALISMACEAE p, 22

5, Plants tree-like, with a tall trunk; flowers in spathes; carpels

3; leaves fan-shaped, many ribbed, deeply lobed, 5, PALMAE p, 38

6(4), Leaves pinnately compound or the blade flabelliform, many

ribbed; plant tree-like, the trunk unbranched, , 5» PALMAE p, 38

. 19 20

6, Leaves mostly simple, not flabelliform or many ribbed; plants her­

baceous, or if tree-like the leaves simple » » » . » » » . » » 7

7(6). Herbage bearing water-absorbing scales, at least when young;

plants often epiphytic, growing on the branches of trees . . . .

...... 6. BROMELIACEAE p. 39

7. Herbage not clothed with water-absorbing scales; plants not

epiphytic ...... , ...... 8

8(7) . Ovary superior ...... „ . 9

8 o Ovary inferior or partly so. ^ • 13

9(8). Perianth segments glume-like, green to brown or purplish. . . . .

...... 9. JUNCACEAE p. 43

9 o Perianth segments not glume-like . * ...... 10

10(9). Functional stamens 3; inflorescence in spathe-like leaves or

b r a c t s ...... 11

10o Functional stamens 6; inflorescence not in spathes...... 12

11(10). Segments of the perianth sharply differentiated, the outer

ones green, sepal-like, the inner ones petal-like, fugacious;

plants terrestrial ...... 7. COMMELINACEAE p. 40

11. Segments of the perianth similar and similarly colored; plants

aquatic or semiaquatic ...... 8. PONTEDERIACEAE p. 43

12(10). Segments of the perianth sharply differentiated, the outer

ones green, sepal-like, the inner ones petal-like, fugacious,

not bearing glands; flowering stems not from an onion-like

b u l b ...... 7. COMMELINACEAE p. 40 12 o Segments of the perianth not sharply differentiated, or if so

(Genus Calochortus) , then the inner ones bearing a conspicuous

fringed gland; flowering stems from an onion-like bulb „ * . . «

...... 10. LILIACEAE p» 43

13(8)o Flowers unisexual; twining plants; leaves cordate and netted-

v e i n e d ...... 12. DXOSCOREACEAE p. 49

13. Flowers, perfect; not twining plants; leaves narrow, parallel

veined ...... 14

14(13). Stamens 1 or 2; flowers zygomorphic . .14. ORCHIDACEAE p. 50

14. Stamens 3 or 6 ; flowers regular or nearly so...... 15

15(14).....Stamens 6 ...... ,11. AMARYLLIDACEAE p. 47

15. Stamens 3 ...... 13. IRIDACEAE p. 49 22

1. NAIADACEAE. Naiad Family

1. Naias

One species...... Naias flexilis

2. ALISMACEAE. Water-Plantain Family

1. Echinodorus

One species...... Echinodorus cordifolius

3. GRAMINEAE. Grass Family

Key to the Sub-families I 1, One- to several florets per spikelet; disarticulation of spikelets-

above the glumes; spikelets, or at least the fruits, laterally

compressed ...... A. FESTUCOIDEAE p. 22

1 o Two (only) florets per spikelet, one, the terminal is fertile, and

below it a sterile one; disarticulation of spikelets below the

glumes; spikelets, or at least the fruits, dorsally compressed «*

...... B, PANIC01DEAE p. 27

A. Sub-family: Festucoideae

Key to the Tribes:

1. Plants woody, the culms perennial; spikelets several flowered. * . .

...... Tribe II. Bambuseae p. 25

1. Plants herbaceous, the culms annual...... 2

2(1). Inflorescence of one to several spikes or spicate racemes . . . 3

2. Inflorescence an open or contracted panicle, occasionally a raceme . 23

3(2). Spike or spicate raceme bilateral, solitary; spikelets three at

a node, falling in clusters from a continuous rachis „ . ,

o ...... Tribe V» Zoysieae p„ 27

3 o Spike or spicate raceme unilateral • . . Tribe III. Chlorideae p. 25

4(2)o Spikelets with 2 or more perfect florets; glumes shorter than

the first lemma...... Tribe IV. Festuceae p. 26

4. Spikelets with one perfect floret and no reduced floret above, . . 5

5(4). Spikelets in short-pedicellate groups of three, the central

spikelet perfect, awned, the two lateral ones staminate or

neuter, awnless; annual plants . . . . . Tribe V. Zoysieae p. 27

5 e Spikelets not in clusters. • . Tribe I. Agrostideae p. 23

Tribe I. Agrostideae

1. Fruit indurate, terete, awned; callus well developed, oblique,

bearded; awns trifid, the lateral divisions minute ......

...... 1. Aristida p. 24

1. Fruit thin or firm, but not indurate; callus not well developed;

awns unbranched...... 2

2(1). Lemma awned, 3-nerved, the lateral nerves usually obscure . . . .

...... «...... 2. Muhlenbergia p. 24

2. Lemma awnless...... 3

3(2). Lemma 3-nerved; caryopsis cylindric or somewhat compressed

dorsally, usually not falling readily from the floret......

...... 2. Muhlenbergia p. 24

3. Lemma 1-nerved; caryopsis obovoid, usually strongly compressed lat­

erally, falling readily from the florets . .3. Sporobolus p. 25 24

lo Ar1stIda

One species...... Aristida ternipes var» minor

2. Muhlenbergia (46)

1 „ Plants annual • ••'•••• e o e ...... 0 2 ‘

1» Plants perennial ...... 4

2(1). Glumes ending abruptly by a narrow scabrous awn 1-2 times as long •

as the body, the base broad...... Muhlenbergia tenella

2. Glumes awnless, often acute or acuminate ...... 3

3(2). Second glume about 2 mm. long ...... Muhlenbergia quitensis

3. Second glume 1 mm. long or less ...... Muhlenbergia microsperma

4(1). Plants with creeping rhizomes; blades narrow, usually 1.5 mm. or

less broad, short; culms 1-3 meters high, woody at base, as much

as 6 mm. thick, freely branching at the middle and upper nodes .

...... Muhlenbergia dumpsa

4. Plants without creeping rhizomes . . o ...... 5

5(4) . Second glume 3-toothed; lemma about 4 mm. , hirsute.

...... ^Muhlenbergia montana

5. Second glume usually acute or awned, never distinctly 3-toothed. . 6

6(5). Lemma awnless ...... 7

6. Lemma awned, the awn as long as, or longer than, the body. . . . . 8

7(6). Panicle spike-like, seldom over 1 cm. thick; glumes about half to

nearly as long as the lemma...... Muhlenbergia rigens

7. Panicle narrow, but not spike-like, usually thicker than species

above and about 20 cm. or more longer; glumes about as long as

or slightly exceeding the lemma...... Muhlenbergia emersleyi 25

8 (6). Culms robust, mostly 60-120 cm. tall, the basal tuft of over­

lapping sheaths strongly compressed-keeled; glumes about as

long as or slightly exceeding the lemma, this 2-3.5 mm. long,

usually pubescent below...... Muhlenbergia emersleyi

8 . Culms usually not robust, 40-70 cm. tall, the lower sheaths not

crowded and compressed-keeled; glumes distinctly shorter than

the lemma, this about 3.5 mm. long, glabrous ...... * . „

...... o ...... Mihlenbergia elongata

3. Sporobolus

One species...... Sporobolus microspermus

Tribe II. Bambuseae

1. Arundinaria

One species...... Arund inaria longifolia

Tribe III. Chlorideae

1. Spikelets with one perfect floret and one or two rudimentary florets

above it; lemma variously lobed or dentate, 3-awned......

...... 1. Bouteloua p . 25

1. Spikelets with 2-to several perfect florets; lemma: entire or

minutely bifid, awnless or with a single awn 2 . heptochloa p. 26

1. Bouteloua

1. Spikelets not pectinately arranged, the spikes falling entire at

maturity ...... 2

1. Spikelets pectinately arranged, the spikes persistent, the florets

falling from the persistent glumes ...... 5

2(1). Plants annual; spikes very narrow, abruptly spreading above, the

* rachis sharp-pointed at base ...... Bouteloua aristidoides 26

2. Plants perennial; spikes relatively broad, the rachis not sharp-

pointed at base...... * , * . . 3

3(2). Spikes many, usually 20 or more; spikelets appressed to deflexed.

...... Bouteloua curtipendula

3. Spikes usually fewer than 1 5 ...... 4

4(3). Glumes densely pubescent; base of the plant not rhizomatous;

culms 30-50 cm. tall; blades about 1-1.5 mm. wide, the margins

scabrous; spikes about 1 cm. long; lemma 6-7 mm. long......

...... o Bouteloua eludens

4. Glumes glabrous or scabrous; base of the plant hard, rhizomatous;

culms 60-80 cm. tall; blades about 2-3 mm. wide, the margins

papillose-ciliate toward the base, sometimes papillose only;

spikes 2-3 cm. long; lemma about 8 mm. long. .Bouteloua radicosa

5(1). Spikes normally 2, rarely 1 or 3; body of the lemma about 4 mm.

long; spicate branches relatively large and thick...... » .

...... o ...... Bouteloua gracilis

5. Spikes 3-8; body of the lemma less than 4 mm. long; spicate branches

relatively small and narrow...... Bouteloua rothrockii

2 . Leptochloa

One species...... ^Leptochloa filiformis

Tribe IV. Festuceae

1. Lemmas awned; first glume 3-nerved; perennial plants ......

...... 1. Bromus p. 27

1. Lemmas awnless; first glume 1-nerved; annual or perennial plants . .

...... 2 . 27

2(1). Lemmas 3-nerved; spikelets 8- or more flowered; annual plants . .

...... • 2 o Era%rostis p . 27

2. Lemmas 5-nerved; spikelets mortly 3- or 4-flowered; perennial

plants . o ...... 3. Poa p. 27

1. Bromus

One species...... *Bromus anomalus

2. Eragrostis

1. Plants with minute glands on the panicle branches, or on the keel

of the lemmas; blades 10-20 cm. long; spikelets 2.5-3 mmo wide,

12-40 flowered; caryopsis ellipsoidal to subspherical, 0.5-0o8

mm. long, about 0.4 mm. w i d e ...... Eragrostis cilianensis

1. Plants not glandular on the branches or lemmas, but with a few

scattered glands on the sheaths; blades 5-10 cm. long; spikelets

1.8-2 mm. wide, 8-13 flowered; caryopsis short, cylindric,

0.8-1 mm. long, about 0.6 mm. w i d e Eragrostis mexicana

3. Poa

One species...... Poa involuta

Tribe V. Zoysieae

1. Aegopogon

1. Lobes of glumes acute or awned, firm, purplish......

...... Aegopogon cenchroides

1. Lobes of glumes broad, obtuse, papery...... Aegopogon tenellus

B . Sub-family: Panicoideae

Key to the Tribes:

1. Glumes membranaceous, the sterile lemma like the glumes in texture 28

1. Glumes indurate; fertile lemma and palea hyaline or membranaceous 9

the sterile lemma like the fertile one in texture. , „ . 3

2(1). Fertile lemma and palea thinner than the glumes; sterile lemma

awned from the notched summit. . . . .Tribe II. Melinideae p. 30

2 o Fertile lemma and palea indurate or at least firmer than the

g l u m e s ...... Tribe III. Paniceae p. 30

, 3(1). Spikelets unisexual, the pistillate below, the staminate above,

in the same inflorescence...... Tribe IV. Tripsaceae p. 33

3. Spikelets in pairs, one sessile and perfect, the other pedicellate

and usually staminate or neuter. . .Tribe I. Andropogoneae p. 28

Tribe I. Andropogoneae

1. Spikelets awnless; racemes short, partly enclosed in the sheaths;

freely branching annual...... 2. Hackelochloa p . 29

1. Spikelets awned...... 2

2(1). Awn of fertile lemma 3-8 cm. long or more; hairy-pointed callus

present at the fertile spikelet, formed of the attached sup­

porting rachis joint or pedicel; primary spikelet fertile, the

pedicellate one sterile; lower pairs of spikelets all staminate

or neuter 3 . Heteropogon p. 29

2. Awn of fertile lemma 0.7-3 cm. long; hairy-pointed callus not

present at the fertile spikelet, the rachis disarticulation

immediately below the spikelet ...... 3

3(2). Racemes of several to many joints, solitary, digitate or aggre­

gate in panicles ...... 1. Andropogon p. 29

3. Racemes reduced to one or few joints, these mostly peduncled in a

subsimple or compound panicle...... 4 29

4(3) • Pedicellate spikelets staminate „o „ 5. Sorghum p „ 30

4. Pedicellate spikelets wanting, only'the pedicel present, . . „ * * .

« o o o . . o . o . . o o,o o . . . . .4o Sorghastrum p . 29

1. Andropogon

1. Plants annual; outer glumes of sterile or pedicelled spikelet

enlarged; sessile spikelet 5 mm. long; awn of the fertile lemma-

4-5 cm. long ...... o ... . Andropogon fastigiatus

1. Plants perennial; outer glumes of sterile spikelet not enlarged;

sessile spikelet mostly 6-8 mm. long; awn of the fertile lemma

5-12 mm. long...... Andropogon cirratus

2. Hackelochloa

One species...... Hackelochloa glandularis

3. Heteropogon

1. Coarse annual; culms usually more than 1 m. high; first glume of

the staminate spikelet with a row of rather large, distinct,

impressed glands on the mid-nerve. . . Heteropogon melanocarpus

1. Perennial; culms slender, usually less than 1 m. high; first glume

of the staminate spikelet without impressed glands, but

variously hirsute or sparsely papillose-hispid ...... » .

...... o ...... Heteropogon contortus

4. Sorghastrum (98)

1. Inflorescence short, 8-12 cm. long; spikelets few; culms 60-80 cm.

high ...... Sorghastrum nudipes

1. Inflorescence larger, 20-50 cm. long; spikelets numerous; culms 1 m,

high, or much longer ...... Sorghastrum nutans 30

' 5 . Sorghum

1. Coarse, rhizomatous perennial; spikelets readily disarticulating

from the pedicel, the pedicellate usually staminate, equalling

the sessile. Sorghum halepense

1. Annual plants; spikelets tardily disarticulating from the pedicel,

the pedicellate usually empty, shorter than the sessile one* » »

...... o . . o Sorghum vulgare var. sac char a turn

Tribe II. Melinideae

1. Arundinella

One species...... Arundinella palmeri

Tribe III. Paniceae

1. Pedicels or peduncles bearing one to several bristles at the base

of the spikelets ...... 2

1. Pedicels and peduncles without bristles...... 3

2(1). Bristles persistent and not falling with the spikelets at

maturity ...... 6 . Setaria p. 33

2. Bristles deciduous, falling with the spikelets at maturity .....

...... 5. Penniseturn p. 32

3(1). Glume or sterile lemma awned; first glume about as long as the

second, with an awn to 3 times the length of the body; culms

creeping ...... 2. Oplismenus p. 31

3. Glumes and sterile lemma awnless ...... 4

4(3). Spikelets plano-convex, in pairs, 2.2-2.6 mm. long, arranged in

two rows on one side of the rachis; perennial plants ......

...... 4. Paspalum p . 32 '' 31

4 o Spikelets usually in panicles, not or not all in regular rows. . » 5

5(4). Culms woody, freely branched above, often viny; fruits with a

tuft of hairs at the tips...... 1. Lasiacis p. 31

5. Culms herbaceous; fruits without a tuft of hairs at the tips ....

. o ...... o o ... o ...... 3. Panic urn p. 31

1. Lasiacis (44)

1. Blades narrowly lanceolate, usually 8-10 times as long as wide;

panicle open, loosely flowered; spikelets 4-5 mm. long . . . » *

. o o o . o ...... o ...... Lasiacis sorghbides

1. Blades ovate-lanceolate or elliptic, usually asymmetrical; panicles

often compact, or at least the branches, compactly flowered;

spikelets 3-4 mm. l o n g ...... Lasiacis ruscifolia

2 . Oplismenus (45)

1 o Plants annual; rachis of racemes densely villous; spikelets 3 mm.

long, usually densely villous; awns antrorsely scabrous......

o.o.ooo...... Oplismenus burmanni

1. Plants perennial; rachis of racemes scabrous; spikelets 3-3.5 mm.

long, glabrous to sparsely pilose; awns smooth . . . . 0 . . . <,

...... oo.o.o Oplismenus hirtellus

3. Panicum (99)

1. Plants annual...... 2

1. Plants perennial ...... 4

2(1). Inflorescence consisting of several more or less secund spike­

like racemes; fruit transversely rugose; spikelets 3.5-3.8 mm.

long; sheaths and.blades glabrous to papillose-hispid......

...... o o.ooo.. .Panicum arizonicum 2. Inflorescence a more or less diffuse panicle; fruit not trans­

versely rugose o » o . . o „ e , o . . b e e o e . . o o o O 3

3(2)« Spikelets about 1 »3 mm. long, pubescent; second glume and sterile

lemma not pointed beyond the fruit; blades ovate-lanceolateo o •

. o o o .. o . . .Panicum trichoides

3. Spikelets 3.0-3.5 mm. long, usually glabrous; second glume and

sterile lemma pointed beyond the fruit; blades linear. . . . . «,

...... o ...... Panicum so no rum

4(1). Basal leaves distinctly different from those of the culm, forming

a winter rosette; culms 20-55 cm. high, not bulbous at base;

panicle 5-10 cm. long, rather loosely flowered; spikelets 1.6-

1.8 mm. long, at maturity, usually puberulent; second glume and

sterile lemma equalling the fruit at maturity, the fruit 1.4-

1.5 mm. long ...... Panicum sphaerocarpon

4. Basal leaves similar to those of the culm, not forming a winter

rosette; culms 1.0-2.0 m« high, distinctly bulbous at base;

panicle 20-50 cm. long, rather many flowered; spikelets 3.5-

4.2 mm. long at maturity, glabrous; second glume shorter than

the fruit and sterile lemma, the fruit 3 .2-4.0 mm. long. . . . .

...... Panicum bulbosum

4. Paspalum

One species ...... Paspalum langei

5. Pennisetum

One species . . . o ...... Pennisetum karwinskii 33

6 . Setaria

1. Bristles below each spikelet 5 or more; fertile lemma coarsely

transverse-rugose; plants perennial9 usually rhizomatous, with

hard culm bases and usually wiry culms . . . oSetaria geniculata lo Bristles below each spikelet 1-3; fertile lemma finely cross-lined

or nearly smooth; plants annual. » . . . » .. Setaria grisebachii

Tribe IV. Tripsaceae

1. Tripsacum

One species...... Trips a cum lanceolatum

4. CYPERACEAE (75). Sedge Family

1. Flowers unisexual5 the staminate and pistillate in the same or in

different spikelets; achenes completely surrounded by the

perigynium ...... * . . . . . 1 . Carex p. 34

1. Flowers all perfect; achene not enclosed by the perigynium . . . * 2

2,(1). Inflorescence of a single terminal spikelet; involucral leaf not

present„ ...... 3. Eleocharis p. 37

2 o Inflorescence usually of several spikelets; involucral leaf

present...... 0 .. ... o ...... 3

3(2). ‘ Scales of the spikelets evidently 2-ranked, the spikes often

strongly flattened; perianth bristles none . . .2. Cyperus p. 33

3 o Scales of the spikelets spirally imbricated, the spikes terete or

sometimes slightly flattened; perianth bristles present or

not...... o ...... 4

4(3). Flowers without inner perianth scales ...... 5

4». Flowers with 1 or 3 inner perianth scales...... 6 34

5(4). Style and its branches rather flattened, fimbriate, its base

noticeably enlarged; perianth bristles none; achene lenticular .

o ...... 4. Fimbristylis p* 38

5. Style and its branches terete, entire, its base not noticeably

enlarged; perianth bristles usually present; achene plano­

convex ...... 7. Scirpus p » 38

6(4). Perianth consisting of 3 broad stipitate scales, these alter-- ,

nating with retrorsely barbed bristles; stamens 3; perennial

plant with relatively broad leaves « ...... 5. Fuirena p « 38

6 . Perianth consisting of one very thin hyaline basal scale, this

minute; bristles not present; stamen 1; annual plant with

narrow leaves...... 6 . Hemicarpha p. 38

1 o Carex

1. Stigmas 3; achenes trigonous; perigynia pubescent throughout, many-

ribbed, 4-10 on a spike, the beak about 0.5 mm. long; pistillate

spikes few-(2-3)flowered; staminate spike usually longer than

pistillate, about 10-30 mm. long ...... Carex leucodonta

1. Stigmas 2; achenes lenticular; perigynia glabrous throughout;

staminate spike usually the same size or shorter than pistil­

late o o o ...... 2

2(1). Lateral spikes peduncled, or if sessile, then elongate, the

terminal spike usually staminate; leaves 3-12 mm. wide;

perigynia conspicuously nerved on both sides, the beak markedly

bidentate; culms strongly phylopodic .... .Carex nebraskensis 35

2. Lateral spikes sessile, short, the terminal spike usually not

entirely staminate; leaves 1*5-3 mm. wide; perigynia lightly

several nerved dorsally and nerveless ventrally, the beak not

markedly bidentate, but usually serrulate. „ .Carex praegracilis

2. Cyperus

1. Style 2-brahched; achene compressed or biconvex: Sub-genus Pycreus «,

. . ' . . . 2

1. Style 3-branched; achene trigonous , = o o. * . 6

2(1). Spikelets linear-oblong or lanceolate; scales densely imbricate,

about 2 m m . long 0 3

2. Spikelets linear or linear oblong; scales loosely imbricate, usually

less than 2 mm. l o n g ...... „ o . 5

3(2). Achene elliptic-ovate, yellowish brown or purplish brown, not

more than two-thirds as long as the scales ...... , .

. . o ...... Cyperus niger var. castaneus

3. Achene obovate or obovate-oblong ...... 4

4(3). Spikelets 3-7 mm. long, 1.5-2 mm. wide, 5-16 flowered; scales

1 .5-1.8 mm. long, broadly ovate, greenish or yellowish; achene

obovate, about one half as long as the scale ......

...... Cyperus lanceolatus var. compositus

4. Spikelets 10-14 mm. long, 3 mm. wide, 20-24 flowered; scales ovate-

lanceolate, castaneus; achene subobovate-oblong, about two-

fifths as long as the scale...... Cyperus aschenbornianus 36

5(2). Spikelets borne in lax spikes; scales with broad, white hyaline

margins, the nerves 5; achene obovate, 1.2-1.5 mm. long, 0.6-

1 mm. wide, black, nearly equalling the subtending scales;

annual plant ...... Cyperus albomarginatus

5. Spikelets borne in glomerules; scales with thin, but scarcely white-

margined, the nerves 3; achene obovate-oblong, 0.8-1 mm. long,

0.4 mm. wide, brown to black, much shorter than the subtending

scales; perennial plant. Cyperus polystachyos var. leptostachyos

6(1). Rachilla of the spikelet persistent: Sub-genus Eucyperus. . . . 7

6. Rachilla of the spikelet deciduous: Sub-genus Mariscus ..... 11

7(6). Spikelets arranged in elongate spikes, these cylindrfc, 3-6 cm.

long, 1.5-2 mm. wide, the rachilla broadly winged; achenes one-

half to three-fifths as long as the glumes . . Cyperus digitatus

7. Spikelets arranged in a very short rachis, never in elongate spikes.

8

8(7). Spikelets crowded in a single dense head...... 9

8 . Spikelets not in a single head ...... 10

9(8). Scales mucronate, pale stramineus or fulvous, 3-nerved; bracts 3;

achene one-third as long as the glume... . .Cyperus seslerioides

9. Scales muticous, dirty-white, 5-nerved; bracts 6-8; achene two-

thirds as long as the glume...... Cyperus tenerrimus

10(8). Culms leafless; flowers dioecious; stamens 3; achene about one-

fourth as long as the glumes, trigonous-ellipsoidal......

...... Cyperus canus

10. Culms leafy below; flowers perfect; stamen 1, achene one-half as

long as the glume, elliptic-oblong .... .Cyperus surinamensis 37

11(6). Rachilla wings none, or if present, then not more than 0.2 mm.

wide, flat and not clasping the achenes. . . Cyperus spectabilis

11o Rachilla wings conspicuously developed ...... 12

12(11)o Scales not closely appressed (or at least the apex not ap~

pressed), tridentate at the apex, the sides white-hyaline to

yellow; culm slender, smooth, often tuberous thickened at the

base o ...... ooo.o.oooo..... Cyperus botteri

12. Scales closely appressed for their whole length; achene half as

long as to nearly equalling the scales; spikelets 1-5 flowered,

or sometimes (in Cyperus hermaphroditus), 7 flowered * . . . 13

13(12). Leaves 2-3 to a culm; leaves and bracts more or less scabrous;

spikelets ellipsoid, 3-5 mm. long, the rachilla zigzag; culm

base very thickened. s • .Cyperus mutissil

13. Leaves 3-9 to a culm; leaves and bracts glabrous, or obscurely

scabrous on the margins and midnerve; spikelets not ellipsoid,

more than 5 mm. long, rachilla straight; culm base slightly

thickened» . . • . • ...... „ . » ...... 14

14(13). Rays of the inflorescence about 10 cm. long; spikelets linear

lanceolate, 6-10 mm. long, 1 mm. wide; scale yellowish to

golden-brown...... Cyperus hermaphroditus

14. Rays of the inflorescence about 20 cm. long; spikelets cylindric,

about 4 cm. long, 1% cm. wide, base often branched; scale

reddish...... Cyperus hermaphroditus var. longespicatus

3. Eleocharis

1. Style 2-cleft; sheaths firm, with pointed tip; spikelets narrowly

ovoid, 2-4 mm. long; achenes lens-shaped, blackish, shiny at 38

maturity; plants annual,, densely tufted with fibrous roots,

tubercle depressed conic, constricted at base. o e .

• o * • o o o . o o . * * e <, o . Eleocharis atropurpurea

1 o Style 3-cleft; sheaths truncate, or only slightly oblique and weakly

mucronate at apex; spikelets ovoid to ellipsoid, 4 mm. long or

more; achene triangular in section ...... o » . 2

2(1). Perennial plants with creeping rootstocks; style base conical;

spikelets 24-70 flowered; bristles 4-6, dark reddish-brown,

equalling or slightly shorter than the achenes, minutely

toothed or barbed...... Eleocharis montevidensis

2. Annual tufted plants; style base pyramidal; spikelets 20-30 flowered

flowered; bristles 2 or 3, rarely persistent, light brown, less

than half as long as the achenes ...... Eleocharis capitata

4. Fimbristylis

One species...... Fimbristylis annua

5. Fuirena

One species...... Fuirena simplex

6 . Hemicarpha

One species Hemicarpha micranta

7. Scirpus

One species...... Scirpus americapua

5 . PALMAE. Palm Family

1. Perianth segments valvate in bud; style or stigma terminal in fruit;

seed globose to elliptic in shape, not depressed; leaf blade not 39

deflexed, the petiole with dentate or denticulate margin;

branches of the inflorescence at least the primary ones sub­

tended by spathes. . . *1. Erythea p. 39

1 o Perianth segments imbricate in bud; style or stigma basilar in

fruit; seed depressed globose; leaf blade deflexed along sub­

tended costa of petiole, this central margined . .2. Sabal p. 39

1 o Erythea

One species. . * . . . . . , « « . • . ..• . » . . . » .Erythea aculeata

2 o Sabal

One species. . « ...... Sabal uresana

6 . BROMELIACEAEo Pineapple Family

1. Leaves entire; seeds plumosely appendaged at base; flowers always

perfect; epiphytic plants. e ...... 3* Tillandsia p. 40

1. Leaves often spinose serrate; seeds with entire appendages, hot

plumose; flowers perfect or not; terrestrial plants...... 2

2(1). Flowers perfect, large and showy, the sepals about 20 mm. long;

anthers linear ...... 2. Pitcairnia p» 39

2. Flowers functionally dioecious, inconspicuous, up to 15 mm. long,

the sepals not more than 5 mm. long, squamiform; anthers

usually ovate. . 1. Hechtia p. 39

1. Hechtia

One species. ^ . Hechtia sp.

2. Pitcairnia

One species...... Pitcairnia palmeri 40

3 e Tillandsia

1 o Stamens and pistil exserted; leaves about 55 cm, long, the blades

flat, 4 cm, wide; sepals broadly elliptic, 25-30 mm, long;

petals purple, white margined, about 4 cm, long; inflorescence

compound; plants of shady side of cliffs in Oak Forest and

Short-tree Forest; epiphytic on Quercus albocincta; 2000-

5000 feet elevation, . . . . * ...... Tillandsia inf lata

1, Stamens deeply included, exceeding the pistil; leaves 3-17 cm, v

long, the blades terete, linear, 0.5-2 mm. in diameter; sepals

i lanceolate, 4-9 mm, long; inflorescence simple; epiphytic on

trees and shrubs in Thorn, Short-tree and Oak Forest; 1000-

3500 feet elevation. , Tillandsia recurvata

7. COMMELINACEAE. Spiderwort Family

1. Ultimate branches of the inflorescence composed of individual

scorpioid cymes, these appearing 1-sided superficially; flowers

zygomorphic...... o., . , . . o . 2

1. Ultimate branches of the inflorescence composed of paired sessile

scorpioid cymes, these appearing as 2-sided unit superficially;

flowers actinomorphic...... 3

2(1). Inflorescence subtended by a conspicuous compressed spathiform

bract; perfect stamens 3, 2 or 3 others usually present, but

with sterile cruciate-quadrifid anthers, the filaments long,

slender, glabrous...... 2 . Commelina p. 41 41

2• Inflorescence never subtended by a compressed spathiform bract;

stamens 6, all fertile, three of the filaments longer, naked

above, the three shorter ones barbate at the middle, , « , , , »

...... o e , , o o o . . o . o o , o . 3. Tinaiitia p. 41

3(1). Stamens 6, all fertile, the filamentsbearded below; leaves

linear, linear-lanceolate to elliptic-lanceolate; flowers

umbellate* . . 4. Tradescantia p, 42

3. Stamens 1-2, the filaments glabrous; leaves ovate or ovate-lanceo­

late; flowers in axillary glomerules * . * , . 1. Callisia p, 41

1. Callisia

One species, ...... Callisia monandra

2 o Commelina

1. Spathes open across the top and down adaxial side to spathe stalk,

long peduncled, 4-7,5 cm* long, the margins free; leaves linear,

finely pubescent to glabrous, to 15 cm, long, the sheaths 1,5-

2 cm, long; all three petals blue, the anterior slightly smaller

and ovate; stem erect, not rooting at the nodes, . » , , . - - ,

...... Commelina elegans

3. Tinantia

1 o Peduncles conspicuously glandular-villous, sub-umbellate or 2-fid at

the apex, 3-20 flowered; stems usually glabrous, except for a

line of puberulence on one side; leaves with scattered hairs on

both surfaces, deep green above, paler beneath, usually finely

pubescent beneath along the costa; sepals pubescent,

...... o , , T inant ia erecta 42

1» Peduncles glabrous5 sub-umbellate or corymbiform, sparsely 5-7

flowered; stems sparsely or densely villous in the upper half5

puberulent below; leaves bright green on both surfaces, densely

and finely puberulent, especially on the upper surface; sepals

glabrous . . „ * ...... » o . , . .Tinantia leiocalyx

4e Tradescantia

1 „ Flowers included in the swollen leaf sheaths; leaf blades lance-

ligulate to oblong-spathulate, 2-5 cm» wide, acute at apex,

finely puberulent on both surfaces, frequently moderately invo­

lute, slightly falcately curved downward • Tradescantia semisoma

1» Flowers well exserted, not included in swollen leaf sheaths; leaf

blades without the characteristic above...... 2

2(1)o Umbels entirely sessile, usually terminal, or if lateral inflo­

rescence is present at the upper nodes, the uppermost sessile

or subsessile and the successively lower with increasingly

evident peduncles...... 3

2. Umbels peduncled ...... 4

3(2). Leaves ovate-oblong, 1.5-2 cm. long; sepals oblong, navicular,

about 6 mm. long; petals broadly ovate, 6-7 mm. long; ovary

glabrous; mature capsule about 3 mm. long. . .

...... Tradescantia brachyphylla

3. Leaves linear-lanceolate, 1-10 cm. long; sepals elliptic, acute to

acuminate, 4-6 mm. long; petals ovate 9-12 mm. long; ovary

minutely glandular-puberulent; mature capsule 3-4 mm. long . . »

0 ...... Tradescantia pinetorum 43

4(2). Leaves linear, 15-30 cm. long, 3-4 mm. wide ...... 0

... o ...... Tradescantia rhodanthera

4. - Leaves not linear, usually shorter and wider than the last . .... 5

5(4). Leaves narrowly oblong or linear-oblong, usually 8-12.5 cm. long;

petal white or bluish, about 8 mm. long; seeds about 1.2 mm. in

diameter ...... Tradescantia chihuahuensis

5. . Leaves shaped not as above, 8 cm. long or less; petals lilac, pink

or purple; seeds about 1.5 mm. in diameter » ...... 6

6(5). Leaves cordate at the base and amplexicaul; stamens unequal with

three longer filaments dilated upward, sparsely barbate below;

ovary sparsely pubescent at apex; seeds brown......

o ...... Tradescantia amplexicaulis

6 . Leaves not cordate at the base; stamens unequal, longer filaments

naked, the three shorter ones densely barbate at the apex; seeds

gray-brown ...... Tradescantia disgrega

8. PONTEDERIACEAE. Pickerel-Weed Family • i 1. Heteranthera

One species...... Heteranthera limosa

9. JUNCACEAE. Rush Family

1. Juncus

One species...... Juncus macer

10 . LILIACEAE. Lily Family

1. Plants with a large woody caudex, often arborescent; leaves in large

rosettes at apex, or of its branches, stiff and swordlike. the margins usually filiferous or strongly serrate, often very

rigid and spine-tipped . „ * . „ * , . . . „ „ 2

1 o Plants herbaceous, without a woody caudex; stems from bulbs or

corms; leaves not stiff, filiferous, nor dentate-marginede . . 4

2(1)o Leaf margin filiferous, spine-tipped, elongate-linear to linear-

lanceolate; flowers seldom less than 2 cm. long, all perfect;

capsule 3-celled; seeds numerous in each cell, flattened . . . .

• . . o e » . o o o • . o o o ...... 9o Yucca p. 46

2. Leaf margin not filiferous, linear; flowers much less than 1 cm®

long, all or some of them unisexual; capsule 1- or 3-celled;

seeds solitary in each cell of the capsule

3(2). Leaves not very rigid, the margins usually serrulate; plants in­

completely dioecious, some of the flowers perfect; capsule

3-celled; seeds globose...... 7. Nolina p. 46

3. Leaves very rigid, the margins armed with sharp, curved spines;

plants completely dioecious; capsule 1-celled; seeds globose . .

...... o o ...... o ...... 4. Dasylirion p® 46

4(1). Plants with leafy stems; perianth of dissimilar segments, the

three outer narrow, the broader three bearing a conspicuous

glandular spot near the base; fruit a septicidal capsule . . . ®

...... 3.. Calochortus p® 46

4. Plant scapose or nearly so ...... 5

5 (4). Flowers in umbels or subumbellate clusters...... » . . . 6

5 . Flowers solitary or racemose, not in umbels...... 7 45

6(5). Perianth segments distinct, these less than 1 cm* long; umbels

few to many flowered; ovules two in each cell of the ovary;

plants with odor of onions * * . * . * . . . ® . 1. Allium p. 45

6 . Perianth segments united below into a salverform, tube; segments of

the perianth about 2 cm. long; umbels 2 or 3™flowered only;

ovules several in each cell of the ovary; plants without an

onion odor . * * * . . « . * * * . .6 . Mi 11a p® 46

7(5). Plants with bulbs; perianth segments each often with a gland near

the base, or not . . . * „ * * „ . * , * ...... 8

7. Plants never with bulbs; perianth segments without glands*.« . » 10

8(7). Flowers solitary; perianth segments not glandular within. . . * .

...... 6 . Mi 11a p. 46

8 * Flowers numerous; perianth segments with gland within* * * * . . . 9

9(8). Flowers spicate; perianth segments essentially free; plants of

5000-6000 feet elevation...... 8. Schoenocaulon p * 46

9* Flowers racemose; perianth segments sometimes connate at the base;

plants of 8000 feet elevation * 10* Zygadenus p * 46

10(7). Anthers linear, coherent about the style to form a cylinder* . .

...... * ...... *5* Echeandia p. 46

10* Anthers linear-oblong; free * ...... 2. Anthericum p* 45

1* Allium

One species, ...... * . . -Allium kunthii

2. Anther icum

One species. .***<, ...... Anther icum torreyi 46

3» Calochortus (102)

1 e Flowers nodding; sepals shorter than the petals; glands - present and

conspicuous on both sepals and petals. . . . «,Calochortus fuscus

I. Flowers erect; sepals equalling the petals; glands inconspicuous or

absent . . . . * . , . * . * ...... Calochortus venustulus

4. Dasylirion

One species...... a.. ... -o • Dasylirion wheeleri.

5. Echeand ia

One species. . . . . , ...... „ ...... Echeandia brevifolia

6 o Milla

One species. „ . . . . , ...... Milla biflora

7. Nolina

1. Plants caulescent, 3-8 m. high; leaves 10-15 mm. wide at base;

primary branches of the inflorescence 15-35 cm. long; pedicels

8-10 mm. long, usually longer than the capsules, these charta-

ceous, stiff ...... o o o ...... Molina matapensis

1. Plants acaulescent; leaves 6-12 mm. wide at base; primary branches

of the inflorescence 15-50 cm. long; pedicels 4-5 mm. long,

about equalling or slightly shorter than the capsules, these

papery, delicate ...... Nolina microcarpa

8 . Schoenocaulon

One species...... Schoenocaulon drummondii

9. Yucca .

One species......

10. Zygadenus

One species. . . . . 11. AMARYLL ID AC EAE „ Amaryllis Family

1. Perennial plants by bulbs; leaves and scapes ephemeral; segments of

perianth narrowly linear9 1*5-2 mm. wide; filaments connected

into a fragile tube at base* ••••••• 2. Hymenocallis p. 49

1 * Perennial plants by corm or rootstock. *

2 (1). Flowers few, about 2, subumbellate; segments of the perianth

pubescent on outside; leaves narrow, grasslike, not fleshy;

scapes slender, sparsely villous; herbaceous plant with a corm

base ...... 3. :Hypoxis p. 49

2. Flowers numerous, spicate, racemose or paniculate* * • 0 •'•••• 3

3(2). Leaf blades spine-tipped and often spiny-margined; inflorescence

a dense spike, raceme or p a n i c l e...... 1 * Agave p. 47

3. Leaf-blades neither spine-tipped norspiny-margined; inflorescence

of lax spikes or racemes * . 4. Manfreda p * 49

1 o Agave (32)

1. Inflorescence spicate or racemose * . . * * , * , * * . * . . . . * 2

1. Inflorescence paniculate; flowers in umbellateclusters on lateral

b r an che s . . . . * * * @ . © © . © © * * . * * . . * . . . . , 3

2(1). Leaves filiferous, 10-20 cm. long, 1-1.3 cm. wide; flowers

pruinose pink, the tube about 25-30 mm. long, very narrow and

curved b e l o w ...... *.. 4-Agave polianthifolia

2. Leaves not filiferous, larger, 1-2 m. long, 7-10 cm. wide; flowers

yellow, the tube about 4 mm. long, shallow and open. ••••••

. *Agave vilmoriniana 48

3(1)• Leaves sword-shaped/ usually 50-120 cm. long, 4-8 cm. wide, rigid

and straight to falcate; teeth always present, usually dark

brownish to black, the cusps flexed upward; tepals withered and

sharply reflexed in post-anthesis...... *Agave pacifica

3. Leaves rarely sword-shaped, usually less than 10 times longer than

wide, variously curved, if rigid,then short and broad, sometimes

toothless; tepals usually not withered and not sharply reflexed .

in post-anthesis...... > . . 4

4(3). Non-suckering rosettes; leaves yellowish green to green, broadly

lanceolate to spathulate, about 4 times as long as wide, much

narrowed towards base; panicles 5-7 m. tall, narrow and deep

with 20-30 short laterals...... Agave bovicornuta

4. Rosettes suckering, soon or late; leaves mostly glaucous gray, but

sometimes green, linear to broadly lanceolate; panicles less

narrow and shorter, laterals usually less.than 20...... 5

5(4). Rosettes green, medium to large; tepals dimorphic, 15-23 mm.

long, about equalling the tube, this deeply funnelform, 18-22

mm. long; panicle about 5 m. tall...... Agave wocomahi

5. Rosettes glaucous gray, small to medium; tepals usually shorter than

the tube; panicles less than 5 m. tall ...... 6

6(5). Rosettes suckering with maturity; leaves ovate, uniformly gray;

panicles 2 .5-5 m. tall with 8-16 distal ascending laterals in

upper third...... *Agave shrevei subsp. shrevei

6 . Rosettes suckering while young; leaves ovate, but frequently cross­

zoned and red-tinted; panicles 2-3 m. tall with densely flowered

"laterals in upper half or two-thirds...... Agave colorata 49

2, Hymenocallis

One s p e c i e s Hymenocallis sonorensis

3o Hypoxis

One specieso ...... Hypoxis decumbens

4 . Manfreda (126)

1 e Flower tube longer than the perianth parts, curved; filaments

shortly exserted, usually 5-10 mm, beyond perianth parts;

leaves 20-30 cm, long, 7-10 mm. wide . . . Manfreda singuliflora

1. Flower tube shorter than the perianth parts, straight; filaments

long exserted, usually 50-60 mm. beyond perianth parts; leaves -

40-60 cm. long, about 10 mm, wide Manfreda jaliscana

12. DIOSCOREACEAEo Yam Family

1. Dioscorea

One species...... Dioscorea convolvulacea var . grandifolia

13. IRIDACEAEo Iris Family

1. Flowering stems from a short rootstock or from a cluster of fibrous

roots; filaments united into a tube and around the style; sepals

and petals mucronate or cristate at the apex ...... »

...... 2 . Sisyrinchium p. 50

1 o Flowering stems from a bulb-like corm, usually covered with

membranaceous tunics ...... » ...... 2

2(1). Perianth parts similar; style 3-branched, the branches bifid. . .

...... 1. Nemastylis p. 50

2. Perianth parts dissimilar; outer segments with a large spreading

ovate scarlet limb an inch broad, and a broad claw spotted all 50

over, inner segments with as large a claw and very small ovate

acute limb , ...... 3. Tigridia po 50

1« Nemastylis

One species. o « o . . o ...... „ Nemastylis pringlei

2. Sisyrinchium

1 e Stems broadly winged throughout; perianth orange, the segments 15

mm. or longer; filaments slightly connate at the base only;

capsule oblong «, . * ...... Sisyrinchium arizonicum

1. Stems flattened and narrowly winged upward; perianth usually lilac

with a yellow base, the segments less than 15 mm. long; fila- .

ments united nearly to the top in a cylindrical column;

capsule globose...... Sisyrinchium scabrum

3 . Tigridia

One species...... Tigridia pringlei

14. ORCHIDACEAE. Orchis Family (164)

1. Caudicle and gland arising from the base of the pollinia; anthers

erect or more of less resupinate, the broad base very closely

adnate to the column, never deciduous after flowering; pollinia

always glandular ...... 3. Habenaria p. 52

1 o Caudicle and gland arising from the apex of the pollinia; anthers

erect or incumbent, the filament short and slender, generally

narrowly jointed to the column, usually deciduous, but if per­

sisting, soon withering...... 2

2 (1). Pollinia glandular, soft; anthers commonly persisting, but with­

ering; inflorescence terminal8. . Spiranthes p. 54 51

2 e Pollinia waxy or cartilaginous; anthers commonly soon deciduous;

inflorescence terminal or lateral...... * * 3

3(2). Inflorescence normally terminal, or by abortion of the terminal

inflorescence axillary in the upper leaves ...... * 4

3. Inflorescence lateral, arising near the base of the pseudo-bulbs or

in the axils of the leaves or sheaths...... 6

4(3). Pollinia without appendages, i . e. no viscid disk or caudicles

present; column very short, 1 mm. long or less .6 . Malaxis p; 53

4. Pollinia appendages, i. e . with at least rudimentary viscid disk,

or a caudicle having a viscid apex; column usually longer than

1 mm .. o . . . . c o . « . . . O • e ...... ® 5

5(4). Pollinia four, two in each anther-cell; flowers usually not large

and showy...... 2. Ep id end rum p. 52

5. Pollinia eight, four in each anther-cell; flowers usually large and

showy. . .5. Paella p. 53

6(3). Pollinia with a prominent stipe, although sometimes short; viscid

disk distinct...... 7. Oncidium p. 53

6 . Pollinia without a stipe; viscid disk commonly rudimentary, or the

apex of the caudicle glutinous ...... 7

7(6). Plants saprophytic, without true leaves; rhizome coralloid; stem

elongate ...... 4. Hexalectris p. 53

7. Plants not saprophytic, with green leaves; roots not coralloid; stem

shortened or pseudobulbous ...... 1 . Bletia p. 51

1. Bletia

1. Leaves 1-2, less than five times longer than broad; apical lobe

’of the lip usually as broad as the basal lobes, the disk 52

papiliferous along the nerves up to the base of the middle

lobe, the papillae purplisho . . „ *Bletia gracilis var. zoezlii

lo Leaves 2-several, usually more than five times longer than broad;

apical lobe of the lip usually narrower than the basal lobes,

the disk provided with 5 parallel lamellae, the 2-3 central

lamellae conspicuously raised about the middle of the lip and

on the midlobe . * . . . . , ...... *Bletia reflexa

2. Epidendrum

One species o...... ,Epidendrum microbulbon

3. Habenaria

1« Spur 3.5 cm. long or more, much longer than the pedicellate ovary;

lateral lobes of lip 1.5 ciru long or more .^Habenaria quinqueseta

1. Spur less than 3.5 cm. long, about as long as the pedicellate ovary;

lateral lobes of lip less than 1.5 cm. long. . \ . . .* . . . . 2

2(1). Flowers white; mid-lobe of lip conspicuously wider than the

lateral lobes, sub-equal in length . . . . . *Habenaria clypeata

2. Flowers green or yellowish green; mid-lobe of lip not conspicuously

wider than the lateral lobes, usually unequal in length. . . . 3

3(2). Flowers relatively large; lateral sepals 4-6 mm. wide; leaves

lanceolate or the lower ovate, acute, 7.5 cm. long or less;

column with fleshy oblong appendages at base, short, 2-3 mm.

l o n g ...... Habenaria jaliscana

3 o Flowers relatively small; lateral sepals usually less than 4 mnu

wide; leaves oblong-elliptic to linear-lonceolate, acute or

acuminate, spreading, 3-14 cm. long; column much longer, 2.5-3

cm. long ...... Habenaria novemfida 53

4. Hexalectris

One species o e • . ,^He-xalectris Rrandiflora

5 o Laelia

One species o ‘.o. Laelia autumnalis

6 . Malaxis

1, Inflorescence subumbellate or corymbose* » e 0 * * « o * 2

1. Inflorescence spicate or racemose* . • • ...... * . 4

2(1). Lip not tridentate or trilobulate at the apex, usually without

distinct basal auricles, cucullate-cymbiform, with a distinct

median carina within the concave-saccate portion; bifoliate«, ». .

. , o . . * . . * ...... Malaxis fastigiata

2 c Lip tridentate or trilobulate at apex ...... 3

3.(2). Lip with the central tooth or lobule minute, apiculate; flowers

minute on filiform pedicels 3-10 mm. long; sepals 1-nerved, the

margins somewhat involute; petals narrowly linear to filiform;

unifoliate . 0 . . . o . -Malaxis unifolia

3* Lip with the central tooth or lobule much larger than the lateral

lobes; flowers on slender pedicels, but 12-18 mm, long; sepals

3-nerved, the margins strongly revolute; petals filiform; bi­

foliate...... ooocoe.ee* .Malaxis fastigiata

4(1). Unifoliate; apex of the lip retuse or notched; pedicel at least

twice as long as the flowers -Malaxis uni folia

4* Bifoliate; apex of the lip not retuse or notched; pedicel 3-4 or

more times longer than the flowers . .. * • . .Malaxis fastigiata

7. Qncidium

One species -Qncidium longifolium 54

8 » Spiranthes

1 . Flowers orange-colored to orange-red; floral bracts linear-oblong

to oblong-lanceolate, acute, 3-6 cm. long, 1-1.5 cm. wide;

leaves more or less scattered on the stem, usually present

at time of flowering . * <> ...... -Spiranthes aurantiaca

1 o Flowers pale greenish; floral bracts triangular-lanceolate,

acuminate, longitudinally concave, up to 3 cm. long, narrower

than the species above; leaves absent at time of flowering,

when, present, elliptic and petiolate from the base of the plant.

0 o . a o ..... o . . o ...... ^Spiranthes pauciflora Sub-class II. DICOTYLEDONEAE

Key to the Series of the Dicotyledoneae

1. Petals none; perianth segments all much alike in texture and color,

or represented by a bract, or none » . .SERIES I. APETALAE po 55 . lc Petals present; outer segments (calyx) and inner segments (corolla)

usually markedly different in texture or color, or in both

characters ...... 2

2(1). Petals distinct, free from one another, at least at the base and

usually the full length...... SERIES II. CHORIPETALAE p. 61

2. Petals united into a tube or cup, at least at the base, and usually

for much of their length, the corolla lobes either shorter or

longer than the tube ...... SERIES III. SYMPETALAE p® 71

SERIES I 0 APETALAE

Key to the Families:

1. Flowers (either staminate or pistillate or both sexes) in catkin­

like inflorescence o..o*..o.o...o..o. . . . . 2

1. Flowers not in catkins ...... 9

2(1). Seeds bearing a tuft of long, silky hairs; fruit a small capsule.

...... 1. SALICACEAE p. 80

2. Seeds not bearing silky hairs; fruit not a capsule ...... 3

3(2). Pistillate and usually staminate flowers both in catkins. . . . 4

3. Pistillate flowers solitary or in few-flowered clusters; staminate

flowers in cat k i n s...... 7

55 56

4(3)« Plants monoecious, the flowers usually subtended by conspicuous

bracts .0 . . 5

4 o Plants dioecious, or if monoecious, the flowers not conspicuously

bracted. . . „ . . . . . » . . . * ...... e . 6

5(4) o Ovary 1-celled, 1-ovulate; style 1. * . . . . 2. PIPERACEAE p» 80

5 ® Ovary 2-celled, 2-ovulate; styles 2« ...... 4 * BETULACEAE p«, 80

6(4). Carpels numerous and fused into a compound, fleshy fruit, or dry

and subtended by conspicuous papery bracts; leaves thin. ... . «

o <» o o o o o ...... 6 0 0 o ... 7. MORACEAE p. 82

6. Carpels remaining distinct, not subtended by a conspicuous papery

bract; leaves thick: Genus Garrya...... 74. CORNACEAE p. 172

7(3). Stinging hairs arming the stems and leaves; fruit an achene . . .

...... 8. URTICACEAE p . 83

7. Stinging hairs none; fruit a nut or an acorn ...... 8

8(7). Fruit a hard-shelled nut with leathery covering, not set in an

involucre; cotyledons 2-lobed; leaves pinnately compound ....

...... o .... 3. JUGLANDACEAE p. 80

8. Fruit a thin-shelled acorn, the base set in a cup-like involucre;

cotyledons entire; leaves simple though sometimes deeply lobed .

...... o o ...... o ..... 5. FAGACEAE p. 80

9(1). Flowers inserted inside a hollow globose or ovoid fleshy recep­

tacle; stipules calyptralike over the terminal buds, caducous:

Genus Ficus ...... 7. MORACEAE p. 82

9. Flowers variously arranged, but not inside a fleshy receptacle;

stipules not calyptralike...... 10 57

10(9)o Ovary inferior, adnata to the calyx if the latter is present . »

. 11

10. Ovary superior, free from the calyx if present...... 15

11(10). Perianth really double, but appearing single and corolla-like;

calyx with tube wholly adnate to the ovary and the limb obsolete

or reduced to a mere border or teeth: families belonging mainly

to Series CHORIPETALAE and SYMPETALAE...... 12.

11. Perianth in 1 series, calyx-like or corolla-like ...... 14

12(11). Fruit an achene, not paired ...... 108. COMPOSITAE p. 225

12. Fruit a pair of contiguous 1-seeded carpels ...... 13

13(12). Flowers in umbels or heads, rarely spikes; leaves alternate or

basal, mostly compound ...... 73. UMBELLIFERAE p. 170

13. Flowers in cymes or solitary in the axils; leaves appearing

whorled, simple: Genus Galium...... 104. RUBIACEAE p. 217

14(11). Plants parasitic on stems or branches of shrubs and trees;

fruit a berry...... 9. LORANTHACEAE p. 84

14. Plants terrestrial, autophytic or (exceptionally) root parasitic;

fruit a capsule...... 11. ARISTOLOCHIACEAE p. 85

15(10). Pistils usually more than one in each flower; fruit a laterally

compressed or angled achene...... 16

15. Pistil one in each; flower, simple or compound; fruit various. . .17

16(15). Herbaceous or suffrutescent plants; flowers mostly perfect,

rarely dioecious, not in heads; stipules none; achenes later­

ally compressed: Genera Thalictrum and Clematis......

...... 21. RANUNCULACEAE p. 95 58

16» Large trees; flowers monoecious in globose heads, racemosely

arranged on a slender axis; stipules present, caducous; achenes

3-4 angled ...... 29. PLATANACEAE p. 100

17 (15) . Ovary 1-celled. * ...... 18

17. Ovary 2-celled to several-celled (exceptionally 1-celled by

abortion)...... » .32

18(17). Stamens distinctly perigynous: Genus Alchemilla . » •■« . . .

...... o . o o ...... o .. . . 30. ROSACEAE p. 100

18. Stamens hypogynous. • <> . ... • . . . . . » « . . «, ...... 19

19(18). Shrubs or trees ...... 20

19. Herbaceous or suffrutescent plants...... 26

20(19). Ovules several to many...... 61. FIACOURTIACEAE p. 160

20. Ovule 1 ..... o . o ..... 6 . o e o ...... 21

21(20). Stipules present...... a ...... 22

21. Stipules none ...... • ...... • • ...... 24

22(21). Stinging hairs often present; fruit an achene: Genus Urera. . »

c o ...... 8. URTICACEAE p. 83

22. Stinging hairs none; fruit a drupe...... 23

23(22). Leaf blades asymmetrical at base, very scabrous above; stigmas

2...... 6. ULMACEAE p. 82

23. Leaf blades symmetrical at base, not scabrous; stigma 1 .... .= .

...... 10. OPILIACEAE p. 85

24(21)o Branches armed with numerous stout spines: Genus Pisonia. . •.•

. . . . 15. NYCTAGINACEAE p. 90

24. Branches unarmed...... o ...... 25 59

25(24). Stamens 5 or fewer; fruit an utricle; plants not aromatic . „ .

...... 14. AMARANTHACEAE p. 88

25. Stamens usually more than 5, mostly 9-12; plants aromatic . . . . .

...... 23. LAURACEAE p. 96

26(19). Style and (or) stigma 1 ...... 27

26. Style and (or) stigmas 2 or more...... 29

27(26). Ovary technically superior but in fruit very closely enveloped .

by the perianth tube and appearing inferior......

...... 15. NYCTAGINACEAE p. 90

27. Ovary not appearing inferior...... 28

28(27). Perianth segments and stamens 4; floral bracts not scarious or

hyaline: Genus Rivina...... 16. PHYTOLACCACEAE p. 92

28. Perianth segments generally 5; stamens usually 5 or fewer; floral

bracts hyaline, scarious . . . . * . . .14. AMARANTHACEAE p. 88

29(26) . Fruit circumscissile...... 14. AMARANTHACEAE p. 88

29. Fruit not circumscissile...... „ .30

30(29). Stipules present, frequently sheathing (except in Eriogonum) ;

achenes mostly trigonous; sepals usually 6 in 2 whorls . . . . .

...... 12. POLYGONACEAE p. 86

30. Stipules none; fruit lenticular, ovoid or globose; sepals not as

above...... 31

31(30). Bracts and sepals fleshy or herbaceous, not scarious; stamens

distinct at the base; leaves often scurfy......

...... 13. CHEN OP ODIACEAE p. 87

31. Bracts and sepals scarious; stamens connate at base; leaves not

"scurfy ...... 14. AMARANTHACEAE p. 88 60

32 (17) , Plants shrubby or arborescent . „ • « ...... * . . . o33

32. Plants herbaceous, or slightly suffrutescent...... 38

33(32) . Fruit a samara-, • ,34

33 o Fruit otherwise e •••••••••'.• o o..« o.. • .35

34(33). Leaves opposite, palmately lobed or divided; samaras in pairs,

usually glabrous; plants of Pine-Forest. . ,48, ACERACEAE p, 146

34. Leaves alternate, pinnate; samara not in pairs, pubescent; plants

of Short-tree Forest . . . . , . V . . .39. SIMAROUBACEAE p. 133

35(33). Fruit drupaceous...... ^36

35. Fruit a capsule ...... 37

36(35). Flowers dioecious; stamens numerous, much more than 5; leaves

simple, sometimes 3-foliolate: Genus Forchammeria......

.26. CAPPAR1DACEAE p. 98

36. Flowers perfect or polygamodioecious; stamens 4 or 5; leaves always

simple: Genera Condalia and Rhamnus. . . .50. RHAMNACEAE p. 147

37(35). Capsule not winged; leaves not viscid, entire to palmately

parted; embryo straight or curved, not spirally coiled . . . . .

...... 44. EUPHORBIACEAE p. 137

37. Capsule conspicuously winged; leaves somewhat viscid, narrow,

entire; embryo spirally coiled: Genus Dodonaea ......

.... o o ...... 49. SAPINDACEAE p. 146

38(32). Fruit depressed-globose, several-seeded berry; a coarse some­

what succulent herb, usually with large leaves: Genus Phytolacca

...... 16. PHYTOLACCACEAE p . 92

38 o Fruit otherwise ...... 39 61

39(38). Fruit a silicle, compressed contrary to the partition; stamens

2, 4 or 6: Genus Lepidium * , . 25. CRUCIFERAE p. 97

39 o Fruit a capsule, not compressed contrary to the partition; stamens

variable in number . „ . * „ » * ...... » « » . e « » *40

40(39). Flowers unisexual, often enclosed in a calyx-1ike involucre *

or borne on axillary bracts...... 44. EUPHORBIACEAE p» 137

40. Flowers perfect, not in an involucre nor on axillary bracts . * *

...... 17. AIZOACEAE p. 97

SERIES II. CHORIPETALAE

Key to the Families:

1. Ovary inferior, at least the lower part distinctly adnate to the

calyx tube or hypanthium . . . . * ...... * * ***** . * 2

1. Ovary superior, free from the calyx or adnate to it only slightly

at base...... o*...**o*.**«**.*.* *14

2(1). Aquatic herbs with submerged rhizomes . . 19. NYMPHAEACEAE p. 93

2. Habitat not as a b o v e ...... **.*. 3

3(2). Stems very thick and succulent, flat or cylindric, with spines,

or barbed bristles or both, these borne on cushion-like areoles^

leaves none, or greatly reduced and terete; sepals and petals

indefinite in number, not sharply differentiated ......

* . . .67. CACTACEAE p. 162

3.o Stems not succulent, or if so, then not areolate; leaves mostly

well developed; sepals and petals not indefinite in number,

usually differentiated...... * .' . * 4

4(3). Flowers in umbels or dense round heads, if in slender interrupted

spikes, then the leaves orbicular and peltate. 5 62

4. Flowers not in umbels or dense round heads, if the inflorescence

subcapitate, then the plant armed with stinging hairs e ...06

5(4). Ovary 5-celled; styles 5; fruit a berry or drupe» . . . . . * « .

...... 72. ARALIACEAE p. 170

5. Ovary 2-celled; styles 2; fruit a schizocarp of 2 one-seeded

mericarps...... 73. UMBELLIFERAE p. 170

6(4). Stamens numerous, usually over 10 in number ...... 7.

6. Stamens not more than 1 0 ...... o 9

7(6). Ovary 1-celled...... 65. LOASACEAE p. 161

7 o Ovary 2- or more-celled, ••-•••.••o.e... •••••. .8

8(7). Plants arborescent, up to 12-15 meters high; flowers perfect;

stamens about 100...... 70. MYRTACEAE p. 167

8. Plants herbaceous; flowers monoecious; stamens much less than 100. .

...... 66. BEGONIACEAE p. 162

9(6). Ovary 1-celled, rarely 2...... 8 .. . .10

9. Ovary 2- to 5-celled ...... o ... .12

10(9). Herbage very rough-pubescent, the hairs commonly barbed, some­

times stinging ...... 65. LOASACEAE p. 161

10. Herbage not rough-pubescent, or the hairs never barbed or

stinging ...... 11

11(10). Herbs with scapose stems; fruit a follicle......

...... 28. SAXIFRAGACEAE p. 100

11. Shrubs or trees with leafy stems; fruit a drupe: Genus Cornus . « .

. 0 „ o ...... 74. CORHACEAE p. 172

12(9). Stipules none; ovary 4-celled (2- to 3-celled in Gongylocarpus)

' . . 71. ONAGRACEAE p. 167 12'.. Stipules present; ovary 2- to 3-celled...... 0 . .IS'

13(12), Oyary 2-celled; fruit leathery or woody, tardily dehiscent or

indehiscent; petals not hooded . . . . 69, RHIZOPHOEACEAE p. 167

13* Ovary 3-celled; fruit separating into 3 indehiscent, narrowly

winged cocci; petals hooded and partially or wholly enclosing

the anthers: Genus Gouania * ...... 50* RHAMNA.CEAE p. 147

14 (1) , Flowers distinctly irregular...... 15

14. Flowers regular or nearly so. . * . . „ „ . * . . * ...... 25

15(14). Leaves compound * .... 0 o.. * . e...... 16

15. Leaves simple, sometimes palmately lobed or parted...... 18

16(15). Ovary usually 3-celled; fruit samaroid or capsular: Genera

Serjania and Cardiospermum ...... 49. SAPINDACEAE p . 146

16. Ovary unicarpelate and 1-celled; fruit a legume, dehiscent or less

commonly indehiscent ...... 17

17(16). Flowers only moderately irregular, the lower pari of petals

not connate; upper petal innermost in bud; Sub-family

Caesalpinioideae ...... 32. LEGUMINOSAE p. 102

17. Flowers markedly irregular, the lower pair of petals fused to form

a keel; upper petaloutermost in bud: Sub-family Papilionoideae.

...... 32. LEGIMINOSAE p. 102

18(15) . Fruit a legume...... *19

18. Fruit not a legume...... 20

19(18)* Anthers dehiscent longitudinally; stamens usually 10; 2 lower

petals adnate along the lower margin to form a boat-shaped keel:

Sub-family Papilionoideae...... 32. LEGIMINOSAE p . 102 64

19 e Anthers dehiscent by terminal pores; stamens 4; 2 lower petals

frees glandular9 upper three petals long-clawed* , .

31. KRAMERIACEAE p. 101

20(18). Fruit of 3-5 distinct follicles;, flowers showy, mostly blue or .

bluish, very irregular, the sepals larger and usually more

highly colored than the petals: Genus Delphinium...... » .

..op. 21. RANUNCULACEAE p. 95.

20. Fruit various, but not follicular . . . *21

21(20). Stamens many, usually more than 12. 59. COCHLOSPEEKACEAE p. 159

21. Stamens not more than 12...... o „ o . o o o . .22

22(21). Spur or saccate swelling present on either the sepal or petal .

...... * ...... 23

22. Spur or saccate swelling n o n e ...... 24

23(22). Sepals gamophyllus, asymmetric, and enlarged in fruit; petals

and stamens borne on the throat of the calyx; stamens usually

11: Genus Cuphea ...... 11. LYTHRACEAE p. 85

23. Sepals distinct or nearly so; petals and stamens free from the

calyx; stamens usually 5 ...... 60. VIOLAGEAE p. 159

24(22). Sepals all alike, usually bearing 2-several glands on outer

surface; anthers 2-celled; stamens 5 or 10......

42. MLPIGHIACEAE p. 134

24. Sepals of 2 kinds, the outer much smaller than inner, glandless;

anthers 1-celled, opening by terminal pores; stamens 3, 6 or 8,

mostly S.ooo...... 43. P0LYGALACEAE p. 136

25(14). Anthers opening by terminal po r e s ...... 26

25. Anthers opening longitudinally...... 29 65

26(25)o Leaves palmately lobed; stems usually from a large, tuber-like

root; stamens numerous „ „ 6 e . 59. COCHLOSPERMACEAE p. 159

26. Leaves not palmately lobed; stems not as above; stamens usually

not over 12. e ...... 27

27(26). Leaves reduced to scales; plants saprophytic, lacking chloro­

phyll: Genus Monotropa ...... 76. PYROLACEAE p. 173

27. Leaves with well developed blades; plants autotrophic and green .28

28(27). Plant a tree; leaves 6-15 cm. long, alternate; capsule about

4 mm. broad...... 75. CLETHRACEAE p. 173

28. Plant suffruticose; leaves 2-6 cm. long, tending to form whorls;

capsule about 8 mm. broad: Genus Chimaphylla ......

...... 76. PYROLACEAE p. 173

29(25). Flowers in dense globose heads, very numerous and minute; plant

a tree; leaves large, palmately lobed. . .29. PLATANACEAE p. 100

29o Flowers not in dense globose heads, or the plant not a tree with

palmately lobed leaves ...... o ...... 30

30(29). Stamens and petals inserted on a pronounced disk lining the

calyx cup, or on the upper edge of the calyx cup itself, hence

noticeable above the base of the ovary and more or less

perigynous ...... 31

30. Stamens and petals inserted on the receptacle or on a narrow disk

at the base of the pistil...... 42

31(30). Stems climbing or trailing, with tendrils, herbaceous or

suffrutescent; flowers relatively large; calyx throat bearing a

conspicuous, fringed corona...... 63.PASSIFLORACEAE p. 160 66

31• Stems not climbing or trailing or3 if so, then the flowers small

and the calyx throat not with a fringed corona ...... 32

32 (31) . Stamens over 15 . . o @ , 0 0 ....,, *33

32 o Stamens not over 1 5 ...... ®...... ®34

33(32). Fruit an achene; hypanthium usually persistent: Genera

Potentilla and Holodiscus. „ ...... 30. ROSACEAE p. 100

33. Fruit a drupe; hypanthium usually deciduous: Genus Prunus * . * » .

...... 30. ROSACEAE p. 100

34(32). Stamens as many as the petals and opposite them; petals either

hooded or caducous . . . ® * o'® . • . . ® . ® . . . . .35

34. Stamens as many as the petals and alternate with them, or twice as

many as the petals; petals not hooded or caducous. . 9 . . ® .36

35(34)0 Plants shrubby; petals hooded, each more or less enfolding the

adjacent stamen; tendrils none . .. » . . .50. RHAMNACEAE p . 147

35. Plants climbing vines; petals not hooded; tendrils present,

usually opposite the leaves: Genera Ampelocissus and Cissus . ®

...... 51. VTTACEAE p. 149

36(34). Leaves opposite or verticeHate ...... 37

36. Leaves alternate...... 38

37(36). Plants herbaceous; fruit readily dehiscent; calyx-tube often

with accessory appendages in the sinuses: Genus Rotala .....

...... 68. LYTHRACEAE p. 166

37. Plants shrubs or sometimes trees; fruit indehiscent; accessory

appendages none...... 69. RHIZOPHORACEAE p. 167

38(36). Ovary 1-celled...... 39

38. Ovary 2-celled...... 40 39 (38) • Fruit a drupe; ovule 1 in each cell . 45. .ANAGARDIACEAE p 0 145

39 o Fruit a capsule; ovules more than one in each cell» ,......

P- 160

40(38) e Leaves simple » » « . » . 146

40 o Leaves pinnately compound . 0 . « . « . . .41

41(40). Fruit a drupe: Genus Spondias . . . . .45. ANAGARDIACEAE p. 145

41o Fruit a berry: Genus Sapindus o ...... 49. SAPINDACEAE P° 146

42(30). Stamens more than 100 » . * „ * » .

42 o Stamens 10 or fewer . . . ■ . » o • "o „ o . 9 0 » e 9 . 9 a I .55

43(42). Pistils several and free; fruit achenes or follicles: Genera

Aquilegia and Ranunculus . . „ . . P* 95

43. Pistil 1 in each flower, of 1-several connate carpels; fruit

various...... 44

44(43) . . Ovary 1-celled...... = ° .45

44. Ovary 2-several-celled, or if 1-celled, then placentas 3. . .’ ° .49

45(44). Styles 2-8; sepals 2...... p. 93

45 o Style 1; sepals 3-5 ...... 46

46(45). Leaves simple, entire or dissected.

46. Leaves bipinnately compound: Sub-family 'Mimosoideae . . . . <- • . .

P- 102

47(46). Petals twice as many as the sepals; sepals caducous » . . . .

p. 97

47. Petals as many as the sepals; sepals persistent ...... 48

48(47). Sepals all alike: Genus Corchorus •. .. . .52. TILIACEAE p. 150

48. Sepals dissimilar, the outer 2 much smaller than the inner 3 . . * .

P- 159 68

49(44)e Stamens free, not fused into a column . • . ■ . 0 » • « . v •" .50

49o Stamens fused into a column, or connate at the base into blunders

or clusters o ...... o53

50(49). Sepals in two series, the outer.2 smaller than the inner 3. » .

...... o ...... 58. CISTACEAE p. 159

50. Sepals all alike or essentially so, in a single whorl ...... 51

51(50) . Leaves digitately compound. . 54. BOMBACACEAE p. 157.

51. Leaves simple, entire or lobed...... e ...... 52

52(51). Stipules present, persistent; fruit drupaceous...... « .

...... 52. TILIACEAE p. 150

52. Stipules none; fruit capsular ...... 56. GUTTIFERAE p. 158

53(49). Ovary 3-carpelled; leaves without stipules; style branches

usually branched: Genus Ditaxis. . . . .44. EUPHORBIACEAE p. 137

53. Ovary 5-or more carpelled; leaves stipulate; style branches simple

...... 54

54(53). Fruit a 5-carpelled, woody capsule to 15 cm. long; bark on old

trunks often bearing conical tubercles . .54. BOMBACACEAE p. 157

54. Carpels separating in fruit or, if capsular, then 5 cm. long or

less; bark not tuberculate ...... 53. MALVACEAE p. 151

55(42). Flowers dioecious, monoecious or polygamodioecious...... =56

55. Flowers perfect ...... ® . .62

56(55). Pistillate flowers apetalous; leaves stipulate; stamens 4 . . .

...... 10. OPILIACEAE p. 85

56. Pistillate flowers bearing 1 or more petals; leaves without

stipules; stamens 4-10 = .57 69

57 (56). Stamens connate into a tube, or their bases fused into a

shallow cup...... 41. MELIACEAE p. 134

57. Stamens free, not connate into a tube or cup...... 58

58(57). Sepals in two series, the inner whorl longer than the outer;

seeds reniform: Genus Cocculus .... 22. MENISPERJMACEAE p. 96

58. Sepals usually, alike in one series; seeds not reniform...... 59

59(58). Carpels 1-ovuled...... 60

59. Carpels 2-ovuled...... 61

60(59) . Style none or, if present, only 1 and short and thick ......

.... o ...... 46. AQUIFOLIACEAE p. 146

60. Styles present, 3-5 ...... 45. ANACAKD1ACEAE p. 145

61(59). Fruit follicular; branches spinescent: Genus Zanthoxylum. . » .

...... 38. RUTACEAE p. 132

61. Fruit drupaceous; branches not spinescent . .40. BURSERACEAE p. 133

62(55). Ovary 1-celled...... » . .63

62. Ovary 2- several-celled ...... 68

63(62). Fruit indehiscent ...... 63. PASSIFLORACEAE p. 160

63. Fruit dehiscent ...... 64

64(63). Stamens free, their filaments not coalesced ...... 65

64. Stamens connate into a tube or their filaments adnate basally into

shallow cup. .. o ...... 67

65(64). Sepals 2 ...... 18. PORTULACACEAE p. 93

65. Sepals 4-5...... 66

66(65). Leaves opposite ...... 20. CARYOPHYLLAC.EAE p. 93

66. . Leaves alternate: Genus Cleome...... 26. CAPPARID AC EAE p. 98 70

67 (64), Seeds embedded in a fleshy aril; style 2-5 branched; fruit a

capsule; stipules none: Genus Stegnosperma * . » e . « .

o o . o . .. o o , o o . o » . o o . . .16. PHYTOLACCACEAE p. 92

67. Seeds without aril; style 1; fruit a legume; stipules present:

Sub-family Caesalpinioideae...... 32. LEGUMINOSAE p. 102

68(62). Pistils 3-5; distinct; herbage commonly fleshy; fruit

follicular ...... 27. CRASSULACEAE p. 99

68. Pistil 1, or 2-several connate carpels; herbage not markedly

fleshy; fruit various...... 69

69(68). Fruit indehiscent, or separating into 2-several indehiscent

nutlets, or achene-like segments ...... 70;

69. Fruit dehiscent ...... 72

70(69). Stamens distinct, the filaments not connate nor adnate to other

structures: Genus Kallstroemia . . . .37. ZYGOPHYLLACEAE p. 132

70. Stamens connate into a tube or coalesced into a shallow cup at the

base ...... o ...... 71

71(70). Petals with a bilobed ligule within; leaves alternate; calyx

lobes not glandular without...... 36. ERYTHROXYLACEAEpi 132

71. Petals without ligules within; leaves opposite; calyx lobes often

bearing glands on the outer surface. . .42. MALPIGHIACEAE p. 134

72(69). Leaves compound ...... 73

72. Leaves simple, though often more or less lobed or dissected . . .76

73(72). Plants with papery-exfoliating bark, juice resinous and aromat­

ic ...... 40. BURSERACEAE p. 133

73. Plants without papery-exfoliating bark; juice watery, not aromatic;

fruit a dry capsule...... 74 71

74(73)• Stamens free; leaves opposite;stipules usually present; Genus

Guaiacum ...... 37. ZYGOPHYLLACEAE p, 132

74 o Stamens connate into a tube or disk near the base; leaves alter­

nate or basal; stipules none o’ ...... 75

75 (74). Leaves digitately 3-7 foliolate; seeds not arillate; plants

herbaceous ...... 34. OXALIDACEAE p. 131

75. Leaves pinnately compound; seeds encased in a thin fleshy aril;

plants arborescent ...... 41. MELIACEAE p. 134

76 (72) • Stamens 6, tetradynamous; fruit a silique or silicle......

, ...... o.... o : o . 25. CRUCIFERAE p. .97

76. Stamens of some other number or, if 6 not tetradynamous; fruit

otherwise. o o .77

77(76). Styles united into a column about a long carpophore . . . . . »

...... 33. GERANIACEAE p 0 130

77. Styles not united into a column about a carpophore ...... 78

78(77) o Stamens connate into a tube or cup...... o79

78 e Stamens free and distinct...... <>80

79(78). Leaves opposite...... 42. MALPIGHIACEAE p » 134

79. Leaves alternate...... 55. STERCULIACEAE p. 157

80(78). Plants arborescent; capsule echinate or tuberculate, woody:

Genus Esenbeckia' ...... o * o .... 38. RUTACEAE p. 132

80. Plant herbaceous; capsule not echinate or woody ......

...... 35. LIMCEAE p. 132

SERIES III. SYMPETALAE

Key to the Families:

1. Flowers zygomorphic...... o ...... 2 72

1 . Flowers actinomorphic or nearly so . . . „ . „ . . . . . „ . , . <,17

2(1). Ovary inferior or partly s o ...... 0 ...... « 3

2 o Ovary superior...... '• ...... e . <> » 5

3(2).. Anthers free, notconnate into a tube; stamens 4; ovules many » .

. .100. GESNERIACEAE p. 212

3. Anthers united into a tube about the style ...... 4

4(3). Flowers crowded into an involucrate head; ovary 1-celled; fruit

an achene, 1-seeded; calyx reduced to a pappus or none » 0 . . .

...... 108. COMPOSITAE p. • 225

4. Flowers not crowded into an invo lucrate head; ovary more than 1-

celled; fruit a capsule, many seeded; calyx herbaceous ......

...... 107. LOBELIACEAE p. 223

5(2). Stamens more or less united by the filaments; corolla not strong­

ly sympetalous ...... 6

5. Stamens distinct, the filaments commonly attached to the corolla;

corolla strongly sympetalous ...... 8

6(5). Leaves compound, rarely reduced to one leaflet; stamens normally

10; petals 5 ...... 32. LEGUMINOSAE p. 102

6 . Leaves simple; stamens less than 10; petals 3 or 5 ...... 7

7(6). Petals 5, 2 of them covered with glandular papillae; stamens 3

or 4; fruit an indehiscent spiny pod « . 31. KRAKERIACEAE p. 101

7. Petals commonly 3,' not glandular; stamens 6 or 8 ; fruit various,

samara, drupe orcapsule ...... 43. POLYGALACEAE p. 136

8(5). Fruit of 2 or 4 dry nutlets, or sometimes drupaceous; stems

often quadrangular...... 9 73

8 . Fruit capsular, not separating into nutlets, somewhat fleshy and

long-beaked in Genus Proboscidea = „ „ * „ „ ...... » o » -10

9(8)• Ovary entire, or longitudinally grooved, or slightly 4-lobed;

style apical; fruit of 2 or 4 nutlets, or drupe-like «, o . • «, »

- ...... - . - - - o o . . ■ . - - - - . .92.- VERBENACEAE p. ■ 192

9. Ovary 4-lobed or 4-parted, the style arising between the lobes;

fruit of (normally) 4 nutlets. ••••••• 93. - LABIATAE p -195.

10(8). Plants root parasites, without chlorophyll, the leaves reduced

to fleshy scales ...... 99. OROBANCHACEAE' p.- 212

10. Plants usually not, or only weakly parasitic with chlorophyll;

leaves with well-developed blades. ® 0 .11

11(10). Plants aquatic...... 101. LENTIBULARIACEAE p « 212

11. Plants terrestrial...... 12

12(11). Stamens normally 5; ovary mostly 3-celled: Genera Bonplandia

and Loeselia ...... 89. POLEMONIACEAE p. 187

12® Stamens usually 2 or 4, rarely 5; ovary 1 or 2-celled (sometimes

it appears as if 4-celled), never 3-celled ...... ® . . .13

13(12). Ovary 1-celled...... o . . . .14

13. Ovary 2-celled* ...... 15

14(13). Capsule with a conspicuous elongate beak, at maturity thus

separating into 2 divergent, long curved horns or claws; stamens

4 , or 2 of them staminodia; anther-cells divergent . . . . . 0 .

...... 98. MARTYNIACEAE p. 212

14. Capsule not with an elongate beak; stamens 4, accompanied by 1

staminodium; anther cells parallel . . . .97. PEDALTAGEAE p. 211 ' ■ ■ 74

15(13)o Capsule long and slender; seeds comose or winged; leaves usu-

ally compound o , ...... «, . 96. BIGNONIACEAE p, 210

15. Capsule relatively short; seeds not comose, rarely winged; leaves

simple, but often slightly to deeply dissected . .... * * .16

16(15). Stems usually terete; seeds numerous, the cotyledons narrow, ,

the seed stalks not persisting on the placenta 0 . - ......

o ...... o . o ...... > 95. SCROPHULARIACEAE p. 205

16. Stems more or less 4-angled; seeds few, the cotyledons broad and . ) heart-shaped, the seed stalks (except in Genus Elytraria)' per­

sisting on the placenta as hardened, hood-like projections * o .

...... 102. ACANTHACEAE p. 213

17(1). Ovary inferior or partly so...... 18

17. Ovary superior, free from the calyx or very nearly so ...... 23

18(17). Flowers in heads subtended by an involucre; calyx reduced to a

pappus or none ...... 108. COMPOSITAE p. 225

18. Flowers not in involucrate heads; calyx limb usually well developed

and not pappus-like, except in VALERIANACEAE ...... 19

19(18). Perianth segments and stamens indefinitely numerous; stems very

succulent, with spines, or barbed bristles, or both, these

borne on cushionlike areoles ...... 67. CACTACEAE p. 162

19. Perianth segments and stamens not numerous; stems not succulent,

or if so, then not areolate and spiny...... 20

20(19). Plants usually with tendrils, climbing or scrambling vines;

anthers more or less united; flowers unisexual, the plant

monoecious or dioecious...... 106. CUCURBITACEAE p. 221 75

20e Plants without tendrils; anthers distinct; flowers mostly perfect »

...... 21

21(20). Calyx limb reduced to bristles, these elongate and spreading

in fruit ...... 105. VALERIANACEAE p . 220

21. Calyx limb not as above ...... 22,

22(21). Leaves alternate or basal; stipules none; fruit a 5-valved,

many-seeded capsule...... 80. PRIMULACEAE p. 175

22. Leaves opposite or sometimes verticellate; stipules present;

fruit a berry, drupe, druplet, nutlet or, if capsule, then

2-cel le d ...... 104. RUBIACEAE p. 217

23(17) . Ovary 1-celled...... 24

23. Ovary 2- or more-celled ...... 32

24(23). Stamens more or less united by the filaments; leaves bipinnate;

flowers in heads or spikes: Sub-family Mimosoideae......

...... 32. LEGUMINOSAE p. 102

24. Stamens distinct, not united by the filaments . . .25

25(24). Fruit a legume; leaves bipinnate; stamens usually much more

conspicuous than the small corolla: Sub-family. Mimosoideae . . .

...... 32. LEGUMINOSAE p. 102

25. Fruit various, not a legume; leaves usually simple, or if com­

pound , never bipinnate; stamens less conspicuous than the i . corolla...... o ...... 26

26(25). Perfect stamens as many as the corolla lobes and alternate with

them, or less numerous...... 85. GENT IANAC EAE p. 176

26. Perfect stamens as many as the corolla lobes and opposite them, or

’more numerous...... 27 76

27(26) . Ovule 1 ...... 81. PLUMBAGINACEAE p 0 175

27. Ovules 2 or more. » o . 0 . . . .28

28(27). Flowers unisexual; juice milky...... 64. CARICACEAE p. 161

28. Flowers perfect; juice not milky. . . .■ ...... <>29

29(28). Plants armed with spines; stem leaves deciduous in drought. . e

...... 57. FOUQUIERIEACEAE p. 158

29o Plants unarmed; stem leaves usually persistent...... 30

30(29). Fruit a follicle...... 27, CRASSULACEAE p. 99

30. Fruit otherwise ...... 31

31(30). Staminodia present; fruit more than 1-seeded; leaves spinose-

tipped ...... 78. THEOPHRASTACEAE p. 174

31. Staminodia absent; fruit usually 1-seeded; leaves not spinose-

tipped ...... o ..... o o o .79. MYRSINACEAE p. 174

32(23). Stamens more or less united by the filaments or (in SOLANACEAE)

by the anthers ...... 33

32. Stamens distinct...... 36

33(32). Flowers unisexual; seeds carunculate: Genus Jatropha......

> . .44. EUPHORBIACEAE p. 137

33. Flowers perfect; seeds not carunculate...... 34

34(33). Stamens numerous; corolla only slightly sympetalous; fruit of

several separating carpels, or a several-celled capsule;

stipules present ...... 53. MALVACEAE p. 151

34. Stamens 5; corolla weakly to strongly sympetalous; fruit otherwise;

stipules none...... 35

35(34). Ovaries 2, connected only by the common stigma; pollen grains

cohering in masses (pollinia); filaments united into a column; 77

fruit a pair of follicles or one by abortion •

...... , 87. ASCLEPIADACEAE p»179

35. Ovary 1, usually 2-celled; pollen grains not cohering in pollinia;

filaments distinct9 the anthers connivent; fruit a berry: Genus

Solanuirio ...... , . . 94. SOLANACEAE p. 200

36(32)o Filaments free from the corolla, or very nearly so; corolla

urceolate or subglobose. „ ...... 77. ERICACEAE p . 173

36. Filaments attached to the corolla . . . o ...... 37

37 (36)o Plants parasitic, virtually devoid of chlorophyll; leaves

reduced to scales: Genus Cuscuta . . . 88. CONVOLVULACEAE p. 183

37. Plants autophytic, green; leaves functional „ .38

38(37). Fruit indehiscent, berry-like, or of nutlets...... 39

38. Fruit dehiscent, capsular or follicular . « o . . » .46

39(38). Fruit at'maturity separating into 2 to,4 dry nutlets or (by

abortion) only 1 ...... 40

39 o Fruit not separating into nutlets ...... e . .41

40(39). Flowers not arranged in scorpioid spikes or racemes; stamens

usually 4, didynamous...... 92 . VERBENACEAE p. 192

40. Flowers in scorpioid spikes or racemes; stamens usually 5 .... .

...... 91. BORAGINACEAE p. 189

41(39). Ovary 2-celled,rarely 3-4...... 42

41o Ovary 3- many celled...... 44

42(41). Ovules several to many in each cell . . . 94. SOLANACEAE p. 200

42. Ovules not more than 2 in each c e l l ...... 43 78

43(42)e Plants not tendril-bearing; stamens 4, didynamous; each cell of

the ovary 1-ovulate: Genus Lantana . . . .92. VERBENACEAE p. 192

43. Plants usually -tendril-bearing;'stamens 5 or if 4 S not didynamous;

each cell of the ovary 2-ovulate ...... 51* V1TACEAE p. 149 .

44(41). Stamens 2 to 4 times as many.as the petals......

. . . o ...... 83. EBENACEAE p. 176

44. Stamens as many as the petals...... 45

45(44). Corolla united only at the base; ovary 5-12 celled; sap of the

plant watery ...... 46. AQUIFOLIACEAE p. 146

45. Corolla with a conspicuous tube; ovary 5-12 celled; sap of the

plant milky...... 82. SAPOTACEAE p. 175

46(38). Ovaries 2, united only by the common style or stigma; fruits

follicular; seeds often comose; juice often milky. . * . . . .

...... 86. APOCYNACEAE p. 177

46. Ovary 1, sometimes deeply parted; fruit capsular; juice usually

clear, milky in some of the CONVOLVULACEAE...... 47

47(46). Ovary 1-celled, or sometimes imperfectly 2-celled by intrusion

of placentae; inflorescence commonly scorpioid......

...... 90. HYDROPHYLLACEAE p. 188

47. Ovary 2-celled or more. . . * ...... 48

48(47). Capsules circumscissile; flowers relatively small in dense

terminal spikes; plants scapose, the foliage leaves all basal. «

...... 103. PLANTAGINACEAE p. 217

48. Capsules not circumscissile . . . .49

49(48). Flowers small in dense axillary clusters, these forming inter­

rupted leafy spikes; plants shrubby. . . .84. LOGANIACEAE p. 176 49o Flowers and inflorescence otherwise; plants various „ • « « „ <> .50

50(49). Stigmas 3; style 1, often 3-cleft: Genus Ipomopsis„ o ......

...... 89. POLEMONIACEAE p* 187

50o Stigmas 1 or 2 or (in CONVOLVULACEAE) sometimes 4 ...... 51

51(50). Ovules 2 in each cell of the ovary; stems often twining . 0 <> .

o ...... o .... . o .. o . o 88. CONVOLVULACEAE p. 183

51. Ovules more than 2 in each cell of the ovary...... 52

52(51). Styles 2, distinctly or partly united; inflorescence often

scorpioid...... 90. HYDROPHYLLACEAE p. 188

52. Style 1, entire . . . . o ...... 53

53(52). Leaves commonly alternate, sometimes fascicled; plants leafy-

stemmed; fertile stamens 5, equal in number to the corolla

lobes...... 94. SOLANACEAE p. 200

53. Leaves, at least the lower ones, opposite, or the plant subscapose

with leaves mostly in basal rosette; fertile stamens 2 or 4,

fewer than the corolla lobes • . . .95. SCROPHULARIACEAE p. 205 80

1. SALICACEAE. Willow Family

1. Winter buds with several imbricated scales, often resinous; flowers

borne on a shallow or cup-shaped disk; stigmas elongate, the

lobes slender; leaves ovate to rhombic-suborbicular......

...... 1. Populus p . 80

1. Winter buds with a single non-resinous scale; flowers without disks;

stigmas short; leaves narrowly lanceolate...... 2. Salix p. 80

1. Populus

One species ...... Populus tremuloides

2. Salix

One species...... Salix bonplandiana

2. PIPERACEAE. Pepper Family

1. Piper

One species...... Piper palmeri

3. JUGLANDACEAE. Walnut Family

1. JugIans

One species...... JugIans major

4. BETULACEAE. Birch Family

1.' Alnus

One species...... Alnus oblongifolia

5. FAGACEAE. Beech Family

1. Quercus (152)

1. Bark rather soft, gray and scaly; leaves if toothed, only mucronate

tipped or rounded, never spinose or aristate tipped; stigmas abruptly dilated on short styles; abortive ovules basal; shell

of the fruit not tomentose within: Sub-genus Lepidobalanus

(White Oaks) 2

L» Bark rather hard, black and furrowed, but scarcely scaly; leaves if

toothed, aristate tipped, never rounded lobed; stigmas gradually

dilated on long styles; abortive ovules usually apical; shell

of the fruit tomentose within: Sub-genus Erythroba1anus (Black

Oaks). e . o . O . . « ...... e o o o . 5

2(1). Veins slightly impressed above, markedly prominent beneath. . . 3

2. Veins not impressed, usually somewhat prominent above, not markedly

beneath. . oo.oo.*o.o..oo...... 4

3(2). Leaves concave beneath, obovate to suborbicular; fruit long-

stalked e ...... *Quercus reticulata

3. Leaves flat, narrowly obovate-oblanceolate, or oblong; fruit sub-

sessile...... Quercus arizonica

4(2). Twigs of the season yellowish-tomentose; leaves densely tomen­

tose; fruit long-stalked; acorn half-included......

...... Quercus chihuahuensis

4. Twigs of the season glabrate; leaves usually glabrous or slightly

scurfy below, or on both surfaces; fruit subsessile; acorn about

one-third included ...... Quercus tuberculata

5(1). Leaves entire ...... Quercus durifolia

5. Leaves toothed or the margins aristate ...... 6

6(5). Leaves not impressed veiny above; bristles of the leaves 5-7 mm.

l o n g Quercus albocincta

6 . Leaves impressed veiny above ...... 7 82

7(6). Leaves very large, suborbicular or broadly elliptic, about 15 cm.

long and broad ...... Quercus pennivenia

7. Leaves smaller, oblanceolate-oblong or elliptical...... o 8

8(7). Leaves aristate, teeth below and above the middle ...... 0 «

...... Quercus epileuca

8 . Leaves aristate, teeth only above the middle . . . Quercus incarnata

6 . ULMCEAE. Elm Family

1. Celtis

1. Branches armed with stout, recurved spines; fruit yellowish,

sparsely short pilose; leaves 3-5 cm. wide . . . Celtis iguanaea

1. Branches unarmed; fruit red or orange, glabrous, becoming wrinkled

in age; leaves 1-3 cm. wide...... Celtis reticulata

,7. MORACEAE. Mulberry Family

1. Plants herbaceous. . • . . . „ ...... • . . . .1. Dorstenia p. 83

1. Plants trees or shrubs ...... 2

2(1). Flowers borne upon the inner surface of a more or less globose,

hollow receptacle, this having at the apex a small opening

closed by scales ...... 2. Ficus p. 83

2 e Flowers variously arranged, but never upon the inner surface of a

closed receptacle ...... « ...... 3

3(2). Pistillate perianth of distinct segments, not enclosing the

fruit; seeds minute...... „ „ * 3. Morus p. 83

3. Pistillate perianth tubular, enclosing the fruit; seeds large. . . ..

...... 4. Trophis p. 83 83

I* Dorstenia

One species...... Dorstenia drakeana

2. Ficus

1. Peduncles solitary; involucre trilobate; stamens 2; leaves glabrous

beneath; receptacle 1.5-2 cm. in diameter, spotted with light

and dark green; branchlets densely pilose-sericeous. . .

o ...... Ficus radulina.

1. Peduncles geminate; involucre bilobate; stamen 1 ...... 2

2(1). Receptacle all sessile; involucre large, conspicuous, enclosing

the receptacle for half its length or more . . Ficus cotonifolia

2. Receptacle all pedunculate ...... o..«3

3(2). Leaf blades conspicuously pubescent beneath . . .Ficus petiolaris

3. Leaf blades glabrous b e n e a t h ...... 4.

4(3). Receptacle 9-12 mm. in diameter, glabrous or minutely puberu-

lent, the ostiole rather large, depressed. . . . Ficus padifolia

4. Receptacle 15-25 mm. in diameter, densely puberulent, the ostiole

not prominent...... Ficus goldmanii

3. Morus

One species...... Morus microphylla

4. Trophis

One species. .Trophis racemosa

8. URTICACEAEo Nettle Family

1. Pistillate flowers subtended by conspicuous green bracts; leaves

entire, small, mostly 1-3 cm. long, stipules none; plant a

herb ...... 1. Parietaria p . 84 84 I 1 e Pistillate flowers not subtended by bracts; leaves crenate-dentate;

longer, more than 3 cm, long and mostly 10-20 cm. wider or

larger, stipules present; plant a shrub...... 2. Urera p. 84

1. Parietaria

One species...... Parietaria debilis

2. Urera

One species...... Urera caracasana

9. LORANTHACEAE. Mistletoe Family

1. Leaves all reduced to small scales . . » o . o » 2

1. Leaves with well developed blades...... 3

2(1). Fruit sessile, sub-globose, red in color; flowers borne above the

bracts on the axils of the spike; anthers 2-celled; parasitic

on legumes; 1000 feet elevation...... 2. Phoradendron p. 85

2. Fruit on short stout pedicels, recurved in age, longer than wide,

not reddish in color; flowers solitary in the axils of the

bracts; anthers 1-celled; parasitic on pine; 5000-6000 feet

elevation...... 1. Arceuthobium p. 84

3(1). Perianth simple; flowers sunk in the axils of the inflorescence .

...... 2. Phoradendron p. 85

3. Perianth biseriate; flowers not sunk in the axils of the inflores­

cence...... o ...... 3. Struthanthus p. 85

1. Arceuthobium

One species...... ^Arceuthobium vaginatum 85

2 . Phoradendron (151)

1 o Leaves reduced to triangular scales9 about 2 mm. long; spikes

axillary, mostly solitary^ with about 4 short joints, 2~ or

exceptionally 4- or 6-flowered in 2 or 4 series; fruit red,

about 3 mm. in diameter...... Phoradendron californicum

1. Leaves with well developed blades...... 2

2(1). Branches compressed at the joints; leaves narrowly lanceolate,

acutish to emarginate, 10-16 cm. long; fruit ovoid, 3 mm. in

diameter, yellowish-tomentose...... Phoradendron scaberrimum

2. Branches not compressed; leaves obovate to lanceolate, very obtuse,

3-5 cm. long; fruit sub-globose, about 5 mm. in diameter, white-

glabrous o ...... Phoradendron engelmannii

3. Struthanthus

One species o ...... Struthanthus haehkeanus

10. OPILIACEAEo Opilia Family

1. Agonandra

One species...... Agonandra racemosa

11. ARISTOLOCHIACEAE. Birthwort Family

1. Leaf blades usually with a broad round auricle at base; utricle to

about 6 mm. long and 3 mm. wide...... Aristolochia brevipes

1. Leaf blades usually with a narrow auricle at base; utricle about 1

cm, long and 7 mm. wide...... Aristolochia quercetorum 12. POLYGONACEAEo Buckwheat Family .

1. Scandent herbaceous vine branching tendrils in inflorescence; calyx

lobes accrescent, at first greenish, but soon purplish-red e » »

...... ,l.o Antigonon p. 86

1. Plant erect, without tendrils...... 2 ' 2(1). Stipules wanting; flowers subtended by an involucre; this long-

peduncled; leaves oblanceolate, chiefly basal; flowers ac­

crescent, glabrous, deep red-brown; achene acuminate, narrowly

winged ...... 2. Eriogonum p. 86

2 o Stipules present, united into a sheath (ocrea); flowers not sub­

tended by an involucre ...... 3

3(2). Perianth segments 6, the three outer spreading, remaining small,

the inner ones usually erect and enlarged in fruit ......

...... 4. Rumex p. 87

3, Perianth segments 5, all erect, similar and erect in fruit .....

...... 3. Polygonum p. 86

1. Antigonon

One species...... Antigonon leptopus

2. Eriogonum

One species ...... Eriogonum atrorubens

3. Polygonum (142)

1. Rootstock usually much thickened and bulblike; radical leaves well

developed, 10-25 cm. long, 0.5-3 cm. broad; style three-parted

nearly to the base, 3-4 mm. long, exserted; achene triquetous;

alpine and sub-alpine plants ...... Polygonum bistortoides 87

I* Rootstock^ if any; not bulblike; radical leaves none; style two-

parted; achene lenticular, ..'.•-•.•.'.••..•••••2

2(1), Pedicels 2,5-3 mm, long; calyx light-rose color, 2-3 mm. long;

style 1-1.5 mm. long, somewhat exserted; achene ovoid, gibbous

on one side, 0 ,o. ,o ... . Polygonum mexicanum

2. Pedicels 3-4 mm. long; calyx pink or light purple, sometimes reddish

and 3-4 mm. long; style 3 mm. long, mostly included, not

gibbous. . . o , o o .. ® ...... Polygonum pensylvanicum

4. Rumex (118)

One species...... Rumex obtusifolius

13. CHENOPODIACEAE. Goose-foot Family

1. Chenopodium

1. Embryo completely encircling the endosperm; plants farinose, never

glandular or pubescent; seeds 1.3-1.5 mm. broad......

• • • • . . Chenopodium album

1. Embryo not completely encircling the endosperm; plants variously

both pubescent and glandular, not farinose; seeds less than 1

mm. broad...... * ...... 2

2(1). Inflorescence of numerous loosely few-flowered, axillary cymes,

these finally forming narrow elongate naked panicles; pericarp

not gland-dotted; strong scented annual. . . Chenopodium incisum

2. Inflorescence in small glomerules, these disposed in panicles or

spikes; pericarp gland-dotted; ill-scented annual or perennials.

...... so. .Chenopodium ambrosioides 88

14. AMARANTHACEAEo Amaranth Family

1 e Leaves alternate; anthers 4-celled, appearing 2-celled after

dehiscence; ovules erect • ...... 2* Amaranthus p. 89

1. Leaves opposite; anthers 2-celled, often appearing l-celled after

dehiscence; ovules pendulous . . . . , ...... 2

2(1). Perianth tubular9 indurate3 broadly winged5 wings lacerate-

dentate; anthers sessile in sinuses of perianth tube

...... » 3» Froelichia .p. 89

2. Perianth segments distinct; anthers borne oh short or long filaments

or on a staminal tube not attached to perianth segments. . . . 3

3(2). Flowers in few-flowered, rather loose axillary glomerules., these '

subtended by leaves with the bases becoming more or less

hardened and united, forming a turbinate involucre; herbage

densely stellate-pubescent ...... 6. Tidestromia p. 90

3. Flowers in heads or spikes, these naked, or if subtended by leaves,

their bases not becoming hardened and united; pubescence not

stellate . . 4

4(3). Stigma 1 and capitate ...... 1. Alternanthera p. 88

4. Stigmas 2-3, subulate or filiform (sometimes capitate in the

staminate flowers) ...... 5

5(4). Flowers perfect, in heads; anthers 1-celled; ovary turbinate. . »

...... 4. Gomphrena p. 89

5. Flowers unisexual, in a loose panicle of numerous slender spikes;

anthers 2-celled; ovary somewhat compressedi . .5. Iresine p. 89

1. Alternanthera

One species...... Alternanthera stellata 89

2e Amaranthus

1. Plants dioecious; sepals of the pistillate flowers narrowly to

broadly spathulate, 2-3.5 mm. long ...... Amaranthus palmeri

1. Plants monoecious; sepals of the pistillate flowers oblong or linear

oblong9 1.5-2 mm. long ...... Amaranthus hybridus

3. Froelichia

One species...... Froelichia interrupta

4. Gomphrena

1. Bractlets cristate from below the apex nearly to the base, the

crests lacinate-dentate; perianth much shorter than the

bractlets, the lobes linear...... Gomphrena nitida

1. Bractlets not cristate; perianth almost equalling the bractlets.,

the lobes lanceolate ^ .. ; ...... Gomphrena sonorae

.o.oo.o. 5. Iresine

1. Plants herbaceous; staminodia wanting* . . Iresine celosia

1. Plants shrubby; staminodia present 2

2(1). Stigmas short and stout; staminodia about equalling the filaments

and the bracts and bractlets one-third to one-half as long as

the sepals ...... * ...... o .. . Iresine hartmahii

2 * Stigmas slender; staminodia not over one-half as long as filaments;

bracts and bractlets of the pistillate flowers nearly as long as

the sepals ...... 3

3(2). Erect shrub; branches villpus-canescent when young; sepals of

pistillate flowers lanceolate-attenuate; staminodia very short,

broad dissected at the apex into a short filiform segment or

rarely sub-entire...... Iresine calea 90

3 o Scandent or reclining shrub; branches glabrous, or rarely short

villous when young, sepals of pistillate flowers ovate, obtuse;

staminodia half as long as the filaments . . .Iresine interrupta

6. Tidestromia

One species o e -...... Tidestromia lanuginosa

15. NYCTAGINACEAEo Four-o'clock Family

1. Flowers dioecious; leaves mostly opposite; shrub or small tree,

the branches armed with numerous stout spines.5. Pisonia p. 92

lo Flowers perfect; plants herbaceous or suffrutescent...... „ . 2

2(1). Leaves alternate...... 6. Salpianthus p. 92

2 o Leaves opposite...... 3

3(2). Anthocarp lenticular, the margins usually dentate, strongly in­

curved, the dorsal surface bearing 2 rows of stipitate glands. .

...... 1. Allionia p . 90

3. Anthocarp not lenticular, never with dentate margins ...... 4

4(3). Floral bracts united into a calyx-like involucre......

o o ...... 4. Mirabilis p. 92

4. Floral bracts distinct ...... 5

5(4). Fruit 5-angled or ribbed; free portion of the perianth campanu-

late ...... 2. Boerhaavia p. 91

5. Fruit 10-ribbed; free portion of the perianth funnelform ......

.. o ...... 3. Commicarpus p. 91

1. Allionia

One species...... ‘ . ^Allionia incarnata 91

2. Boerhaavia .

1. Fruit pubescent'; perennial plants...... 2

1. Fruit glabrous; annual plants...... 3

2(1). . Pubescence of the fruit glandular; fruit 2.5-3 mm. long ......

...... Boerhaavia cariabaea

2. Pubescence of the fruit not glandular; fruit 3.5-4 mm. long......

...... Boerhaavia gracillima

3(1). Flowers various, never racemose ...... 4

3. Flowers racemose ...... 5

4(3). Perianth.1.5 mm. long or less; fruit 3-3.5 mm. long ......

...... Boerhaavia erecta

4. Perianth 2 mm. long or more; fruit about 2.5 mm. long......

...... Boerhaavia lateriflora

5(3). Ribs of the fruit broad, obtuse, the sulci narrowly linear,

closed and smooth...... Boerhaavia coulteri

5. Ribs of the fruit narrow, acute, the sulci broad and open, rugulose.

6

6(5). Perianth about 3 mm. long; stamens exserted . . .Boerhaavia xanti

6. Perianth 1.5 mm. long or less; stamens included...... 7

7(6). Racemes remotely flowered; bracts usually lanceolate; stems

slightly viscid-puberulent below ...... Boerhaavia torreyana

7. Racemes densely flowered; bracts usually broadly ovate; stems

densely viscid-puberulent, chiefly below . . .Boerhaavia spicata

3. Commicarpus

One species...... Commicarpus scandens 92

4 o Mirabllis

1. Perianth 3-3.5 cm. long, normally ysrplish-red; involucre lobes

longer than the t u b e ...... Mirabilis jalapa

1 o Perianth 10-14 cm. long, usually white tinged with pink or purple;

.involucre lobes about as long as the tube. .Mirabilis wrightiana

5. Pisonia

One species...... Pisonia capitata

6. Salpianthus

1. Perianth 2.5-3 mm. long, slightly exceeding the fruit, green, and

bearing numerous short uncinate hairs. .Salpianthus purpurascens

1. Perianth about 6 mm. long, several times as long as the fruit, red«

dish-green, and without uncinate hairs , Salpianthus macrodontus

16. PHYTOLACCACEAE. Pokeberry Family

1. Flowers with petals, usually 5; ovules 3-5 in each cell of the

ovary; fruit capsular; plant shrubby . . . 3. Stegnosperma p. 92

1. Flowers without petals; ovules 1 in each cell of the ovary; fruit

not capsular; herbaceous plants...... 2

2(1). Sepals and stamens usually 4; stigma capitate . .2. Rivina p. 92

2. Sepals commonly 5, stamens 8-20; stigmas 2, rarely 3, linear or

filiform ...... 1. Phytolacca p. 92

1. Phytolacca

One species...... Phytolacca icosandra

2. Rivina

One species...... o ...... Rivina humilis 3. Stegnosperma

One species ...... Stegnosperma halimifolium 93

17• AIZOACEAE» Carpet-Weed Family

' 1«, MolluRQ

One species...... * ...... « . » . » • ..Mollugo verticillata

18. PORTULACACEAEo Portulaca Family

1 o Talinum (165)

1 o Leaf blades 0*8-2 cm, long, 1-2 mm. broad; low herb, 2-5 cm. high* *

...... oooopoo.. .Talinum marginatum

1. Leaf blades 2-10 cm. long, 1-4.7 cm. broad; tall herb, .25-75 cm.

h i g h ...... * ...... * * . . . . . * . . * * . * 2

2(1). Inflorescence a terminal panicle, 7-25 cm. long, the branches

cymose; sepals 3-4 mm. long, deciduous . . . Talinum paniculatum

2. Inflorescence a few to many-flowered raceme or cyme; sepals 5-6 mm.

long, persistent . * ...... <.*..*. Talinum triangulare

19. NYMPHAEACEAE* Waterlily Family

1. Nymphaea

One species...... * * * * * « * ...... Nymphaea amp la

20. CARYOPHYLLACEAE* Pink Family

1. Stamens 5 (rarely few in one species); style 1 . . 1 * Drymaria p * 94

1* Stamens 10 *..*...... o,...... 2

2(1). Annual plant; leaves spatulate to oblanceolate; style 4; flowers

white...... 3. Stellaria p. 94

2. Perennial plant; leaves lanceolate to ovate; styles 2, flowers

normally pale pink .2. Saponaria p. 94 94

1. Drymaria (21)

1 o Leaves pseudoverticillateo . » ...... 0.2

1 o Leaves opposite. 0 » « » « - « •« o » <, o » « » «, . ■ . . o o « « D 3

2(1). Peduncles, pedicels and sepals devoid of stipitate glandss the

pedicels mostly shorter than the subtending bracts; petals bifid

about half their length. o*Drymaria leptophylla var. leptophylla

2 o Peduncles and often the pedicels and sepals stipitate-glandular? the

pedicels.longer than the subtending bracts; petals bifid

slightly more than half their length . . . .o •• « ' *

o . o » o - ...... ^Drymaria leptophylla var . nodosa

3(1). Leaves linear to elliptic; sepals 3-nerved; stipules entire . o 4

3. Leaves ovate to reniform; sepals 1--nerved; stipules lacerate .... .

<, . . . . o . o o . ■ . o . o*Drymaria gracilis subsp. gracilis

4(3). Peduncles, pedicels and sepals devoid of stipitate glands, the

pedicels mostly shorter than the subtending bracts; petals bifid

about half their length . **Drymaria leptophylla var. leptophylla

4. Peduncles and often the pedicels and sepals stipitate-glandular,

the pedicels longer than the subtending bracts; petals bifid

slightly more than half their length

o ..... o . * . -Drymaria leptophylla var. nodosa

2. Saponarla

One species...... o . ... . Saponarla officinalis

3. Stellaria

One species...... Stellaria montana 95

2 o RANUNCULAGEAEo Crowfoot Family

1 o Two or more ovules per carpel; fruit a follicle, 2

1. Carpels with a solitary ovule; fruit an achene ...... , 3

2(1). Flowers zygomorphic...... 3. Delphinium p , 95

2. Flowers actinomorphic...... 1. Aquilegia p, 95

3(1). Petals present, . . e ,4, Ranunculus p, 95

3. Petals none or rudimentary e e . . 4-

4(3). Sepals usually large and showy, petal-like, somewhat persistent .

, , ...... 2. Clematis p , 95

4. Sepals small, less conspicuous than the stamens, caducous. , , .

, 5. Thalictrum p. 95

1. Aquilegia (105)

One species...... o...... Aquilegia skineri

2. Clematis

One species. . , ...... Clematis drumondii

3. Delphinium (29)

1. Sinus of lower petal about 2 mm. deep; spur straight or slightly

upcurved ...... Delphinium calcar-equitis

1. Sinus of lower petal 3-4 mm. deep; spur usually decurved ......

...... o o ...... Delphinium leptophyllum'

4. Ranunculus (4)

One species...... ^Ranunculus forreri var. forreri

5. Thalictrum (10)

1. Flowers polygamo-dioecious; sepals not at all dimorphic,usually

elliptic, about * 3 mm. long; stigmas filiform, elongate, not

’bialate, ^Thalictrum parvifructum 96

1 o Flowers dioecious; sepals evidently dimorphic, those of male flowers

elliptic, 3.5-6 mm. long, those of female flowers lanceolate or

linear, 1-2 mm. long; stigma short, conspicuously bialate. . . .

...... 4-Thalictrum pinna turn var. sub terna turn

22. MENISPEKHACEAE. Moon-Seed Family

1. Coccuius

One species...... Cocculus diversifolius

-i ■

23. LAURAOEAE (2). Laurel Family

1. Flowers corymbose, subtended by an involucre of membranaceous

bracts; involucres 5-9-flowered, the flowers yellow......

...... o ..... o ...... 1 . Litsea p . 96

1. Flowers not subtended by involucre ...... 2

2(1). Staminodia large, about 8 mm. long, subovate, very pubescent;

stamens with introrse and extrorse anthers, the cells not

arranged in an arc ...... 2. Persea p. 96

2. Staminodia small, inconspicuous, about 1 mm. long; stamens all with

introrse anthers, the cells arranged in an arc o ......

...... 3. Sassafridium p. 96

1. Litsea

One species...... * ...... Litsea glaucescens

2. Persea

One species...... Persea podadenia

3. Sassafridium

One species...... Sassafridium macrophyllum 24. PAPAVERACEAEo Poppy Family

1. Herbage with prickly bristles; flowers short peduncled; capsules

spinesceirt, opening by valves at the top . . . 1. Argemone p. 97

1. Herbage not prickly; flowers long peduncled; capsules glabrous,

opening by pores under the edges of the stigma .2. Papaver p. 97

1. Argemone (103)

One species...... , . . . . .d-Argemone ochroleuca subsp. ochroleuca.

2. Papaver

One species c ...... Papaver somniferum

25. CRUCIFERAEo Mustard Family

1* Stigma with lobes at a right angle to the placentas and septum,

hence over the valves, . ;.. .'...... 6. Thelypodium p. 98 ■ 1. Stigma lobes situated over the placentas '2

2(1). Fruits silicles, rarely more than twice as long as broad. . . . 3

2. Fruits siliques, more than twice as long.as wide ...... 4

3(2). Capsules flattened parallel to the broad partition; seeds

numerous in 2 rows in each cell...... 2. Draba p. 98

3. Capsules flattened contrary to the very narrow partition; seed 1 in

each cell...... 3. Lepidium p. 98

4(2). Siliques conspicuously beaked; embryo with conduplicate cotyle­

dons ...... 1. Brassica p. 98

4. Siliques not beaked; embryo with incubent cotyledons ...... 5

5(4). Plants pubescent with long simple trichomes to nearly glabrous. .

...... 4. Sisymbrium p . 98

5 . Plants pubescent with branched trichomes . . . .5. Descurainia p. 98 98

1 o Brassica

One species...... Brassica campestris

2 o Draba

1. Pubescence a mixture of branched and simple trichomes» . o . . . „ .

. o o . o o o o . . . e . o o o . , e . o , . .Draba cuneifolia

1. Pubescence of branched trichomes only . . « »• « «

\ o .... . '"Draba cuneifolia var. integrifolia

3. Lepidium

One species...... Lepidium lasiocarpum

4. Sisymbrium

One species...... Sisymbrium auriculaturn

5. Descurainia

One species...... ^Descurainia pinnata subsp. ochroleuca

6. Thelypodium

One species Thelypodium longifolium

26. CAPPARlDACEAEo Caper Family

1. Plants herbaceous; flowers perfect; leaves trifoliolate......

...... 1. Cleome p . 98

1. Plant a tree; flowers dioecious; leaves simple, coriaceous, linear

or narrowly linear-oblong...... 2. Forchammeria p. 98

1. Cleome

One species...... Cleome melanospertna

2. Forchammeria

One species...... Forchammeria watsonii 99

27. CRASSULACEA'Eo Orpine Family

1. Acaulescent plants » . » <> » »...... 2

1. Caulescent plants ...... 3-

2(1). Basal leaves small5 less than 2 cm. long; flowers on stems about

15 cm. long; sepals ovate, 3-4 mm. long. .3. Graptopetalum p. 99

2. Basal leaves large, much longer than 2 cm. long; flowering stems

about 45 cm. long; sepals linear, 5-8 mm. long » ......

...... o o ...... 2 o Echeveria p . 99

3(1). Petals usually appendaged at insertion of stamens ......

...... 4. Pachyphytum p. 99

3. Petals not appendagede . . • • « • « ...... 4

4(3). Petals more or less united at base...... 1. Altamiranoa p. 99

4. Petals distinct...... 5. Sedum p. 99

1. Altamiranoa (

One species...... ^Altamiranoa chihuahuense

2. Echeveria

One species...... Echeveria paniculate

3. Graptopetalum

One species ...... Graptopetalum occidentalis

4. Pachyphytum

One species...... Pachyphytum sp.

5. Sedum

1. Annual plant; petals white, some of them with red spots at base. . .

...... Sedum vinicolor

1. Perennial plant; petals porple or if white, never with red spots at

base ...... 2 100

2(1). Sepals linear; carpels widely divergent ...... Sedum madrense

2 e Sepals oblong; carpels erect ...... o . .Sedum mellitulum

28. SAXIFRAGACEAEo Saxifrage Family

1. Heuchera

1 o Stamens exceeding the sepals; hypanthium pinkish, together with the

sepals about 5 mm. long...... Heuchera rubescens

1. Stamens much shorter than the sepals; hypanthium bright red,

together with the sepals about 8 mm. long. . .Heuchera sanguinea

29. PLATANACEAE. Plane-tree Family

1. Platanus

One species ...... Platanus racemosa

30. ROSACEAEo Rose Family

1. Peta 1 s none® . » . . . . ® . . © . . « . . . . ©I. Alchemrlla p . 100

1. Petals present ...... 2

2(1). Leaves compound ©3. Potentilla p. 101

2 o Leaves simple...... 3

3(2) . Fruit a drupe; sepals imbricate in the bud; leaves entire or

serrate, never dentate ...... 4. Prunus p. 101

3. Fruit an achene; sepals valvate in bud; leaves dentate, the teeth

ending in a short, round mucro 2. Holodiscus p. 100

1. Alchemilla (109)

One species...... ^Alchemilla aphanoides var. subalpestris

2. Holodiscus (73)

One species...... ^Holodiscus dumosus var. dumosus 101

3. Potentllla

One species» . • . „ „ ...... Potentilla thurberi

4, Primus (81)

1. Leaves s errate...... + -Prunus serotina subsp. virens var e virens -

1 o Leaves entire. . „ ...... 2

2(1). Leaves oblong-lanceolate, the larger ones mostly less than 5 cm.

long and 2 cm. wide; petiole minutely pilose to glabrous ......

„ . e . . o .Prunus gentry!

2 o Leaves oblong, mostly more than 5 cm. long and 2 cm. wide; petiole

densely pilose ...... Prunus zinggii

31. KRAMERIAGEAE. Rat any Family

1 o Kramer ia (11)

1. Fruit entirely glabrous...... Krameria palmeri

1. Fruit densely pilose or sericeous...... 2

2(1). Stems procumbent, chiefly herbaceous; leaves glabrous above . . .

...... Krameria prostrata

2. Sters erect, often woody throughout...... 3

3(2). Upper petals distinct; spines of the fruit barbed at the apex

only; fruit densely velutinous ...... Krameria paucifolia

3. Upper petals connate near the base; spines of the fruit barbed along

the upper part; fruit rather sparingly strigose......

...... Krameria parvifolia 32. LEGUMINOSAEo Pea Family

Key to the Sub-families

1. Flowers actinomorphic; calyx.and corolla valvate in bud; leaves

usually bipinnate o . . ...» . . . . . I. MIMOSOIDEAE p , 102

1. Flowers zygomorphic; calyx and corolla imbricate in bud; leaves

mostly pinnate or digitate, rarely simple. . . . . « . . . * . 2

2(1). Uppermost petal internal in bud; petals typically 5 and distinct.

o. . . .0.0 ...... o Ho GAESALPINIOIDEAE p. 108

2 o Uppermost petal external in bud; two anterior petals (keel) often

more or less united...... » .IIIe PAPILIONOIDEAE p. 110

Sub-family I. Mimosoideae

1. Anthers gland-tipped ...... 9. Prosopis p . 107

1 o Anthers not gland-tipped ...... , ...... 2

2(1). Stamens usually as many as corolla lobes or twice as many . . . 3

2. Stamens numerous, usually more than twice as many as corolla lobes .

...... / . . . . . , ...... 6

3(2). Valves of pod separating from persistent margins; plants prickly»

" . . . . , ...... , . . o . . . . . 4

3 o Valves of pos not separating from margins; plants not prickly. . . 5

4(3). Valves narrow, scarcely as wide as the thickened margins, contin­

uous; herbaceous plants...... 10. Schrankia p . 107

4 o Valves usually much wider than the margins and breaking up intd

joints, or if not (in Mimosa biuncifera) then the plant a

shrub, rarely herbs...... 7. Mimosa p. 106 103

5(3)o Shrubs or small trees; seeds arranged transversally in pods . . •

. e ...... o . . . 6 . .5 o Leucaena p e 106

5. Herbs or small shrubs; seeds arranged longitudinally or obliquely

in pods...... * . . . . >4. Desmanthus 106

6(2). Stamens free...... 1. Acacia p« 103

6. Stamens united into tube equalling or slightly surpassing corolla. 7

7(6). Valves of pods separating from the margins„ . „6. Lysfloma p. 106

7. Valves of pods not separating from the margins --8

8(7). Legumes elastically dehiscent ...... 3. Calliandra p. 105

8 e Legumes not elastically dehiscent. 9

9(8). Plants unarmed; pods thin, not thickened. . . .2. Albizzia p. 105

9. Plants usually armed; pods not thin, often thickened „ . .

# o o .... o ... o ...... 8. Pithecellobium p. 107

1e Acacia (163)

1. Flowers spicate...... o o ...... 2

1. Flowers capitate or subcapitate...... „ . . „ » . „ . 3

2(1). Petiole flattened, phyllode-like, 1.5-4 mm. wide, 6-30 cm. long;

pinnae 1-4 pairs, caducous; branchlets drooping; plant of a

white and smooth bark...... Acacia willardiana

2. Petiole not flattened, 2.5-4.5 cm. long; pinnae 3-9 pairs, persis­

tent; branchlets not drooping; plant of a faintly fissured bark.

o ...... o c * e ... o . . Acacia coulteri

3(1). Flowers pedicellate, receptacle oblong, ridged arid often

retaining pedicels ...... o ...... 4

3. Flowers sessile or nearly so, borne on a globose, elliptic or short-

oblong, pitted receptacle...... 6 104

4(3) o Leaflets broadly oblong-ob'ovate, 9-20 mm. long, distinctly and

strongly pinnately veined, the laterals prominent,Acacia crinita

4. Leaflets linear to 1inear-oblong, 4-7 mm, long, 1-veined, the

laterals obscure or none » , » » » » , , » « . . . » , 0 , o » 5

5(4). Stems hirsute with long or short spreading hairs. .Acacia villosa

5. Stems glaucous or pubescent with short and usually incurved hairs. .

...... o o .^Acacia angustissima subsp. angustissima.

6(3). Receptacle ovoid to oblong, 3-6 mm. long; legumes about 2 cm.

wide, their valves thin; stupular spines unguiculate . . . 0 » .

...... ooo.o.o ...... Acacia occidentalis

6. Receptacle globose to sub-globose, 2-3.5 mm. long; legumes mostly

less than 2 cm. wide, their valves thick and leathery; stipular

spines straight or boat shaped ...... <, o » 7

7(6). Pod linear, 3-6 mm. wide, constricted between the seeds, readily

dehiscent; calyx glabrous except for sparse marginal cilio-

lation; corolla glabrous . . Acacia constricta

7. Pod oblong, 9-25 mm. wide, not constricted, tardily dehiscent;

calyx and corolla lobes puberulent, at least toward tips . . . 8

8(7). Pinnae 2-6 pairs; pod terete; corolla puberulent full length;

stipular spines slender, 0.5-5 cm. long, 0,5-1.75 mm. in

diameter at base ...... Acacia famesiana

8. Pinnae 6-60 pairs; pod flattened; corolla puberulent only on backs

of lobes; stipular spines stout or concave, 3-10 mm. in diameter

at base...... 9

9(8). Stipular spines often concave, boat shaped; leaves and twigs

glabrous or nearly so; pod glabrous. . . . . , Acacia cymbispina 105

9 o Stipular spines not boat shaped; leaves and twigs densely puberulent

with yellowish green hairs; pod puberulent; calyx one and one-

half to two times as long as b r o a d ...... ,Acacia pennatula

2 e Albizzia

One species...... „ Alb izzia sinaloensis

3. Calliandra

1. Stems herbaceous above ground9 not more than 20 cm„ long; leaflets

strongly 3-5 nerved and reticulate veined» . .Calliandra humilis

1. Stems woody above ground, commonly more than 20 cm. long; leaflets

not strongly 3-5 nerved. . e . . . » ...... 2

2(1). Leaflets few, usually 2 pairs, large and broad......

...... Calliandra rupestris

2. Leaflets several to many, usually more than 3 pairs, mostly small

(except in £. gentryi) ...... 3

3(2). Heads in terminal panicles; leaflets more than 30 pairs,

cultriform, subfalcate ...... Calliandra houstoniana

3. Heads mostly axillary; leaflets not more than 20 pairs, not

cultriform or subfalcate ...... 4

4(3). Leaflets leathery; stipules subulate. . . . Calliandra eriophylla

4. Leaflets thin, not leathery; stipules narrowly ovate to lanceolate 5

5(4). Plants glabrous throughout; calyx about 1 mm. long; corolla 2-2.5

mm. l o n g ...... Calliandra gracilis

5. Plants pubescent, chiefly stems and leaves; calyx about 4 mm. long;

corolla 6 mm. l o n g ...... Calliandra gentryi 4. Desmanthus

1. Petiolar gland below two accessory stipules,, nearly basal» » « , . .

• „ * • e . e o.o...... Desmanthus bicornutus

1. Petiolar gland commonly at or below the lower pair of leaflets,

without accessory stipules ...... o...... 2

2(1). Pinnae 1-7 pairs; petiolar gland ellipsoid. . Desmanthus virgatus

2. Pinnae 1 or 2 pairs; petiolar gland orbicular. . Desmanthus covillel

5. Leucaena

One species...... Leucaena lanceolata

6. Lysiloma

1. Leaflets puberulent on both sides; stipules 5-6 mm. long, narrowly

lance-subulate, pilosulous ...... Lysiloma watsonii

1. Leaflets glabrous, or ciliate and sparsely puberulent along veins

beneath; stipules 9-12 mm. long, ovate, usually glabrous ....

Lysiloma divaricata

7 . Mimosa

1. Flowers capitate...... 2

1. Flowers spicate...... 3

2(1). Leafiest pubescent; prickles purplish at maturity ......

. . Mimosa biuncifera

2. Leaflets glabrous; prickles yellowish at maturity.Mimosa lindheimeri

3(1). Flowers on pedicels 0.5-1.5 mm. long, glabrous. .Mimosa laxiflora

3. Flowers sessile or pedicels less than 0.5 mm. long, sparsely to

densely puberulent ...... 4

4(3). Leaflets linear or oblong, mostly more than twice as long as

’broad. . . . b ...... 5 107

4. Leaflets obovate to subcordate or ovate-lanceolate, not more than

twice as long as broad, or scarcely longer ...... 6

5(4). Leaflets 6-12 mm. long, 2-3 mm* wide ...... Mimosa callithrix

5. Leaflets 3-4 mm. long, 1-1.5 mm. wide...... Mimosa dysocarpa *

6(4). Pubescence of stem, leaves and rachis densely yellowish . . . . .

o .. . .. o .. o ...... o .Mimosa guirocobensis .

6. Pubescence not as above, or the plants nearly glabrous ...... » 7

7(6). Pinnae 2-5 pairs; stamens 8 ...... Mimosa purpurascens

7. Pinnae 5-13 pairs; stamens 10...... Mimosa palmer!

8. Pithecellobium

1* Leaflets 1 pair; rachis of inflorescence 10-30 cm. long or more. . .

e . o . . . o - . ® o . . . , P11hece 11 obium dulce

1. Leaflets 3 to numerous pairs; rachis of inflorescence rarely over

10 cm. long, o . . o . o ...... o ...... o 2 ) 2(1). Flowers glabrous except on margins of lobes; fruit 6-10 mm.

broad, arcuately curved; leaflets 5-18 mm. long...... 0

o e o ...... Pithecellobium undulatum

2. Flowers puberulent; fruit 1-2.5 cm. broad, straight; leaflets 2-8

cm. long ...... o ...... » 3

3(2). Flowers sessile; leaflets 2-3.5 mm. long. .Pithecellobium sonorae

3. Flowers pedicellate; leaflets 3^8 mm. long .Pithecellobium mexicanutn

9. Prosopis (57)

One. species...... 4-Pro sop is glandulosa var. torreyana

10. Schrankia

One species...... Schrankia heterocarpa 108

Sub-family IIe Caesalpinidideae

1. Anthers basifixed, opening by terminal pores or slits; leaves

once-pinnate ...... 2. Cassia p. 109

1. Anthers versatile, dehiscent longitudinally;leaves bipinnate, . . 2

2(1) . Calyx lobes strongly imbricate, 3

2. Calyx lobes valvate or slightly imbricate, . , ...... , , , , * 5

3(2). Heartwood yielding a reddish or purplish dye; pods splitting

longitudinally through sides of valves, sutures indehlscent„ , ,

...... 6. Haematoxylon p, 110

3. Heartwood not yielding a reddish or purplish dye; pods dehiscent -

along sutures or indehiscent ...... 4

4(3). Plants low shrubs, chiefly herbaceous, not spiny; pedicels not

jointed...... 7. Hoffmans egg ia p. 110

4. Plants shrubs or trees, often spiny; pedicels jointed, . . * , , * .

o ...... 1. Caesalpinia p , 108

5(2). Leaf rachis very short, spine-tipped; legume torulose ......

...... 8 o Parkinsonia p. 110

5. Leaf rachis mostly elongate, not spine-tipped...... o, o. 6

6(5). Legume woody, very large; large trees with large scarlet flowers.

...... ,oo...5. Delonix p. 110

6. Legume not woody; usually small trees with small flowers . .... 7

7(6) . Plants armed with short spines ...... 3. Cercidium p . 110

7. Plants u n a r m e d ...... 4. Conzattia p. 110

1. Caesalpinia

1. Stamens twice as long as or more than the petals; leaflets 5-12

pairs...... Caesalpinia pulcherrima 109

1, Stamens as long as or a little longer than the petals; leaflets

usually 2-4 pairs, 5-7 in . platyloba 2

2(1). Pedicels densely stipitate glandular. . . .4-CaesaIpinia caladenia

2 o Pedicels eglandular...... 3

3(2). Leaflets large, mostly 2-5 cm. long, the lateral venation

conspicuous...... Caesalpinia platyloba

3 o Leaflets small, mostly 5-8 mm. long, the lateral venation wholly

obscure...... Caesalpinia palmer!

2. Cassia

1. Fruit not elastically dehiscent; tree, shrub or herb ...... 2

1. Fruit elastically dehiscent; plants herbaceous or barely suffrutes-

cent ...... 5

2(1). Petiole bearing a gland at the base ...... Cassia occidentalis

2...... Petiole eglandular ...... o . 3

3(2). Leaves without glands Cassia emarginata

3. Leaves bearing glands in one or more pairs of leaflets ...... 4

4(3)o Annual herb; legume 2.5-5 cm. long, deeply impressed between the

seeds. Cassia uniflora

4. Shrub or small tree; legume 6-15 cm. long, not impressed between

the seeds ...... Cassia biflora

5(1). Petiolar glands p r e sent...... « . . . . « 6

5. Petiolar glands wanting...... 7

6(5). Perennial plant; longest petals more than 10 mm.; leaflets•usual­

ly not more than 8 pairs, glabrous...... Cassia palmeri

6. Annual plant; longest petals 5-7 mm. long; leaflets usually more

than 12 pairs, long-ciliate. . . . Cassia leptadenia 110

7(5)o Plant perennial; stamens 7; stems velvety-pubescent, not viscid

glandular; legume sparingly to densely pubescent .Cassia covesii

7. Plant annual; stamens 5, sometimes 7; stems viscid glandular; legume

long hispid. . . ,

3. Cercidium

One species......

4. Conzattia.

One species. ,

5. Delonix

One species......

6. Haematoxylon

One species...... Haematoxylon brasilleto

7. Hoffmanseggia

One species...... Hoffmanseggia multiiuga

8 e Parkinsonia

One species. . . . .; . .

: Sub-family III0 Pap i1iono idea e

1. Fruit of several indehiscent 1-seeded segments, those often

separating at maturity, or if reduced to 1 seed-bearing segment,

then ending in a wing (Nissolia) or a hook (Stylosanthes): Tribe

Hedysareae ...... 2

1. Fruit not segmented, but sometimes constricted between the seeds . 7

2(1). Leaflets 1 or 3 ...... o 3

2. Leaflets never 1 or 3...... * ...... 4

3(2). Stipels present at the base of the petiolules; flowers pink or

purple, exceptionally white...... 12. Desmodium p. 121 Ill

3« Stipels none; flowers yellow . . . « . . . . 31. Stylosanthes p. 129

4(2). Terminal joints of the fruit samaroid, with a large terminal

wing; leaflets 5 ...... ’••'•••. 23. Nissolia p« 126

4. Terminal joint of the fruit not as above „ . o 5

5(4). Leaflets 4 or 6 ...... 2. Amicia p. 115

5. Leaflets other than 4 or 6 ...... 6

6(5). Anthera all alike; inflorescence not conspicuously bracteate. « .

...... 1. Aeschynomene p. 115

6. Anthers conspicuously different, some large and basifixed, others

small and versatile; inflorescence conspicuously bracteate . .

...... 36. Zornia p. 130

7(1). Leaves digitate, or rarely simple, 1-foliolate: Tribe Genisteae .

.8

7. Leaves pinnate ...... 9

8(7). Leaflets more than 3; flowers violet; pods not bladder-like . . .

...... 21. Lupinus p. 126

8. Leaflets 3, or the leaves often simple, 1-foliolate; flowers yellow

or orange; pods much inflated, bladder-like......

...... 10. Crotalaria p. 118

9(7). Plants tendril-bearing, or scandent and with even-pinnate leaves:

Tribe Vicieae...... 10

9. Plants never tendril-bearing; never scandent and with even-pinnate

leaves ...... 11

10(9). Stamen tube oblique at apex; style with a tuft of hairs on the

back or all around, just below the stigma. . . .34. Vicia p. 130 112

10o Stamen tube not oblique at apex, style hairy along the inner side

only, with no apical tuft...... 19. Lathyrus p. 126

11(9). Leaflets 3, or rarely only 1 ...... 12

11. Leaflets 5 or more in all or most of the leaves, rarely fewer . .22

12(11). Fruit very small, often shorter than the calyx; margins of the

leaflets denticulate to serrate; flowers capitate: Tribe

Trifolieae ...... 33. Trifolium p. 130

12. Fruit much longer than the calyx, usually linear or oblong; margins .

of the leaflets never denticulate. . .13

13(12). Plants not scandent or twining: Tribe Loteae. .20. Lotus p. 126

13. Plants usually scandent: Tribe Phaseoleae ...... 14 '

14(13). Style barbate about the apex or along one side...... 15

14. Style glabrous...... e!6

15(14). Peduncles I-flowered 22. Minkelersia p. 126

15. Peduncles few to many-flowered...... 25. Phaseolus p. 127

16(14). Rachis of the inflorescence conspicuously nodose...... 17

16. Rachis of the inflorescence not nodose...... 19

17 (16). Vexilar stamen free at the base, connate above with the others .

o ...... @ 6. Canavalia p. 117

17. Vexilar stamen free or connate with the others at the base. . . .18

18(17). Shrub or small tree; branches armed with spines ......

.... 15. Erythrina p . 125

18. Slender, scandent-twining, suffrutescent plant; branches unarmed. .

...... 17. Galactia p. 125

19(16) . Ovules 1-2; flowers usually yellow...... * . .20

19. Ovules numerous , ...... 21 113

20(19) . Seeds transverse; plant not twining .... 14. Eriosema p. 125

20o Seeds longitudinal; plants twining...... 28. Rhynchdsia p. 128

21(19). Calyx tube cylindric* . « ...... 8, Cologania 'p* 117

21. Calyx tube campanulate...... 7. Centrosema p. 117

22(11). Plant a tree; fruits usually large, 2-10 cm. (mostly 5-6 cm*)

long, indehiscent. • .o- •*••.•••••• • 26. Piscidia. p. 128

22. Plants often or mostly herbaceous; fruits dehiscent, sometimes in­

dehiscent, but very small and 1-2 seeded ••»••••... .23

23 (22). Stamens monodelphous or pseudomonodelphous (Vexilar stamen

connate with tube near middle, but free both above and below

point of connation) ...... *24

23. Stamens clearly diadelphous, vexilar stamen wholly free from

stamina! tube* ...... * * . • *27 ■

24(23). Herbage and calyx more or less gland-dotted; pods usually in-

dehiscent* .**..*0.00**00 ...... oooe. .25

24* Herbage and calyx glandless or at least not conspicuously so; pods

usually dehiscent...... « .26

25(24). Ovary 1-ovulate; petals hypogynous, not adnate to stamina1 tube

and the leaves digitately 3- to 5-foliolate. 27. Psoralea p * 128

25. Ovary mostly 2- to 3-ovulate; petals, or some of them with claws

adnate to base of stamina1 tube; leaves usually pinnate* * * . *

...... 11. Dalea p. 119

26(24). Plant herbaceous to shrubby, but not arborescent; leaves

stipulate; ovary usually glabrous. . * * . *32* Tephrosia p. 129

26. Plant arborescent; leaves without stipules; ovary usually strigose.

„ * o o * * ...... 35. Willardia p. 130 114

27(23). Pods indehiscent, or tardily dehiscent...... 28

27. Pods readily dehiscent at maturity, often elastically ...... 31

28(27). Pods strongly inflated or turgid, papery or leathery......

...... 3. Astragalus p. 115 •

28. Pods terete to flattened, not inflated...... 29

29(28) . Leaves not glandular-punctate; pubescence of malpighiaceous

hairs (attached in middle) ; stipules somewhat adnate . . . = =, ...

...... 18. Indigofera p. 125

29. Leaves and stems, and usually calyces, glandular-punctate;

pubescence of basally attached hairs; stipules free from

petioles ...... 30

30(29). Calyx lobes subequal; ovary 1-ovulate; leaflets 3 to 5. . . . .

..... 27. Psoralea p. 128

30. Calyx cleft more deeply between posterior lobes than between

anterior ones; ovary 2- to 4-ovulate; leafletsnumerous. ....

...... 16. Eysenhardtia p. 125

31(27). Seeds strophiolate...... 4. Brongniartia p. 116

31. Seeds not strophiolate...... 32

32(31). Leaves simple; seeds quadrate, notched opposite hilum and

grooved between notches...... 30. Sphinctospermum p. 129

32. Leaves compound of few to many leaflets; seeds often not con­

stricted centrally ...... 33

33(32) . Plants shrubby or arborescent...... 34

33. Plants herbaceous or suffrutesceht...... 35

34(33). Pods strongly inflated, bladder-like; stipels none; two brac-

teoles beneath each flower; style glabrous . .13. Diphysa p. 124 115

34o Pods not inflated; stipels present; bracteoles none; style

bearded...... ■ . * . • • . . 9. Coursetia po 117

35 (33) • Style glabrous...... 29. Sesbania p. 129

35. Style bearded . . . . « . . . « ...... • . . . . • • • . 036

36 (35)o Stipules spinescent; pods without cross partitions; plant of

High Pine Forest, about 7000 feet elevation. .24. Peteria p. 127

36. Stipules not spinescent; pods with cross partitions between the

seeds; plants of Short-tree’ or Oak Forest, 2000-45000 feet

elevation...... o.. . .5. Benthamantha p. 116

1. Aeschynomene (129)

1. Shrub; stipules attached at base, not peltate......

. Aeschynomene fascicularis

1. Herb; stipules peltate, appendiculate below the point of attach­

ment ...... o ...... 2

2(1). Inflorescence scarcely half as long as the leaves, fasciculate;

leaflets mostly 10-15 mm. long; flowers 6-9 mm. long ......

...... i-Aeschynomene villosa var. longifolia

2. Inflorescence about as long as the leaves or longer; leaflets

usually less than 10 mm. long......

...... -fAeschynomene villosa var. villosa

2. Amicia

One species...... Amicia zygomeris

3. Astragalus

1. Annual plant; petals purple...... ^Astragalus gentry!

1. Perennial plant; petals yellowish-white...... Astragalus hartwegii 116

4 o Brongniartia

1 e Branchlets, and leaflets glabrous; flowers yellow ......

. * . . . . o ...... Brongniartia tenulfolia

1 o Branchlets, and leaflets, pubescent; flowers rose to purple » . - . 2

2(1) • Lower three calyx lobes united to above the middle...... » »

o o ...... Brongniartia lunata

2. Lower three calyx lobes free to near the base or at least below the .

middle ...... o 3

3(2). Flowers pseudo-racemose, the floral leaves all or the upper ones

reduced to the mere stipules, which resemble bracts; flowers 2

to 5 at each node. .Brongniartia palmer!

3. Flowers strictly axillary...... 4

4(3) . Leaflets subcoriaceous; stipules broadly semicordate, somewhat

lunate; flowers rose colored . . » o o . . » Brongniartia lunata

4. Leaflets thin; stipules obliquely ovate, sometimes falcate;

flowers deep purple...... Brongniartia alamosana

5. Benthamantha

1. Plants herbaceous, decumbent; roots tuber-bearing. . e ...... o

. .Benthamantha glabrescens

1. Plants fruticose or suffrutescent, with erect branches ...... 2

2(1). Calyx lobes, at least the lowest one, nearly as long as the tube.

...... Benthamantha mollis

2. Calyx lobes only slightly longer than the tube ...... 3

3(2). Pods puberulent; stem sparingly pilose with spreading hairs . . »

...... •Benthamantha af. wrightii 117

3 o Pods glabrous; stem pubescent with ascending h a i r s ...... » » <>

...... Benthamantha edwardsii

6. Canavalia (112)

One species o „ e ..o • Cana valia villosa

7» Centrosema

One species o ...... « ...... Centrosema virginianum

8. Cologania (125)

1. Leaflets one • . . « • ...... <> »

1. Leaflets usually three ...... 2

2(1) . Leaflets linear to narrowly oblong - ...... 3

2 o Leaflets oblong* . * * ...... 5

3(2). Leaflets pubescent above- . . . . .

3. Leaflets glabrous above» - • » ...... 4

4(3). Pubescence on calyx appressed; pods 3 cm. long or less. * . - * »

eeoeeeeoeeo eceeoeo . . . .Cologania intermedia

4- Pubescence on calxy spreading; pods 5 cm. long or more

ooooo-c-coe- co-o o c

5(2). Stems climbing*...... 6

5. Stems not climbing...... » -

6(5). Hairs on calyx appressed- . , » * » . . . - * .Cologania scandens

6- Hairs on calyx spreading - * - - - » - *

7(5). Petiole very short or wanting . - * -

7. Petiole elongate .

9. Coursetia

One species...... * . . 118

10o Crotalaria (136)

1. Leaves all simple» ...... « ...... » 2

1 e Leaves trifoliola.te e . „ . . „ . . « ...... 5

2(1), Pubescence of stems and leaves appressed, sericeous » » » » . „ . .

• «, e e .» e o' o o e » . . o >Crotalaria purshli var* polyphylla

2. Pubescence, of stems and leaves spreading ? hirsute» » . * . . . •• 3

3(2). Plant decumbent, perennial; leaves ovate, elliptic or orbicular;

stipules small or absent; racemes commonly 3 to 6~flowered . o »'

...... o . . . .ooocoo . ... Crotalaria ahgulata

3 o Plant erect, annual or perennial; leaves narrowly ovate to linear;

stipules usually present, triangular, decurrent;on the stem;

racemes 2 to 4-flowered. . . » ...... » . 4

4(3). Usually annual plants; leaves narrowly ovate to lance-ovate;

bracts narrowly lanceolate, sessile; corolla normally equal to

the c a l y x ...... Crotalaria tuerckheimli

4. Annual or perennial plants; leaves variable, lanceolate to linear;

bracts ovate-lanceolate, slender stalked; corolla normally

exceeding the calyx...... Crotalaria sagittalis

5(1). Legume pubescent with spreading hairs ..... Crotalaria incana

5. Legume pubescent with closely appressed hairs...... 6

6(5). Calyx lobes considerable longer than the calxy tube; leaflets

usually large, mostly 3-7 cm. long . . . . Crotalaria sonorensis

6. Calyx lobes equalling or slightly longer than the calyx tube;

leaflets small, usually 0.7-3.0 cm. long ...... 7

7(6). Erect; tall plant, 0.6-1.5 m. high; leaflets mostly elliptic or

slightly obovate; flowers large (rostrum of the carina 1.3-3.5 119

cm. long); back of standard glabrous, except' for a few hairs

along the mid-vein ...... Crotalaria longirostrata

7. Erect or decumbent; short plant, 4-30 cm. high; leaflets obovate to

oblong; flowers small (rostrum of the carina 0,6-1.1 cm, long);

back of standard pubescent at the tip...... Crotalaria pumila

11. Dalea

1. Wing and keel petals distinctly clawed, inserted some distance

below the mouth of the stamina1 tube, the keel petals (if

present) inserted higher up than the wings, the former usually

united along the lower edge of the blades. ••••...••.2

1. Wing's and keel petals clawless, or short-clawed, all distinct and

inserted at the mouth of the stamina 1 t u b e ...... <>17

2(1), Flowers racemose, with distinct pedicels, reflexed, at least in

age...... o . . . 6 3

2. Flowers spicate or subcapitate, sessile, usually ascending .... 8

3(2), Calyx lobes shorter than or barely equalling the tube . .... 4

3. Calyx lobes longer than the t u b e ...... 7

4(3) . Calyx hairy without ...... 5

4. Calyx glabrous without ...... 6

5(4). Leaves glabrous or essentially so; calyx tube nearly glabrous;

lobes pubescent...... Dalea palmeri

5. Leaves pubescent, at least along margins and midvein; both calyx

tube and lobes pubescent ...... Dalea parryi

6(4). Leaf rachis distinctly winged, constricted at the node. . . , . .

...... 4-Da lea nutans

6. Leaf rachis not winged, merely slightly margined . . . Dalea diffusa 120

7(3). Calyx lobes nearly equal, not obscured by pubescence...... »

...... Dalea calycosa

7. Calyx.lobes unequal, the lowest one much longer, usually obscured

by dense pubescence. . . * ...... Dalea alamos ana

8(2) . Annual plants ...... 9

8o Perennial plants o ...... « .12

9(8)o Staminal tube long-exserted, about twice as long as the calyx

tube coo...... o © o o • o . o o o c Dalea exserta .

9. Staminal tube not long-exserted...... 10

10(9) . Corolla ochroleucous . . ® 0 » . . -fDalea elata

10. Corolla purple to white ...... 11

11(10). Spike short, headlike, globose or nearly so . .Dalea filiformis

11o Spike elongate, cylindric ...... Dalea leporina

12(8). Calyx lobes short, ovate or lanceolate, usually much shorter

than the tube...... 13

12. Calyx lobes subulate-tipped, usually longer than the tube . . . .15

13(12). Corolla purple or pink...... Dalea tomentosa

13. Corolla white ...... » ...... » . . .14

14(13). Leaflets more than 1.0 cm. long, oblanceolate or cuneate-oblong

to obovate; bracts shorter than the calyx, caducous. . . . . * *

...... 4Dalea leucostachys

14. Leaflets 3-6 mm. long, linear; bracts covering the calyx persistent

...... o . e ..... e d* *Daiea lumholtzii

15(12). Plants herbaceous . . . H-Dalea elata

15. Plants more or less shrubby .16 121

16.(15) . Spines terminating the stems or branches. . . • . Dalea pulchra

16. Spines at the end of short axillary branches as well as at the

ends of the main branches. . = . » .. . • . . . . . +Dalea scandens

17(1). Stamens 5 ••••••••' .•••o -.•••• • +Dalea obreniformis

17 o Stamens 10, rarely 9...... 18

18(17) . Corolla w h i t e ...... „ ...... »19

18. Corolla (except sometimes the banner) blue or purple...... 22

19(18). Stems and leaves glabrous .20

19o Stems and leaves pubescent...... ;. . . . .21

20(19). Leaflets oblong to oval; bracts villous-pilose throughout . . .

. . Dalea gray!

20o Leaflets linear; bracts puberulent, long hairy. « .Dalea revoluta

21(19). Stems and leaves long-villous ...... Dalea watsoni

21. Stems and leaves short-pubescent or puberulent. . >\Dalea albiflora

22(18). Perennial plants; bracts pubescent throughout d-Dalea pringlei

22. Annual plants; bracts strongly ciliate on the margins ......

...... o .... *Dalea cliffortiana

/ 12. Desmodium (133, 134)

1. Leaves all unifoliate...... 2

1. Leaves trifoliolate, or predominantly so ...... 4

2(1). Leaflets ovate, ovate-oblong or lanceolate-oblong, strigulose,

the margins hispid-ciliate; legume glabrous......

...... Desmodium guadalajarum .

2. Leaflets linear, grasslike, glabrous, or sparsely hirtelous on the

nerves, the margins not hispid-ciliate; legume pubescent . . . 3 122

3(2). Stem glabrescent to densely uncinate-puberulent; petiole 0.2-1.0

cm. long; pedicels 3.5-6.5 mm. long, uncinate-puberu1ent and

sparsely strigulose. .Desmodium angustifo1ium var. angustifolium

3. Stems glabrescent to moderately uncinate-puberulent; petiole 1 o7-3

cm. long; pedicels 11-16 mm. long, very moderately uncinate-

puberulent .becoming sparsely so in age o' • . . » . . ■ . . ; . •

. o o o e o . o o o . . ^Desmodium angustifolium var. gramineum

4(1). Fruit less deeply notched above than below. ••••••«•.

4. Fruit equally notched on both margins, hence appearing moniliforme10

5(4). Stems diffuse or procumbent . . „ . . ..o.o...... e6

5. Stems erect or ascending • • • . • « • • • ...... „ . 8

6(5). Banner 10-12 mm. long; leaflets orbicular or nearly so; stipules

10-14 mm. long ...... o .Desmodium prostratum

6. Banner 6-8 mm. long; leaflets broadly ovate to ovate-elliptical or

lance-ovate to lance-oblong; stipules 2-3 mm. long ...... 7

7(6). Leaflets broadly ovate to ovate-elliptical; stems densely

pubescent with stiff hooked hairs; joints of fruits densely

uncinate-pubescent ...... Desmodium pringlei

7. Leaflets lance-ovate to lance-oblong; stems sparsely puberulent;

joints of fruits sparsely uncinate-puberulent to glabrate. . . .

...... Desmodium batocaulon

8(5). Bracts not conspicuously or noticeably imbricate, subulate or

narrowly lanceolate; terminal leaflets oblong, ovate, or ob-

ovate, 2- to 3- times as long as wide. . . Desmodium cinarescens 123

8 o Bracts conspicuous before anthesis3 imbricate, lanceolate or ovate-

lanceolate, usually more than 4 mm. long; terminal leaflets

commonly linear-lanceolate, 5 or more times as long as wide. . 9

9(8). Leaves nearly sessile; leaflets not more than 8 mm. broad .■» . . -

...... oDesmodium arizonicum

9# Leaves long-petiolate, 3-4 cm. long; leaflets usually more than 10

mm. broad . Desmodium macrostachium.

10(4). Plants woody throughout or nearly so; erect shrubs usually 1-3

meters high. . . » * . . . . . » , . . » . . » . . « „ . . . .11

10. Plants herbaceous throughout, or suffrutescent only near the base,

often decumbent or prostrate ...... 12

11(10). Joints of the loment 3.5 mm. wide, evidently asymmetric, the

pubescence of spreading hairs...... Desmodium cajanifolium

11. Joints of the loment scarcely 2.5 mm. wide, symmetric or nearly so,

the pubescence of minute, closely appressed hairs......

o . o . „ o . o ...... o . o o . .Desmodium nicaraguense

12(10). Plants annual ...... 13

12. Plants perennial...... 15

13(12). Articles of loment with only sinuate margins, loment entirely

without spirally twisted aspect...... Desmodium neo-mexicanum

13. Articles of loment with opposite margins alternately strongly

involute and revolute, giving loment a spirally twisted

appearance...... 14

14(13). Leaves with leaflets essentially uniform in shape throughout

the plant...... Desmodium procumbens var . procumbens 124

14. Leaves with leaflets variously•shaped throughout the plant, those

of lower leaves broader than long...... „ o .

...... = . .'

15(12) e Margins of the joints of loment conspicuously revolute and in­

volute, the loment thus appearing twisted, except sometimes

when mature...... 16

15. Margins of the joints of loment neither revolute nor involute,

except when very young, the loment never appearing twisted . .17

16(15). Joints of the loment about 2.5 mm. wide . . Desmodium distorturn

16. Joints of loment 3 mm. wide ...... Desmodium purpureum

17(15). Leaflets small, the terminal one not more than 12 mm. long and

7 mm. broad...... Desmodium wislizeni

17. Leaflets large, the terminal one more than 15 mm. long and broad.18

18(17). Leaflets orbicular to round-ovate ...... Desmodium mexicanum

18. Leaflets not as above ...... 19

19(18). Leaflets lanceolate ...... Desmodium af. madrense

19. Leaflets oblong to elliptic of obovate. . . .Desmodium hartwegianum

13. Diphysa

1. Inflorescence and branchlets conspicuously glandular-viscid. . . „ «

. . . o ...... Diphysa racemosa

1. Inflorescence and branchlets glabrous...... 2

2(1). Floral bractlets broadly ovate-acuminate, 5-6 mm. long; leaflets

rather firm, strongly veined beneath, the margins somewhat

revolute; pods about 10 mm. broad...... Diphysa suberosa 125

2, Floral bractlets ovate, 1-2 nun. long; leaflets thin, neither

revolute-margined nor prominently veined beneath; pod about

15-20 mm. broad. •••••••••••.. .Diphysa occidentalis

14. Eriosema

1. Flowers in short headlike racemes, shorter than the leaves . . „ . ,

...... Eriosema pulchellum

1. Flowers in elongate racemes, these usually exceeding the leaves. «

. . Eriosema grand if lorum

15. Erythrina (70)

One species...... Erythrina flabelliformis

16. Eysenhardtia (106)

One species. . 0 . 0 . .Eysenhardtia polystachya

17. Galactia

One species...... Galactia striata

18. Indigofera

1. Calyx one-half or more than half as long as the corolla, its teeth

subulate or subulate-tipped, twice as long as the tube or more .

...... + Indigofera macilenta

1. Calyx less than half as long as the corolla, its teeth lanceolate or

or deltoid, not at all or not much exceeding the tube in length

. 2

2(1). Pods 1.0-2 cm. long, slightly flattened, strongly curved, 3-7

seeded ...... Indigofera suffruticosa

2. Pods not more than.8 mm. long, oblong, rounded-ovoid or sub-globose,

1-2 seeded ...... 3

3(2). Pods oblong, 6-8 mm. long, usually 2-seeded Indigofera densiflora 126

3. Pods rounded-ovoid or sub-globose, 3-3,5 mm. long, usually 1-

seeded „ . . . * ...... Indigofera sphaerocarpa

19, Lathyrus

One species« ...... Lathyrus graminifolius

20. Lotus

1 o Stipules well developed, herbaceous. » » o . . . 2

1. Stipules gland-like or obsolete* ...... * o * o * 4

2(1). Plants annual, usually erect; leaflets oblanceolate ......

...... Lotus chihuahuanus

2* Plants perennial, usually prostrate or procumbent...... 3

3(2). Leaflets 3-5, not mucronate; peduncles mostly 2-flowered, oc­

casionally 1-4; calyx glabrous ...... Lotus alampsanus

3 o Leaflets 5-9, mucronate; peduncles more than 2-flowered, commonly 5;

calyx pubescent...... Lotus repens

4(1). Plants annual; leaflets broadly obovate; peduncles mostly shorter

than the subtending leaves ...... Lotus tomentellus

4. Plants perennial; leaflets linear to narrowly oblong; peduncles

mostly exceeding the subtending leaves ..... Lotus puberulus

21. Lupinus

One species...... Lupinus sitgreavesii

22. Minkelersia

One species Minkelersia galactoides

23. Nissolia (130)

1. Fruit and usually the calyx, beset with numerous glandular setae „ »

...... Nissolia platycarpa

1. Fruit glabrous to pubescent but lacking glandular setae...... 2 127

2(1). Flowers (8-) 10-12 mm. long; calyx tube (2-) 3-4 mm. long, the

teeth 2-4 mm. long Nissolia schottii

2. Flowers 4-7.5 mm, long; calyx tube about 1,5 mm, long, the teeth

0,5-1,5 mm, l o n g ...... Nissolia hirsuta

24. Peterla (114)

One species o ,,o., -KPeteria pinetorum

25, Phaseolus

1. Plants from a globose tuber; stems erect, (orIslightly twining)

seldom more than 30 cm, long; leaflets lance-linear, less than

10 mm. broad; calyx not subtended by bractlets ......

, , , o . , . o » o o , . . » . . o , . . . .Phaseolus parvulus .

1. Plants not from a globose tuber; stems twining, usually over 30 cm*

long; leaflets various; calyx often subtended by bractlets,

these usually deciduous before anthesis. . 2

2(1), Leaflets all trilobate, rarely entire, terminal lobe lanceolate-

oblong, acute at apex, the lateral ones smaller, usually

rounded at apex...... Phaseolus• amabilis

2. Leaflets entire, or if lobed, only the lower ones...... 3

3(2). Pods not more than 6 cm. long ...... ,.o ^ 4

3. Pods more than 6 cm. long ...... 9

4(3). Plants annual; leaflets mostly linear-lanceolate to ovate-

lanceolate ...... Phaseolus acutifolius

4. Plants perennial; leaflets ovate to rhombic-ovate or narrowly oblong

to ovate-oblong...... 5

5(4). Pods commonly more than 5 mm. wide...... Phaseolus metcalfei

5. Pods commonly less than 5 mm. wide ...... 6 128

6(5). Calyx teeth sub equal, as long as or longer than the tube. . . „ .

o o . o o o . o . - o ...... Phaseolus heterophyllus

6. Calyx teeth very unequal, some of them shorter than the calyx tube.7

7(6). Pods glabrous ...... Phaseolus sonorensis

7. Pods pubescent <, ...... » .' ...... 8

8(7). Stipules ovate, 4-6 mm. long; stems puberulent and pilose with

long spreading or retrorse hairs .... .Phaseolus anisotrichos.

8. Stipules triangular-oblong, about 3 mm. long; stems puberulent and

pilose with short hairs or nearly glabrous . . .Phaseolus pauper

9(3). Pods not over 7 mm. broad ...... o . . . *10

9. Pods wider, usually 10-13 mm. broad...... ,.11

10(9). Leaflets densely pubescent beneath; stipules oblong; pods 3-4

mm. broad...... Phaseolus speciosus

10. Leaflets sparsely pubescent beneath; stipules deltoid-lanceolate;

pods about 7 mm. broad . Phaseolus gentryi

11(9). Legume straight, compressed...... Phaseolus pachycarpus

11. Legume curved, subterete...... Phaseolus caracalla

26. ]?iscidia

One species...... Piscidia mollis

27. Psoralea (101)

One species...... Psoralea pentaphylla

28. Rhynchosia

1. Pods distinctly constricted between the seeds.Rhynchosia pyramidalis

1. Pods not constricted between the seeds ...... 2

2(1). Flowers large, 1.5-2 cm. long ...... Rhynchosia macro car pa

2. Flowers small, usually 10 mm. long or less ...... 3 129

3(2). Leaflets broadly rhombic-ovate, usually about as broad as long„ »

...... o . Rhynchosia minima

3* Leaflets ovate, triangular-ovate or ovate-lanceolate, usually

longer than broad . . . . 4

4(3). Stems densely viscid-pilose; leaflets conspicuously reticulate

v e i n e d ...... » . o = « o <> . « » . . .Rhynchosia rariflora

4. Stems scarcely at all viscid-pubescent; leaflets not reticulate

veined . . .Rhynchosia nigropunctata

29. Sesbania

One species...... Sesbania sesban

30. Sphinctogpermum

One species. . . . Sphinctospermum constrictum

31. Stylosanthes (86)

One species. 4-Stylosanthes viscosa

32. Tephrosia (167)

1. Style glabrous; stems herbaceous ...... Tephrosia purpurea

1. Style barbate; stems usually woody or suffrutescent...... 2

2(1). Ovary glabrous on the valves, strigillose along the upper suture;

legume glabrous or with a few hairs on the upper suture. ....

e e e ...... Tephrosia leiocarpa

2. Ovary pubescent; legume hairy, strigillose to strigose or hirsute. 3

3(2). Vexilar stamen completely free from the stamina1 tube ......

.' ...... Tephrosia palmeri

3. Vexilar stamen united with the tube but free at the base . . . . . 4

4(3). Flower-buds 2 at a node, usually only 2 flowering; an thesis pro­

ceeding centrifugally...... 4-Tephrosia thurberi 130

4. Flower-buds 5-12 at a node, usually 5 or more flowering; anthesis

proceeding irregularly ...... 5

5(4). Inflorescence terminal and exillary, the latter usually first

and best developed; leaflets 15-37, predominantly 21-35; ovules

and seeds 8-10 ...... *Tephrosia multifolia

5. Inflorescence usually terminal (sometimes 1-5 slender inflorescences

present at the upper axils); leaflets 9-21; ovules and seeds

4-8...... *Tephrosia nicaraguensis

33. Trifolium

1. Heads distinctly involucrate ...... Trifoliuminvolucratum

1. Heads without distinct involucres...... Trifolium goniocarpum

34. Vicia

1. Peduncle (6-) 8- to 25-flowered...... Vicia pulchella

1. Peduncle 1- to 2-flowered...... Vicia exigua

1 35. Willardia

One species...... Willardia mexicana

36. Zornia

One species...... Zornia diphylla

33. GERANIACEAE. Geranium Family

1. Geranium (87)

1. Leaves divided to the base; lobes pinnatifid-toothed with long,

linear to linear-lanceolate segments ...... 2

1. Leaves divided one-half to three-fourths to the base; lobes

variously toothed with wider segments...... 3 131

2(1). Leaf blades densely appressed-white canescent on both surfaces;

pedicels glandular; stamen filaments mostly longer than the

sepals, often red, conspicuously exserted in fruit

o . o a e . o e e o e © » e e. e ♦ e e e • e e o> Ger UU lUIIl niVeUIEI

2 o Leaf blades densely strigillose above and at least on the veins

below; pedicels not glandular; stamen filaments shorter than

the sepals, yellow-green, not conspicuously exserted in fruit. «-

. . . . o ...... coo.... Geranium charucanum

3(1). Basal leaves few, not long-persistent; cauline leaves numerous;

peduncles l«2-4 or rarely to 6.5 cm. long; fruit 18-25 mm. long;

style-beak 1*5-2.5 or rarely 3 mm. long. . + ^Geranium wislizeni

3. Basal leaves numerous, persistent; cauline leaves few; peduncles 7~

25 cm. long; fruit 32-35 mm. long; style-beak 4-5 mm. long . . .

. . „ . o . * ...... *Geranium mexicanum var * resimum

34. OXALIDACEAE* Oxalis Family

1. Plants caulescent; rootstock usually slender; petals normally light

yellow . * ...... Oxalis albicans

1. Plants acaulescent; rootstock bulb-like, covered by scales; petals

never y e l l o w ...... 2

2(1). Leaves trifoliolate « Oxalis latifolia

2. Leaves 4- to 7-folio late * ...... 3

3(2). Leaflets mostly 5-7, the blades not lobed; capsules columnar,

9-11 mm. long...... Oxalis lanceolate

3. Leaflets 4, the blades lobed at apex; capsules broadly oblong, 5-6.5

mm. long ...... Oxalis divergens 132

' 35. LINACEAE.. Flax Family

1. Llnum

One species...... Linum greggil

36. ERYTHROXYLAGEAE. Coca Family

1. Erythroxylon

One species...... Erythroxylon mexicanum

37. ZYG0PHYL1ACEAE. Caltrop Family

1. Shrub; petals blue; stipules deciduous ...... 1. Guaiacum p . 132

1. Herb; petals yellowish or orange; stipules usually persistent. . . .

...... 2. Kallstroemia p. 132

1. Guaiacum

One species. Guaiacum coulter!

2. Kallstroemia

1. . Flowers small; petals 4-5 mm. long; leaflets 3-4 pairs; beak 1-2 mm.

long, shorter than the body of the fruit; nutlets strongly

reticulate on the faces...... Kallstroemia brachystylis

1. Flowers large; petals 12-25 mm. long; leaflets 5-9 pairs; beak 8-10

mm. long, twice as long as the body of the fruit or longer; nut­

lets slightly reticulate on the faces. .Kallstroemia grandiflora

38. RUTACEAE. Rue Family

1. Flowers perfect; plants unarmed; leaves simple .1. Esenbeckia p. 132

1. Flowers unisexual; plants usually armed with sharp-hooked stipular

prickles; leaves pinnate ...... 2. Zanthoxylum p. 133

1. Esenbeckia

One species...... Esenbeckia hartmannii 133

2 e Zanthoxylum

One species o e '...... Zanthoxylum fagara

39. SIMAROUBACEAEo Quassia Family

1. Alvaradoa

One species...... Alvaradoa amorphoides

40. BURSERACEAEo Bursera Family

1. Bursera (82, 127)

1. Drupes bivalvate; flowers tetramerous ...... * 2

1. Drupes trivalvate; flowers pentamerous ...... 5

2(1). Leaves always bipinnate ...... Bursera stenophylla;

2. Leaves simply pinnate, with 5- many leaflets ...... o .... 3

3(2). Leaflets conspicuously pubescent beneath even at maturity, on the

surfaces as well as on the costa ...... Bursera filicifolia

3. Leaflets sparsely pubescent or glabrate beneath, or pubescent only

along the costa...... 4

4(3). Leaflets 4-8 cm. long, strongly toothed, the apex acuminate . . .

...... *Bursera penicillata

4. Leaflets most of them less than 1 cm. long, very coarsely crenate or

rarely entire, the apex rounded to acute . . . Bursera laxiflora

5(1). Petiole and rachis wingless; leaflets entire, relatively large,

4-10 cm. long...... 6

5. Petiole and rachis usually slightly winged; leaflets serrate-crenate

or if entire, much smaller (1-2.5 cm. long or less)...... 7

6(5). Fruit and ovary densely pubescent; leaflets usually 5 ......

...... Bursera grandiflora 134

6. Fruit and ovary glabrous; leaflets usually 2-4 pairs 0

e e o o .... o . e o o ... . Bursera arborea

7(5). Leaflets 3-5> finely but conspicuously crenate-serrate3 2-6 cirio

long; fruit not wrinkled ...... ^Bursera lancifolia

7. Leaflets 5-9, entire or obscurely dentate or crenate, l*5-2,5 cm.

long; fruit wrinkled ...... Bursera confusa

41. MELIACEAE. Mahogany Family

. ,1 o Trichilia

1. Leaflets 5-12 cm. long; veIvety-tomentose beneath; capsules usually

2-valved, the valves at least as broad as long; anthers glabrous

...... Trichilia colimana r

1. Leaflets 2.5-8 cm. long, tomentulose beneath along the midrib and

lateral veins, or glabrous; capsules usually 3-valved, the

valves longer than broad; anthers pubescent. . . Trichilia hirta

42. MALPIGHIACEAEo Malpighia Family

1. Receptacle flat or depressed; fruit a capsule or drupe, never

bristly...... - 2

1. Receptacle high, usually pyramidal; fruit of winged samaras or

nutlike, or densely bristly...... 4

2(1). Fruit separating into 3 carpels or capsules; calyx glandless. . .

...... 8. Thryallis p. 136

2. Fruit a drupe; calyx bearing glands...... 3

3(2). Styles united; flowers in panicles. 1. Bunchosia p. 135

3. Styles distinct; flowers in peduncled axillary contracted cymes. . .

...... 6. Malpighia p. 135 135

4(1) . Fruit densely bristly . „ . . . . o . • , » .2. Echinopterys p , 135

4 o Fruit not bristly, usually of samaras«, «••• e '.5

5(4). Samaras with lateral wings 9 these united e ...... e « <> 6

5 o Samaras with a single dorsal w i n g ...... 7

6(5)o Fertile stamens 10; styles distinct; samaras rounded at the base^

...... , . 7. Mascagnia Po 135 .

6. Fertile stamens 3; styles usually united; samaras mucronate at the

base o »3. Guadichaudia po 135

7(5). Fertile stamens 10; styles 3, distinct. . .4. Heteropteris p. 135

7. Fertile stamens never 10; styles united...... 5. Janusia p. 135

I. Bunchosia

One species...... o e .... Bunchosia sonorensis

2. Echinopterys

One species...... ' . . . . . • . . 0Echinopterys eglandulosa

3. Guadichaudia

One species o . . . . o ...... Guadichaudia. mucronata

4. Heteropteris

One species...... „ ...... Heteropteris palmer!

5. Janusia

1. Leavesbroad, elliptic or ovate; larger petals 5-6 mm. long» .

„ e „ e „ 0 . o o . . . Janus ia californica

1. Leaves narrowly linear; larger petals 3-5 mm. long ......

„ e » „ ...... o . .. . o . ;■...... Janusia 1inearis

6. Halpighia

One species...... Malpighia umbellata 136

7. Mascagnia

One species...... oMascagnia macroptera

8. Thryallis

1. Ovary glabrous; leaf blades oblong, ovate or oval. .Thryallis glauca

1o Ovary pubescent; leaf blades linear to linear-lanceolate ...... 2

2(1)o Leaves and sepals densely silky-strigose; larger petals 11-12 mm.

long, apiculate...... , . . Thryallis vestida.

2. Leaves and petals glabrous; larger petals 4-5 mm. long, not

apiculate...... Thryallis angustifolia

43. POLYGALACEAE. Milkwort Family

1. Ovary and fruit 1-celled; fruit indehiscent, samaroid or drupaceous

...... 1. Monnina p. 136

1. Ovary and fruit 2-celled; fruit a flat, dehiscent capsule......

...... 2 . Polygala p. 136

1. Monnina

1. Plants annual; leaves very narrowly lanceolate; fruit samaroid;

stamens 6...... Monnina wrightii

1. Plants suffrutescent; leaves elliptic to lance-elliptic; fruit

drupaceous; stamens 8...... Monnina schlechtehdaliana

2. Polygala (7)

1. Keel without a crest or beak; leaves more or less dimorphous, the

lower oval or oblong-oval, the upper considerably longer, oblong

to linear; sepals and wings quickly deciduous. *Polygala obscura

1 o Keel with a fimbriate crest. 2 137

2(1). Capsule with a broad scarious wing on the upper cell; leaves all

alternate e . . .. „ «, «, . • « . . « . * . Polygala hemipterocarpa

2. Capsule not winged, at most narrowly margined on both cells; leaves

(at least the lowest) often in whorls« • ., . . . ; . » » o « » 3

3(2), Plants annual; stems not rushlike, freely branched above the

base, not more than 30 cm* long; flowers in racemes; hairs of

seed glochidiate ...... Polygala glochidiata

3. Plants perennial; stems rushlike, often with a cluster of short

leafy branches at base; flowers in spike-like racemes; hairs of

seed not glochidiate Polygala alba

44. EUPHORBIACEAEe Spurge Family (160)

1. Ovules 2 in each cell of the ovary; sap never milky; leaves not

glandular: Sub-family Phyllanthoideae. • • « » o «, . «, 2

1. Ovule 1 in each cell of the ovary; sap often milky or colored;

leaves sometimes with petiolar or laminar,glands: Sub-family

C.rotonoideae » . . . « . » . . * . . « « ® ® . © . 3

2(1). Disc in male flowers intrastamina!, at least in part; fruit in-

dehiscent, seeds one per locule. © ...... 4. Drypetes,p© 140

2. Disc in male flowers extrastaminal; fruit dehiscent, or at least

with more than 1 seed. © . . © . . . . , . 9. Phyllanthus p © 144

3(2). Flowers surrounded by involucre; both staminate and pistillate

in same involucre. . © © * ...... * ...... 4

3. Flowers not involucrate. . . . © ...... 5

4(3)o Cyathia more or less actinomorphic, often bearing petal-like

on buter margins of glands. . . .5. Euphorbia p. 140 138

4. Cyathia zygomorphic, without appendages„ . . . 8* Pedilanthus p. 144

5(3). Stamens in bud bent inward, the apex of the anther turned down­

ward; flowers usually with petals, mostly in terminal racemes <, *

...... 2. Croton p 0 139

5. Stamens straight in bud, the apex of the anthers turned upward » o 6

6(5). Flowers in dichotomous cymes. . . . * * * . . .6. Jatropha p. 143

6. Flowers variously arranged, never in dichotomous cymes . . •- » . * 7

7(6). Leaves deeply lobed; male disc intrastaminal; calyx lobes imbri­

cate in bud...... o . 7. Manihot p e 144

7. Leaves entire or dentate, not deeply lobed ...... * . . . 8

8(7). Segments of the staminate calyx valvate in bud...... 9

8. Segments of the staminate calyx imbricate in bud . * ...... 11

9(8)o Petals present, at least in male flowers; seeds ecarunculate. . «

o „ ...... o o . o .... c . 3. Ditaxis p. 140

9 o Petals absent in both staminate and pistillate flowers; seeds

carunculate or not ...... o . .10

10(9). Styles distinct; stinging hairs absent; seeds usually caruncu­

late ...... 1. Acalypha p. 138

10. Styles united; stinging hairs usually present; seeds not caruncu­

late ...... 12. Tragia p. 145

11(10)o Seeds carunculate, dry; fruit capsular. .11. Sebastiania p. 145

11. Seeds ecarunculate, either seed coat or carpel wall fleshy. . . . .

...... 10. Sapium p. 144

1. Acalypha

1. Herbaceous p l a n t s ...... 2

1. Shrubby or fruticose plants...... 4 139

2(1). Stems fleshy and fistulous9 glabrous at maturity; pistillate

bracts 9-11 parted nearly to the base, these only sparsely

stipitate glandular; ovary glabrous. . . . .Acalypha polystachya

2. Stems not fleshy nor fistulous, usually pubescent; pistillate bracts

3-9 parted, glabrous or long pilose and glandular; ovary

pubescent. . . „ o ...... 3

3(2). Pistillate bracts 3-5 lobed, these long pilose and glandular. «

o o ...... oo.o. .Acalypha alopecuroides

3. Pistillate bracts 7-9 lobed, these glabrous or essentially so on

back, short ciliolate along margins. . . . .Acalypha neomexicana

4(1). Stems and petioles not stipitate glandular. . . .Acalypha gentry!

4. Stems and petioles stipitate glandular ...... ;. » * 5

5(4). Pistillate bracts 08-15 parted, styles subpalmately 3-7 lacinu-

late .0000.00 ...... o.oo. .Acalypha sub-viscida

5. Pistillate bracts 19-23 parted; styles pectinately 11-15 lacinulate.

o . . . o . o . o 'o o . o . o...... Acalypha adenostachya

2. Croton

1 o Plants dioecious .o ...... o . . . . Croton californicus

1. Plants monoecious...... 2-

2(1). Leaf margins and the minute stipules devoid of glands ......

...... , Croton fragilis

2. Leaf margins and the obvious laciniate stipules bearing stipitate

glands . o . o o ...... o . . « 3

3(2). Leaves ovate-lanceolate to broadly ovate, acute to acuminate at

apex ...... Croton ciliato-glanduliferum 140

3 o Leaves lanceolate, blunty rounded and mucronate at apex, ......

Croton subjucunHus

3- Ditaxis

1 o Gland tipped fimbriae present on the leaves, bracts and pistillate

sepals . , . , , , , , .Ditaxis adenophora

1. Gland tipped fimbriae lacking...... , . o 2

2(1). Leaves linear-lanceolate to narrowly elliptic; staminodia none

or minute, . .Ditaxis lanceolate

2, Leaves mostly ovate to ovate-lanceolate; staminodia well developed,

usually 3-5 * . Ditaxis tinetoria

4. Drypetes

One species Drypetes lateriflora

5. Euphorbia

1 o Glands of the cyathium without petaloid appendages, either deeply

cupped or concealed by the inflexed linear segments of the

margins; seeds carunculate: Sub-genus Poinsettia ...... 2

1. Glands of the cyathium with petaloid or fimbriate appendages (if

lacking, then the leaves strictly opposite); seeds not

carunculate , . . „ , ® 4

2(1). Plants perennial from thickened storage roots .Euphorbia colorata

2. Plants annual, without thickened storage roots 3

3(2). Leaves all opposite or essentially so; seeds 2.6-2.8 (-3.1) mm.

long; glands stipitate, more or less bilabiate, the opening

narrowly oblong...... ^Euphorbia dentata var. cuphosperma

3. Leaves alternate between the basal pair and the floral whorls;

seeds 3-3.5 mm. long; glands sessile or essentially so, more 141

or less funnel-like3 the opening circular* 0 •

* . * . • • * ••*... * ...... Euphorbia heterophylla

4(1). Leaves alternate, opposite, or whorled, symmetric at base; stip­

ules absent or gland like: Sub-genus Agaloma...... * 5

4. Leaves all strictly opposite, usually inequilateral at base; stip­

ules mostly well developed: Sub-genus Chamaesyce * » * <, • * *10

5 (4) . Shrubs • » 6

5. Herbs...... » . » 7

6(5). Glands distinctly plicate tangential to involucral rim, inner

lobe shorter than outer; leaves usually obtuse to emarginate, .

broadest at distal end, midrib very prominent beneath. . . . « »

.. o o . . o . Euphorbia plicata

6 . Glands not plicate, usually cupped, outer and inner parts alike;

leaves acute, midrib less conspicuous beneath......

...... ooooooooooo. .Euphorbia colletioides

7(5). Annual herbs. 8

7. Perennial herbs...... o ...... o ... 9

8(7). Glands 4, elliptical, with purple appendages; capsule villous . .

...... o . o . oo.oo... .Euphorbia subreniforme

8 . Gland solitary, reniform, with a white appendage; capsule smooth . .

...... o ...... Euphorbia uniglandulosa

9(7). Plant with a tuberous root. . . » ...... Euphorbia plummerae

9. Plant without a tuberous root. . . e . . . . . » .Euphorbia graminea

10(4). Leaves strictly e n t i r e ...... * o. . . * .11

10. Leaves not strictly entire, at least some of them serrulate or

crenulate in part...... •.•.•..•••^..14 142

11(10). Appendages none on involucral glands. . . . Euphorbia petrlna

11. Appendages present on, at least, some of involucral glands on each

cyathium ...... » . o ...... 12

12(11). Leaves, stems, involucres, and capsules glabrous......

...... Euphorbia gracillima

12. Leaves, stems, involucres, and capsules usually pubescent „ . . .13

13(12). Involucre urceolate to long turbinate, constricted above. . <>

...... Euphorbia arizonica

13. Involucre campanulate, not constricted above.Euphorbia pediculifera

14(10). Capsules pubescent. ^ . .15

14. Capsules glabrous...... 19

15 (14). Cyathia in peduncled glomerules ....o...... 16

15. Cyathia not in peduncled glomerules ...... 17

16(15). Perennial plants; involucres often rather crowded on short

branches ...... 4-Euphorbia capitellata

16. Annual plants; involucres usually not crowded . . . Euphorbia hirta

17(15). Appendages of glands greatly unequal in size, one pair longer ;

than the other; capsule fully exserted and nutant at maturity,

often concealed by the longer appendages . .Euphorbia adenoptera

17. Appendages of glands subequal in size, often much reduced, or if

two appendages much longer than other two, capsule not fully

exserted, splitting one side of cyathium at maturity . . . / .18

18(17). Annual plant; stems mostly erect; staminate flowers 5-11 per

cyathium; seeds ovoid-subquadrangular, 1.1-1.6 mm. long, 0.9-

1.1 mm. tangentially and radially...... Euphorbia maculata 143

18e Short lived perennial plant; stems prostrate; staminate flowers 3-

5 per cyathium; seeds sharply quadrangular, 0 .8-0 .9 mm.'-long.,

0.45-0.55 mm. tangentially and radially. . .Euphorbia thimifolia

19(14). Perennial plants. . .20 *

19. Annual plants ...... 21

20(19). Cyathia borne in dense cymose glomerules, or a few solitary in

the upper bifurcations; stipules 0.5-1 mm. long. , ...... «

...... Euphorbia villifera

20. Cyathia solitary at the nodes and terminal; stipules 1.5-2 mm.

l o n g ...... 4-Euphorbia capitellata

21(19). Capsules 3-3.4 mm. long; appendages about half as wide as to a .

little wider than the glands ...... Euphorbia trachysperma

21. Capsules less than 3 mm. long ..... 6 « .22

22(21). Leaves linear, symmetrical, with sharp discrete serrulations;

seeds subalately angled...... Euphorbia florida

22. Leaves and seeds not as above ...... 23

23(22). Leaf blades (the longer ones) considerably more than 15 mm.

long, the margins usually serrulate. . . .Euphorbia hyssopifolia

23. Leaf blades (the longer ones) less than 15 mm. long, the margins

, serrulate only near apex * ...... 24

24(23). Stems and leaves densely hirsute with long, rather stiff

spreading hairs...... Euphorbia villifera

24. Stems and leaves usually glabrous ...... Euphorbia cumbrae

6 . Jatropha

1. Leaves shallowly 3-5 lobed ...... Jatropha platanlfolia

1. Leaves entire or dentate, but not markedly lobed ...... 2 144

2(1). Pistillate sepals and leaf margins not glandular.Jatropha cinerea

2 o Pistillate sepals and leaf margins glandular...... 3

3(2). Plant a low, openly branched shrub less than 2 m. tall; spur

branches conspicuously much roughened by old leaf bases; glands

on leaf margins sessile or essentially so. Jatropha cardiophylla

3. Plants more or less arborescent, 2-6 m. tall; spur branches lacking

or less conspicuous, moderately roughened when present; glands

on leaf margins stalked or sessile ...... Jatropha cordata

7. Manihot

1. Lobes of leaves lobed at or below the middle . . Manihot angustiloba

1. Lobes of leaves e n t i r e ...... ® ...... 2 ,

2(1). Lobes linear, mostly 4-9 mm. wide « o ......

...... ^Manihot rubricaulis subsp. isoloba

2. Lobes lanceolate, mostly more than 10 mm. wide . . ^Manihot davisiae

8. Pedilanthus (85)

1. Colored floral bracts conspicuous, exceeding the inflorescence «, . .

...... Pedilanthus rubescens

1. Colored floral bracts wanting...... Pedilanthus macrocarpus

9. Phyllanthus (161)

1. Plants herbaceous; leaf blades narrowly oblong to obovate, mostly

5-10 mm. long, 1.5-5 mm. broad .... .Phyllanthus polygonoides

1. Plants shrubby; leaf blades orbicular to rounded elliptic or ovate-

orbicular, mostly 1.5-3 cm. long, 2-3 cm. broad......

...... o ...... Phyllanthus micrandus

10. Sapium

One species „ . Sapium appendiculaturn 145

llo Sebastiania

One species...... - . ^Sebastiania pavoniana

12. Traeia (84)

One species o ...... * , . . , Tragia nepetifolia

45. ANACARDIACEAEo Cashew Family

1. Stamens 10, twice the number of petals . . « . . .2. Spondias p» 145

1. Stamens 5, equal in number to the petals ...... 2

2(1) . Drupe red, pubescence of glandular hairs; mesocarp non-waxy

...... o - . o o e . . .1. Rhus p. 145

2. Drupes* whitish, glabrous (if pubescent, not glandular); mesocarp

ceriferous ...... 3. Toxicodendron p»

1 © Rhus (3)

1 e Flowers usually appearing before the leaves; deciduous shrub,

scandent ...... Rhus allophylloides

1 . Flowers usually appearing with the leaves; evergreen shrub or small

tree ...... 2

2(1). Axillary inflorescences not surpassed by the subtending leaves;

leaves thin-coriaceous; inflorescence with many loose, slender,

lateral spikes ...... Rhus hartmannii

2. Axillary inflorescences surpassed by the subtending leaves; leaves

coriaceous; inflorescences few, contracted, usually lateral

stout spikes ...... Rhus tepetate

2. Spondias

One species...... Spondias purpurea 146

3. Toxicodendron 4 One species...... Toxicodendron diversiloba

46. AQUIFOLIACEAEo Holly Family

1 o Ilex

1. Flowers solitary in the leaf axils; teeth of the leaves usually with

spinulose tips ...... Ilex rubra

1 . Flowers fasciculate in the leaf axils; teeth of the leaves without

spinulose tips ...... Ilex tolucana

47. CELASTRACEAE. Staff-tree Family

1. Fruit a dehiscent capsule...... 1. Maytenus p. 146

1. Fruit samaroid, bearing 3 broad longitudinal wings •

. . 2 . Wimmeria p . 146

1. Maytenus

One species...... * ..... o. ... . Maytenus phyllanthoides

2 . Wimmeria

One species...... Wimmeria mexicana

48. ACERACEAE. Maple Family

1 o Acer

One species...... Acer grandidentatum

49. SAPINDACEAE. Soapberry Family

1. Plants scandent, usually with tendrils; flowers irregular; stamens

8, excentric; leaves odd-pinnate ...... 2

1. Plants erect, never with tendrils; flowers regular; stamens 5-10,

attached centrally; leaves simple or even-pinnate...... 3 147

2(1). Fruit of 3 samaras, the seeds borne at the apex ......

...... 4o Serjania p . 147

2 e Fruit capsular, dehiscent...... 1. Cardiospermum p. 147

3(1). . Leaves pinnate with numerous leaflets, not viscid; flowers in

large terminal panicles; petals present;fruit fleshy, not

w i n g e d ...... 3. Sapindus p. 147

3. Leaves simple, viscid when young; flowers in small lateral clusters;,

petals lacking; fruit a septicidal capsule, winged ......

...... 2 . Dodonaea p. 147

1 o Cardiospermum

One species...... Cardiospermum halicacabum

2. Dodonaea

One species...... Dodonaea viscosa

3. Sapindus

One species...... Sapindus saponaria

4. Serjania

1. Cells of the fruit lenticular; fruit 2-2.5 cm. long, commonly

glabrous ...... Serjania mexicana

1. Cells of the fruit inflated, more or less produced beyond the axis;

fruit 1.5-2 cm. long, puberulent ...... Serjania palmeri

50. RHAMNACEAEo Buckthorn Family

1. Plants with tendrils; ovary inferior; fruit 3~valved ......

...... 5. Gouania p. 149

1. Plants without tendrils; ovary superior; fruit not winged. . . . . 2

2(1). Fruit drupaceous with a single stone, this 1-3 celled ..... 3 148

2. Fruit capsular or drupaceous, but containing 2-4 or only slightly

coherent stones...... ••.••••5

3(2)e Branches not spine-tipped; each cell of the ovary 2-ovuled9 one

often abortive; leaves ample, not fasciculate, .• . • » 0 . •

...... 6 Karwinskia p. 149

3. Branches spine-tipped; each cell of the ovary 1-ovules; leaves small

usually fasciculateo • • • ...... * . . * . . . . « . * 4

4(3). Petals n o n e ...... 3. Condalia p. 149

4. Petals present ...... „ ...... 4. Condaliopsis p. 149

5(2). Ovary wholly superior, free from the calyx; fruit drupelike,

more or less fleshy, the cells indehiscent . . 7. Rhamnus p. 149

5. Ovary partly inferior, adnate below to the calyx; fruit capsule­

like, dry at maturity, the cells dehiscent...... * . . 6

6(5). Calyx lobes not petaloid; petals greenish or yellowish. . . . . „

. . e ^ . e o o o « c . . . . 2. Colubrina p. 149

6. Calyx lobes petaloid; petalswhite, bluish or lavender ......

...... 1. Ceanothus p . 148

1. Ceanothus (79)

1, Plants with spinose branchlets ...... Ceanothus depressus

1. Plants never spiny ...... 2

2(1). Leaves 3-veined from the base, ovate-lanceolate to oblong-

lanceolate, mostly 3-8 cm. long...... Ceanothus coeruleus

2. Leaves normally 1-veined from the base, with secondary veins arising

laterally and alternately from the main vein on either side,

elliptical or oblong-elliptical, mostly 1-2 cm. long ......

6 . . . e ..... o ...... Ceanothus ochracea 149

2. Colubrina

One species. . . ,

3. Condalia (56)

One species. . . «

4. Condaliopsis

One species. . . < . ^Condaliopsis lycioides

5. Gouania

One species. . . <

6. Karwinskia

One species. « . Karwinskia humboldtiana

7. Rhamnus (166)

1. Flowers borne in peduncled umbels. . . . .

1. Flowers borne in sessile umbels, geminate or solitary„ ...... 2

2(1). Flowers borne in sessile umbels; petals present; leaf blades

mostly 3-5 cm. long, the apex usually obtuse . Rhamnus mucronata

2. Flowers geminate or solitary; not in sessile umbels; petals none;

leaf blades mostly 5-11 cm. long, the apex acute or acuminate. .

...... Rhamnus pinetorum

51. VXTACEAE * Grape Family

1. Petals coherent and deciduous as a c u p ...... 3. Vitis p. 150

1. Petals distinct, spreading ...... 2

2(1). Flowers 4-merous; disk 4-lobate; leaves simple or 5-foliolate . .

...... 2 . Cissus p. 150

2. Flowers 5-merous; disk 5-lobate; leaves simple . .... o » .

...... 1. Ampelocissus. p. 150 150

1. Ampelocissus

One species. Ampelocissus acapulcensis

2. Cissus

1 o Leaves simple9 usually oblong-ovate to rounded«ovate, not lobed* . •

» o o Cissus sicyoides lo Leaves digitate, usually divided into 5 linear-lanceolate lobes * . «

,o»...... o...... oCissus mayoensis

3. Vitis

One species - . . . . . 6 ...... Vitis arizonica

52 o TILLACEAEo Linden Family lo Peduncle adnate to a bract; fruit nutlike ...... 3. Tilia p » 151

1. Peduncle not adnate to a bract; fruit not nutlike...... 2

2(1). Fruit unarmed o. 1. Corchorus p 150

2 o Fruit armed with spines or bristles. . . 3

3(2). Fruit compressed, the margins plumose-hairy ......

...... o . .... o ...... 2 . Heliocarpus p 150

3. Fruit not compressed, all sides covered by bristles......

...... o . o . . . o ...... o o . .4. Triumffeta p 151

1. Corchorus

One species...... Corchorus orinocensis

2. Heliocarpus (159)

1. Lower surface of leaves glabrous or nearly so; stamens about 40* . .

o o ...... Heliocarpus polyandrus

1. Lower surface of leaves densely stellate-tomentose; stamens about

20 .. . . o ...... Heliocarpus reticulatus , 151

3. Tilia

One species...... e . . Tiliafloridana

4. Triumffeta (71)

1. Hyaline spinules of ovary straight, in fruit slightly deflexed;

fruit 4-loculed...... Triucnffeta goldmanii

1. Hyaline spinules of ovary and fruit arcuately recurved; fruit 3-

loculed...... 2

2(1). Spines retrorsely pilosulose; sepals at anthesis 6-10 mm. long. .

...... Triumffeta semi triloba

2 o Spines lightly pubescent; sepals at anthesis 18-30 mm. long. . . . 3

3(2). Sepals about 18 mm. long; fruit easily dehiscent, each cell 2-

seeded ...... Triumffeta discolor

3. Sepals 25-30 mm. long; fruit indehiscent, each cell 1-seeded ....

...... Triumf feta chihuahuensis

53. MALVACEAE» (60) . Mallow Family

1. Fruit a capsule, the carpels not separating at maturity from one

another or from the axis; stamen tube not filamentiferous at

the apex, usually dentate or lobed . . « ...... 2

1. Fruit not capsular, the carpels separating from one another and

from' the axis at maturity; stamen tube filamentiferous at and

often also below the a p e x ...... 3

2(1). Cells of the fruit 1-seeded, these ascending; capsule depressed,

saliently 5-angled ...... 6 . Kosteletzkya p. 155

2. Cells of the fruit 3- to many seeded; capsule not depressed, or if

slightly so, then not saliently angled . . . .5. Hibiscus p c 154 152

3(1). Style branches fiJ* form, introrsely papillate; petals purple,

rarely white, about 1.5 cm. long; involucel none; herbaceous

perennial 9 „ Sidalcea p . 156

3. Style branches terminating in a capitate or truncate stigma. . .» . 4

4(3). Ovules normally two or more in each carpel; seeds 1- to several .

...... o ...... 5

4c Ovules normally solitary in each carpel; seeds 1 ..... o.* . i 8

5(4). Involucel present, compound of 3 bracteoles; carpels reticulated

laterally below but not winged dorsally. .10. Sphaeralcea p, 156

5. Involucel none; carpels normally smooth on lateral walls . . . » . 6

6(5)o Carpels falsely 2-celled by intruding lateral constrictions;

fruit mostly S^carpellate...... 11. Wissadula p. 156

6 . Carpels not falsely 2-celled; fruit not from 3 carpels ...... 7

7(6). Carpels greatly inflated, rounded and muticous at apex, the

walls thin and papery; fruit globose . . .4. Herissantia p. 154

7. Carpels not inflated, commonly more or less pointed at apex and

mucronate to rostrate or aristate, the walls firm, membranous

to coriaceous; fruit truncate-cylindric or ovoid ......

o ...... 1. Ab util on p » 153

8(4). Involucel present; ovule erect or ascending .7. Malvastrum p.. 155

8 . Involucel none; ovules pendulous ...... 9

9(8). Fruit a loculicidal 5- 8-celled capsule . . . 3. Bastardia p. 154

9. Fruit of 5 or more carpels, these separating at maturity .... .10

10(9), Fruit depressed, much broader than high; lateral walls of

carpels fragile, soon disappearing, or becoming lacerate; seeds ( ■ 153

usually enveloped in a loose coat formed by inner wall of

carpel o o ••••.•• 2 , Anoda p • 154

10o "Fruit not depressed, usually about as high as broad; lateral walls

of the carpels firm, persistent; seeds without an aril-like

envelope...... 8. Sida p. 155

1. Abutilon (61)

1. Carpels normally 5 (or rarely 6 in A . incanum), number of ovules

per carpel not more than 3 ...... » > „ « » 2

1 o...... Carpels more than 5 ...... 3

2(1). Stems and branches trigonous; leaves long-acuminate; petals about

5 mm. long; carpels short-beaked...... Abutilon trisulcatum

2. Stems and branches usually terete; leaves acute to short-acuminate;

petals 6-10 mm. long; carpels not beaked, usually rounded at

a p e x ...... Abutilon incanum

3(1). Fruiting calyx not more than 2/3 as long as the mature fruit „ . 4

3 o Fruiting calyx from more than 2/3 as long as to longer than the

mature f r u i t ...... 5

4(3). Larger leaves usually 10-18 cm. long; carpels 8-10 mm* long, 7-11

in number, very shortly or not at all beaked . .Abutilon sonorae

4 o Larger leaves rarely over 9 cm* long; carpels 6-8 mm. long, 5-7 in

number, the beak long...... Abutilon umbellaturn

5(3). Calyx lobes sub-cordate and overlapping at base, at least in the

bud, petals 10-15 mm. long; flowers axillary . Abutilon llgnosum

5. Calyx lobes not sub-cordate; petals about 8 mm. long; flowers in

subumbellate, axillary and terminal clusters ......

. ... o . . . . . o ...... * Abutilon umbellaturn 154

2 o Anoda

1. Carpels normally 5, slightly and bluntly beaked at the apex. » . . „

...... Anoda caudatifolia

1. Carpels more than 5...... 2

2(1). Fruit flattened, disk-like...... 3

2. Fruit hemispheric or somewhat lower, but not flat and disk-like. . 4

3(2). Carpels of the fruit not at all rostrate dorsally or apically,

or with only a small short tubercle...... Anoda acerifolia

3. Carpels of the fruit with a rather long, spreading horizontal beak,

at or near the apex...... *Anoda cristata

4(2). Inner layer of the carpel wall separating from the outer at

maturity as a reticulate, loose, saclike envelope of the seed;

petals yellow to orange...... Anoda crenatiflora

4b Inner layer not separating, or if so, then becoming closely adherent

to the seed and arilliform; petals purple. . . . .Anoda thurberi

3. Bastardia 5

One species...... Bastardia violacea

4o Herissantia (13)

One species...... ^Herissantia crispa

5. Hibiscus (62)

1. Stems finely pubescent in 1 or 2 lines, also hispid with long,

simple, or forked hairs; upper leaf blades deeply lobed; petals

large, 3-4 cm. long, cream-yellow; capsules glabrous ......

...... Hibiscus biseptus

1. Stems glabrous, or sparsely pubescent with stiff, appressed forked

’hairs; upper leaf blades not deeply lobed, usually deltoid-ovate 155

or deltoid-lanceolate; petals smaller, 1.0-2.0 cm. long, normal**

ly purplish or crimson; capsules strigose. Hibiscus brasiliensis

6 . Kosteletzkya

1. Carpels glabrate on back, hispid on angles; leaves mostly 3-lobed. »

o . » o o o o o . o o » . o o . . c o o . Kosteletzkya thurberi

1 o Carpels densely stellate-puberulent on backs as well as hispid on

angles; leaves broadly ovate, not lobed, or basal ones shallow**0

ly 3-lobed . . * ...... « Kosteletzkya malvaviscana

7 o Malvastrum

One species. . . . . * . . * Malvastrum bicuspidatum

8 c Sida

1. Calyx terete, not angulate ...... 2

1. Calyx conspicuously angulate » ...... e « ’• « . .... 3

2(1). Leaves entire, linear; carpels 7-9, usually glabrous; inflores­

cence a terminal corymb; plants annual or biennial ...... o

o . e o o .. o o o...... Sida linifolia

2 o Leaves serrate, although obscurely; carpels 5, usually pubescent;

inflorescence racemose-paniculate; plants perennial. . . o , . .

...... Sida lodiegensis

3(1). Carpels 7-14. . . o. . . . o ...... 4

3. Carpels 5, sometimes 6 ...... 6

4(3). Leaves, or most of them, distinctly cordate at base, velvety on

both surfaces; larger leaves over 3 cm. wide . . Sida cordifolia

4. Leaves cuneate, or rounded to sub-cordate at base, never velutinous;

larger leaves seldom 3 cm. wide. . „ ...... 5 156

5(4). Calyx 5~angulate in bud; stems and petioles hirsute with spread­

ing simple hairs extending beyond stellate puberulence » . . . „

oooo.ooo. oSida tragiifolia

5. Calyx 10-angulate in bud; stems and petioles appressed stellate-

puberulent, not hirsute. . e Sida rhomb if olia

6(3). Leaves mostly 2 cm. long or less, the apex rounded or obtuse;

stems procumbent . . » ...... Sida procumbens

6 . Leaves mostly much more than 2 cm. long, the apex acuminate. . . . 7

7(6). Pedicels and upper parts of stems viscid-pilose; sepals sparingly

hirsute and glandular-puberulent ...... Sida glutinosa

7. Pedicels and upper parts of stems without any viscid-pubescence;

sepals nearly glabrous e - Sida glabra

9 o Sidalcea (128)

One species...... • ...... Sidalcea neomexicana

10 o Sphaeralcea (59)

1. Leaf blades about as wide as long, the apex usually obtuse., the

base more or less cordate, distinctly 3-lobed. „ . . . . . „ .

o.o...... Sphaeralcea coulteri

1. Leaf blades commonly longer than wide, the apex acute or acutish,

the base usually subcuneate or truncate, shallowly lobed or

merely angled...... Sphaeralcea coulteri vaf. californica

11. Wissadula

1. Leaves entire, mostly 5-15 cm. long; petals normally yellow. . . . .

...... «... .Wissadula amplissima

1 Leaves crenate-dentate, mostly 1-2.5 cm. long; petals normally

purplish, at least when dry. .Wissadula cincta 157

54. BOMBACACEAE; Bombax Family

1. Stamen tube short, giving rise to many simple filaments; trunk

unarmed; leaflets entire •••••••.••• *1• Bombax p. 157

1. Stamen tube longer, dividing into 5 parts, each of these bearing

several sessile anthers at its summit; trunk often spiny;

leaflets entire to serrate-dentate * ...... 2. Ceiba p. 157

1 o Bombax

One species...... Bombax palmeri

2 . Oeiba

One species...... Ceiba acuminata

55. STERCULIACEAE. Sterculia Family

1. Petals plane; anthers 5, usually 2-celled...... 2

1. Petals concave or cucullate; anthers 15 or 5 and 3-celled...... 3

2(1). Capsule 1-celled...... 4. Waltheria p. 158

2. Capsule 5-celled ...... 3. Me lochia p. 158

3(1). Capsules chartaceous; petals united at the apex with the stamen

tube; anthers 5 ...... 1. Ayenia p. 157

3. Capsules woody; petals free from the stamen tube; anthers 15,

commonly in 5 groups of 3...... 2. Guazuma p. 158

1 o Ayenia

1. Fruit and ovary long-stipitate, the stipe slender, in fruit 2-3 mm.

long or sometimes longer; calyx lobes ascending or erect, not

reflexed ...... 2

1. Fruit and ovary nearly sessile, the stipe stout, in fruit less than

1.5 mm. long ...... 3 ' 158

2(1) • Capsule merely short tuberculate; papillae mostly about 0.5 mm.

long or less; leaves ovate or broadly ovate. . . Ayenia wright11

2. Capsule sharply muricate; papillae 1-1.4 mm. long or longer; leaves

typically lanceolate, often narrowly s o ...... Ayenia pusilla

3(1). Lower surface of leaves glabrous, or nearly so. . . Ayenia glabra

3 o Lower surface of leaves stellate-tomentose, the hairs loose and

spreading...... Ayenia palmeri

2 . Guazuma

One species...... Guazuma ulmifolia

3. Melochia (34)

One species...... Melochia tomentella

4. Waltheria

1. Calyx lobes much shorter than the tube; petals not exceeding the

calyx...... Waltheria alamosana

1. Calyx lobes as long as or slightly longer than the tube; petals'

longer than calyx...... Waltheria americana

1 56. GUTTIFERAE. Garcinia Family

1o Hypericum

1. Leaves and sepals black-dotted along margins; mature leaves oblong

ovate...... Hypericum formosum

1. Leaves and sepals not black-dotted along margins; mature leaves

linear-subulate or needlelike...... Hypericum pratense

57. FOUQUIERIACEAE. Candlewood Family

1. Fouquieria

One species...... Fouquieria macdougalii 58. CISTACEAEo Rock-rose Family

1. Petals 5, yellow3 longer than the sepals3 stigma typically

capitate; seeds numerous; pubescence completely of stellate

hairs„ ...... -. » . . . » ...... 1, Helianthemum p. 159

1. Petals 3) red3 about equalling or slightly shorter than the sepals;

stigma fimbriate-plumose; seeds usually 63 sometimes 4;

pubescence of simple hairs ...... 2 . Lechea p. 159

1. Helianthemum

One species. e o ...... Helianthemum pringlei

2 o Lechea

One species...... Lechea tripetala

59. COCHLOSPEKMACEAEo Cochlospermum Family

1. Plants trees; fruit globose-obovoidj depressed at apex; seeds

covered with long, shining white hairs . 2. Cochlospermum p. 159

1. Plants herbaceous; fruit ovoid to ellipsoidal, acute at apex; seeds

enclosed by a papery arilloid, this puberulent ...... o .

} ...... o o o o o o ... 1. Amoreuxia p. 159

1. Amoreuxia (144)

One species...... * ...... Amoreuxia palmatifida

2 . Co chlo spermum

One species...... Cochlospermum vitifolium

60. VIOLACEAE. Violet Family

1. Hybanthus (89)

1. Shrub; leaves alternate; flowers on pedicels about 3 mm. wide. . . .

...... Hybanthus mexicanus 160

1. Herbaceous annual; leaves, at least the lowest, opposite; flowers

on pedicels about 2 cm, long , ...... *Hybanthus attenuatus

61. FLACOURTIACEAEo Flacourtia Family

1, Xylosma

One species...... Xylosma flexuosum

62. TURNERACEAE. Turnera Family

1. Turnera

One species, ••••••••••••• « * ...... Turnera ulmifolia

63. PASSIFLORACEAE, Passion-flower Family

1. Passiflora (66)

1, Fruit with denticulate operculum; bracts deeply pinnatisect, the ) - segments filiform, involucrate; leaves 3- 5-lobed; stipules

pinnatisect...... Passiflora foetida

1. Fruit with plicate operculum; bracts linear-subulate or setaceous,

not involucrate; leaves 2 or 3 lobed; stipules linear, linear-

subulate or setaceous, , . . , , , ...... 2

2(1). Leaves deeply 2-lobed; stipules setaceous or narrowly linear,

1.5-2 mm. long; petiolar glands none; seeds transversely sulcate

with 7 or 8 irregular ridges ...... Passiflora mexicana

2. Leaves.3-lobed; stipules linear to linear-subulate, usually more

than 2 mm. long; petiolar glands present; seeds reticulate . . 3

3(2). Corona filaments in 2 series; stipules 6-8 mm. long; petiolar

glands usually less than 0.5 mm. in diameter ......

...... Passiflora suberosa 161

3. Corona filaments in a single series; stipules 3-4 mm. long; petiolar

glands about 1 mm. in diameter ...... Passiflora quercetorum

64. CARICACEAE. Carica Family

1. Jarilla

One species Jarilla chocola

65. LOASACEAE. Loasa Family

1. Ovary containing a singel pendulous ovule; stamens 5 ......

...... 2. Gronovia p. 161

1. Ovary containing several to many ovules, these attached to parietal

placentae; stamens numerous...... 2

2(1). Carpels usually 3; placentas not thick, nor projecting far into

the cavity of the ovary; ovules in 1 or 2 rows on the placentae;

petals 4-8 mm. long...... 3. Mentzelia p. 161

2. Carpels usually 5; placentas thick, more or less circular in cross

section; projecting far into the cavity of the ovary; ovules in

several rows on the placentae; petals about 4 cm. long .....

• 1. Eucnide

One species......

2. Gronovia

One species J . . .

3. Mentzelia (19)

One species...... 66. BEGONIACEAEe Begonia Family

1. Begonia (20)

1. Fruit bearing a single wing, this truncate at the apex ......

...... o o * o * . . .Begonia portillana

1 o Fruit bearing 3 unequal wings, these usually acute at apex .... 2

2(1). Stems pubescent, usually with coarse, somewhat tangled hairs;

leaves pubescent, chiefly beneath along veins, nearly glabrous «,

...... ^Begonia gracilesvar. nervipilosa

: 2. Stems usually glabrous; leaves entirely glabrous on both sides « o <,

...... ^Begonia graciles var. martiana

_ 67. CACTACEAE (12). Cactus Family

1. Vegetative parts bearing leaves; glochids present...... 2

1. Vegetative parts usually not bearing leaves; glochids none .... 4

2(1). Leaves broad and flat ...... 11. Pereskiopsis p. 166

2. Leaves.usually terete...... 3

3(2). Stamens much longer than the petals ...... 8 . Nopalea p. 165

3. Stamens shorter than the petals...... 9. Opuntia p. 165

4 (1). Flowers and spines borne at different areoles; short, one

jointed cacti...... 7. Mammilaria p. 164

4. Flowers and spines borne at the same areoles...... 5

5(4). One-jointed or few-jointed cacti, the joints usually short. . . 6

5. Several-jointed or many-jointed cacti, the joints elongate .... 7

6(5). Flowers at lateral areoles...... 3. Echinocereus p. 164

6 . Flowers at central areoles...... 4. Ferrocactus p. 164 163

7(5). Flowers usually 1 to several at each areole, small ......

...... 6 . Lophocereus p. 164

7 . Flowers solitary at each areole, mostly large...... 8

8(7). Ovary naked or nearly so; ribs 12-14. . .2. Cephalocereus p. 163 •

8. Ovary with scales, often also bearing wool, bristles, or spines. . 9

9(8). Fruit dry, abundantly bristly at maturity; outer perianth seg­

ments purplish, inner white; spines 8-12, grayish with black

tips ...... 10. Pachycereus p. 166

9. Fruit juicy or pulpy, often sparsely spiny to nearly naked at

m a turity...... 10

10(9) . Ribs 8-25...... 11

10. Ribs 4-8...... 12

11(10). Flowers 10-12 cm. long, greenish to nearly white; seeds 0.6-

0.8 mm. long; ribs obtuse; branches 3-6.5 dm. in diameter. . . .

...... 1. Carnegie p . 163

11. Flowers 6-8 cm. long, purplish; seeds 1.5-2 mm. long; ribs rounded;

branches usually less thick than above .5. Lemaireocereus p. 164

12(10). - Roots fleshy and tuberlike; flowers usually white; ribs 4-5 . .

...... 13. Wilcoxia p. 166

12. Roots fibrous or woody, not markedly fleshy and tuberlike; flowers

scarlet; ribs 5 - 8 ...... 12. Rathbunia p. 166

1. Carnegla

One species...... Carnegla gigantea

2. Cephalocereus

One species...... Cephalocereus alensis 164

3 . Echitiocereus

1 e Ribs 14-16 ...... Echinocereus stoloniferus

1• Ribs not more than '••••. .o.0 .o«2

2(1). Ribs 8-9 ...... * . . . Echinocereus luteus

2. Ribs 5 o ...... e . . Echinocereus %entryi

4, Ferrocactus

1 o Giant species, the old plants about 2 m. in height or more; spines

white to reddish . . . ' .■ ...... ' . . Ferrocactus wislizeni

1. Plants much smaller, the old plants rarely exceeding 50 cm. in

height; spines all yellow...... Ferrocactus alamosarius

5 . Lema ireo cer eus

1. Plants with a definite trunk; ribs usually 8; outer perianth seg­

ments purplish . . . o ...... Lemaireocereus montanus

1. Plants without a definite trunk; ribs 12-17; outer perianth

segments reddish ...... Lemaireocereus thurberi

6 . Lophocereus

One species...... o o , Lophocereus schotii

7 . Mammillaria

1. Tubercles with watery sap; seeds usually black ...... » . 2

1. Tubercles with milky sap; seeds usually brown...... 5

2(1). Radial spines usually 10-15 per areole...... 3

2. Radial spines usually more than 15 per areole...... 4

3(2). Stigma lobes purplish; fruit obovoid, 6-8 mm. long......

...... oo.. .Mammillaria mainae

3. Stigma lobes green; fruit clavate, 25-35 mm. long......

* ...... Mammillaria sheldonii 165

4(2) o Axils of tubercles naked; filaments deep pink; radial spines 15=

30, 6-12 mm. long...... Mammillaria micro carpa

4. Axils of tubercles wooly; filaments deep magenta; radial spines 25=

36, 3=6 mm. long ...... Mammiliaria oliviae ' - /■ 5(1). Axils of tubercles only with white bristles £ tubercles terete or

nearly so; central spines 4, radial spines 16. . . . » . . . . .

. o .. o ...... o . o o ...... Mamtni 1 laria standleyi

5. Axils of tubercles with white wool, occasionally a few scattered

hairlike bristles; tubercles usually 4-angled; central spines

1-4, radial spines 7-15...... Mammillaria sonorensis

8. Nopalea

One species o ...... o ...... Nopalea sp»

9 . Opuntia

1. Joints terete, not flattened; tubercles evident, often prominent:

Sub-genus Cylindropuntia 2

1. Joints, at least some of them, flattened; tubercles rarely apparent:

Sub-genus Platyopuntia ...... 3 ' . 2(1). Joints 10-15 mm. in diameter; spines 3-7 per areole, 5-12 mm*

long ...... Opuntia thurberi

2. Joints much thicker, 3-5 cm. in diameter; spines 2-10 per areole,

commonly over 2 cm. l o n g ...... Opuntia mammillata

3(1). Spines usually wanting; sometimes 1 or more appear, then white in

color; flowers orange; stigma lobes white; fruit ovoid . . . « .

...... Opuntia tomentosa 166

3. Spines usually present3 few, rarely as many as 6, dull brown or

horn-colored; flowers at first yellow, but red in age; stigma

lobes yellowish-green; fruit pyriform to short oblong......

. e o ...... e .Opuntia fuliginosa

10. Pachycereus

One species...... 1...... Pachycereus pecten-aboriginum

11. Pereskiopsis

One species...... Pereskiopsis porteri

12. Rathbunia

One species...... Rathbunia alamosensis

13. Wilcoxia

One species...... Wilcoxia mariana

68. .LYTHRACEAE. Loosestrife Family

1. Flowers actinomorphic or nearly so; calyx campanulate; stamens

usually 4 . . . o ...... 2. Rotala p. 167

1. Flowers zygomorphic; calyx tubular, gibbous or calcarate at base;

stamens usually 11 ...... 1 . Cuphea p. 166

1. Cuphea

1. Flowers small, the calyx about 10 mm. or less longannual plants. 2

1 o Flowers large, the calyx usually more than 10 mm. long; perennial, .

or at least biennial plants...... 3

2(1). Flowers evidently terminal; stems densely pilose; leaves mostly

more than 1 cm. long; ovules 3 ...... Cuphea indocta 167

2. Flowers mostly axillary; stems sparsely pilose to sub-glabrous;

leaves mostly less than 4 cm. long; ovules 3-6 . Cuphea wrightii

3(1). Calyx evidently bialate within, 10-24 mm. long, the spur usually

subascending, rarely incurved; petals 6, or rarely 2 ......

...... Cuphea hookeriana

3. Calyx not bialate within, sometimes slightly bicostate; petals 6

or 2 ...... 4

4(3). Petals 2, usually bright red; stems pubescent, but not. of dark

red hairs...... Cuphea llavea

4. . Petals 6, usually purple; stems pubescent, usually of dark red

glandular hairs...... Cuphea lanceolate

69. RHIZOPHORACEAE. Mangrove Family

1. Rhizophora

One species...... Rhizophora mangle

70. MYRTACEAE. Myrtle Family

1. Psidium

One species...... Psidium sartorianum

71. ONAGRACEAE (97). Evening-primrose Family

1. Sepals persistent after’anthesis; hypanthium not prolonged beyond

the ovary...... 3. Ludwigia p. 169

1. Sepals deciduous after anthesis; hypanthium usually prolonged

beyond the ovary ...... 2

2(1). Seeds commonly with a tuft of hairs at the free end, or sub­

terminal ly winged...... 6 . Zauschneria p. 170 168

2 o Seeds naked, neither hairy nor winged o •••••. ..o « •••• 3..

3(2). Fruit embedded - in the stem axis, appearing like a gall-like

swelling of the stem; stigma sub-capitate......

...... 2. Gongylocarpus p. 169

3. Fruit not forming a gall-like swelling in the stem ...... 4

4(3). Stamens 2, one sterile; sepals slightly unequal, all free or

three of them sometimes partially united; disk in hypanthium

semicircular ...... o .. 4. Lopezia p. 169

4. Stamens usually 8; sepals regular and equal; disk in hypanthium

annular...... 5

5(4). Fruit a capsule, dehiscent...... 5. Oenothera p. 169

5. Fruit nut like, indehiscent ...... 1. Gaura p. 168

1. Gaura (94)

1. Capsule narrowed into a distinct and stout stipelike base......

..... o ...... Gaura coccinea

1. Capsules sessile or nearly so, not narrowed into a pedicel-like

base (exceptions may occur in G. gracilis) ® 2

2(1). Petals yellow, aging red, subequal, rhombic, 14-15 mm. long;

hypanthium 25-35 mm. long; sepals 15-18 mm. long ......

...... -Gaura mutahilis

2. Petals pink to rose, or whitish to reddish, 1.5-6 ram. lohg;

hypanthium 1.5-7 mm. long; sepals 1.5-5 mm. long ^ 3

3(2)o Flowers small, the petals 1.5-2 mm. long, the sepals 1.5-3 mm.

long; anthers oval, 1 mm. long; hypanthium and sepals glabrous

to short pubescent ...... Gaura parviflora , 169

3 o Flowers larger, the petals 5-6 mm.'long, the sepals 4-5 mm. long;

anthers linear-oblong, about 2 mm. long; hypanthium and sepals

with short gland tipped hairs. . Gaura gracilis forma glandulosa

2 o Gongylocarpus

One species...... Gongylocarpus rubricaulis

3. Lopezia (96)

One species...... Lopezia gracilis

4. Ludwigia (117)

One species...... -Ludwigia octovalvis subsp. sessiflora

5. Oenothera (95)

1. Stigma discoid, somewhat shallowly 4-lobed; flowers yellow mostly

diurnal: Sub-genus Salpingia . -fOenothera hartwegii var. toumeyi

1. Stigma with 4 linear lobes; flowers white, or rose, or purplish, or

yellow, mostly vespertine...... 2

2(1). Capsule cylindrical, tapering slightly toward apex; seeds mostly

sessile in 2 rows in each locule: Sub-genus Oenothera......

...... ^Oenothera hookeri subsp. hewettii

2. Capsule clavate, distinctly broader near apex than below; seeds

clustered, stalked in more than 2 rows in each locule: Sub-genus

Hartmannia . . . , ...... 3

3(2). Petals rose to reddish violet, 5-10 mm. long; hypanthium 4-8 mm.

long; capsule 3-4 mm. thick (including wings), strigulose, the

wings scarcely 1 mm. wide...... Oenothera rosei

3. Petals white, aging rose, 10-35 mm. long; hypanthium 10-20 mm. long;

capsule 4-8 mm. thick...... 4 170

4(3) . Petals 10-15 mm. long; capsule 4-5 mrru thick the wings 1 mm.

wide; hypanthium more than 10 mm. long . . . Oenothera kunthiana

4. Petals 20-35 mm. long; capsule 6-8 mm. thick5 the wings 2-3 mm.

wide; hypanthium about 10 mm. long .... .Oenothera tetraptera -

6. Zauschneria (43)

One species...... « ^Zauschneria californica subsp. latifolia .

72. ARALIACEAEo Ginseng Family

1 o Petals narrowly imbricate; leaves pinnate; flowers in umbels ....

„ o * .. . .1. Aralia p. 170

1. Petals valvate; leaves simple; flowers capitate. 2. Oreopanax p. 170

1. Aralia

One species...... r ...... Aralia humilis

2. Oreopanax

One species. .Oreopanax peltatum

73. UMBELLIFERAE (77). Carrot Family

1. Inflorescence a dense bracteate head, not distinctly umbellate . . .

o . . . .5. Erynglum p. 171 .

1. Inflorescence a distinct umbel, with evident rays and usually

evident pedicels more or less spreading, never capitate. . . . 2

2(1). Ovary and fruit armed with bristles ...... 3

2 o Ovary and fruit not armed, glabrous ...... 4

3(2). Stems and leaves variously hispid; involucre present, foliaceous;

involucel about equalling the pedicels .... .3. Daucus p. 171

3. Stems and leaves glabrous; involucre wanting; involucel usually

shorter than the pedicels...... 7. Spermolepis p. 172 171

4(2)* Ovary and fruit flattened laterally; ribs of,the fruit not

prominently winged e . o e 5

4» Ovary and fruit flattened dorsally ..e.e» e » • 6

5(4)o Peduncles 8-28 cm. long; flowers golden-yellow; oil-tubes

solitary in the intervals, 2 on the comissure...... *

...... 1. Arracacia po. 171

5. Peduncles 2-7 cm. long, or frequently some umbels sessile; flowers

yellow or purple; oil-tubes several in the intervals on on the .

comissure...... 4. Donnellsmithia p» 171

6(4). Stylopodium lacking; seed face involute; flowers purple o . » . .

...... o . o » o o ...... 6. Prionosciadium p. 172

6. Stylopodium present, conic; seed face plane to slightly concave;

flowers white...... 2. Conioselinum p. 171

1. Arracacia

One species. Arracacia edulis

2 . Conioselinum

One species. * ...... Conioselinum mexicanum

3. Daucus

One species...... Daucus pusillus

4. Donnellsmithia

1. Flowers purple ...... Donnellsmithia peucedanoides var. purpurea

1 „ Flowers y e l l o w ...... Donnellsmithia peucedanoides

5. Eryngium (76)

1. Leaves parallel-veined; plants with a monocotyledonous habit . . . 2

1. Leaves reticulate-veined; plants not monocotyledonoid. . . . . » . 3 172

2(1)„ Leaves entire or nearly so; heads ovoid or ovoid-oblong, about

twice as long as broad ,Eryngium sparganophyllum

2„ Leaves spinose-ciliate; heads ovoid-cylindrical, about as long as

broad» . . . . • ...... Eryngiutn gramineum

3(1) * Heads with a more or less conspicuous coma, o » » ...... 4

3. Heads without a definite coma „ . o 5

4(3). Petiole fistulose, septate; coma of 3-5 subequal, entire or

spinulose-serrate bractlets, 5-15 mm. long; plants perennial . „

. „ . „ .Eryngium phyteumae

4. Petiole neither fistulose nor septate; coma of 1-3 usually entire

bractlets, 2-6 mm. long, or occasionally obsolete; plants

biennial ...... ■ ...... Eryngium beecheyanum

5(3). Stems leafy below the inflorescence; inflorescence paniculately

cymose-branched; bracts linear-lanceolate, yellowish-white

above; biennial plants...... Eryngium beecheyanum

5. Stems few-leaved below the inflorescence; inflorescence sparingly

cymosely-branched; bracts commonly oblong to lanceolate, silvery

above...... Eryngium calaster

6. Prionosciadium

One species...... Prionosciadium madrense

7 . Spertnolepis

One species...... Spertnolepis echinata

74. CORNACEAE. Dogwood Family

1. Flowers perfect, in heads; petals present; style 1; leaves deciduous

...... 1. Cornus p. 173 173

1. Flowers unisexual, in catkin-like racemes; petals absent; styles 2;

leaves persistend . .2. Garry a p. 173

1. Cornus

One" species...... Cornus disciflora

2. Garrya

One species...... Garrya ovata

75. CLETHRACEAE. Pepperbush Family

1. Clethra

One species Clethra lanata

76. PYROLAGEAE. Pyrola Family

1. Plants saprophytic, lacking chlorophyll; leaves reduced to scales;

pollen grains singel ...... - . .2. Monotropa p. 173

1. Plants autotrophic and green, the leaves with well developed blades;

pollen in tetrads...... 1. Chimaphila p. 173

1. Chimaphila

One species .Chimaphila daysistemma

2. Monotropa

One species...... ^Monotropa latisquama.

77.. ERICACEAE (168) . Heath Family.

1. Fruit capsular, surrounded by the fleshy accrescent calyx......

...... 3. Gaultheria p. 174

1. Fruit baccate or drupa c eous.. . « ...... * . . .2

... > 174

2(1). Fruit baccate, only slightly fleshy, the surface granular-

tessellate, glabrous; cells of the ovary several ovuled......

. 1 * Arbutus p. 174

2. Fruit drupaceous, dry, the surface not glandular, glabrous or

glandular-pilose; cells of the ovary 1-ovulate ......

...... 2. Arctostaphylos p. 174

1. Arbutus

One species ...... Arbutus arizonica

2. Arctostaphylos (23)

1. Fruit papilose; leaf blades linear to narrowly oblong; ovary

pubescent ...... Arctostaphylos polifolia

1. Fruit smooth; leaf blades ovate to lanceolate or obovate to ob-

lanceolate; ovary glabrous ...... Arctostaphylos pungens

3. Gaultheria

One species. . .Gaultheria odorata

78. THEOPHRASTACEAE. Joewood Family

1. Jacquinia

One species...... Jacquinia pungens

79. MYRSINACEAE. Myrsine Family

1. Rapanea

One species...... Rapanea ferruginea 175

80. PRIMULACEAE. Primula Family

1. Samolus

1. Leaves crowded near the base of the stem; pedicels bractless,

spreading to ascending, stiffish; corolla 3-4 mm. long; calyx

lobes about equalling the tube ...... Samolus ebracteatus

1. Leaves scattered along the stem; pedicels with a small bract,

spreading; corolla 1.5-2 mm. long; calyx lobes commonly shorter

than the tube...... Samolus floribundus

81. PLUMBAGINACEAE. Leadwort Family

1. Plumbago

One species...... Plumbago scandens

82. SAPOTACEAE. Sapote Family

1. Corolla lobes with a pair of lateral appendages. . 2. Bumelia p. 175

1. Corolla lobes without appendages ...... 2

2(1). Flowers solitary in the leaf axils; sepals usually 6; ovary 10-

12 celled .1. Achras p. 175

2. Flowers fasciculate, usually on old wood; sepals usually 5; ovary

commonly 5 celled...... 3. Slderoxylon p. 175

1. Achras

One species...... Achras zapota

2. Bumelia (16)

One species...... “Bumelia persimilis subsp. subs.essiflora

3. Sideroxylon

One species...... Sideroxylon angustifolium 176

83. EBENACEAEc .Ebony Family

1. Diospyros

One species. . . o ...... Diospyros sonorae

84. LOGANIACEAEo Logania Family

1. Buddleia (100)

1. Flowers distinctly pedicellate, grouped into small dichasial

clusters, fragrant; calyx tube and lobes commonly equal in size;

corolla white; leaves not dimorphic, the blades lanceolate or

oblong-ovate; plants of blackish exfoliating bark...... »

...... o o ...... Buddleia parviflora ") 1. Flowers grouped into sessile or short pedicellate compact capitate

clusters, acrid odor; calyx tube and lobes not equal in size;

corolla greenish-yellow; leaves somewhat dimorphic, the upper

ones lanceolate, the lower ones broadly ovate; plants of

yellowish-brown bark ...... -Buddleia sessiflora

85 . GENTIANACEAE* Gentian Family

1. Corolla salverform, pink; anthers spirally twisted after anthesis. »

o ...... 2. Centaurium p . 177

1. Corolla funnelform or campanulate, not pink; anthers straight after

anthesis ...... 2

2(1). Corolla narrowly funnelform, pale to dark blue; calyx lobes with

green margins...... 3. Gentiane 11a p. 177

2. Corolla campanulate; calyx lobes usually scarious-margined toward

base ...... o ...... o .... 3 177

3(2). Flowers 5-6«merous5 blue or lavender; style elongate; stamens ;

inserted in the corolla throat . » . . - ... .1. Eustoma p. 177

3. Flowers 4-merous, green or greenish-yellow; style none; stamens

inserted at or near the summit of the tube „ . 4. Halenia p. 177

1. Eustoma ^

One species* * . . * . . . * * . . . . Eustoma exaltatum

2. Centaurium

One species...... * * * .^Centaurium exaltatum

3. Gentlane11a (33)

One species...... *Gentianella detonsa subsp. superb a

4. Halenia (1)

1* Spurs present as very small inconspicuous depressions or pro­

trusions near the base of the corolla tube, usually not very

Visible * * . . . * . e e goo e e e e o e « o e e o o o e o © 2

1. Spurs present and very visible * . . . * ...... * 3

2(1). Leaves linear, slender* ..... = . . * . . . . . Halenia brevicornis

2. Leaves ovate to lanceolate, coarse * ...... *

...... Halenia brevicornis var* latifolia

3(1). Spurs spreading to ascending; calyx lobes up to 6 mm. long,

uninervate; filaments slightly obovate ...... Halenia recurva

3. Sprus incurved; calyx lobes 4-12 mm. long, 3-nerved; filaments

linear, slightly uncinate...... Halenia palmeri

86. APOCYNACEAE* Dogbane Family

1. Anthers neither connivent nor agglutinated to the stigma, without

an enlarged sterile connective ...... **...... 2 178

1. Anthers connivent. and agglutinated to the stigma, consisting of

an enlarged sterile connective « v • 0 « « 4

2(1) o Carpels containing 1-4 o v u l e s ...... 5c Vallesia p. 178

2 o Carpels containing numerous ovules « •' e » . » . « „ „ . = » . . . 3

3(2). Calyx bearing squamellae within; follicles 3.5-4e5 cm. long;

seeds with fleshy arils at maturity. c . .4. Stemmadenia p* 178

3. Calyx without squamellae; follicles 9-30 cm. long; seeds not

arillate . „ ...... 3. Plumeria p. 178

4(1). Corolla funnelform, pubescent externally. 1. Macrosiphonia p. 178 •

4. Corolla salverform, glabrous externally...... 2. Vandevilla p. 178

1. Macrosiphonia

1. Leaves oblong to ovate, 10-15 cm. long, 4-8 mm. broad; sepals

triangular-lanceolate, 4-5 mm. long; follicles relatively

slender, about 6.5 cm. long...... Macrosiphonia woodsoniana

I. Leaves narrowly oblong to linear, 2-9 cm. long, 4-22 mm. broad;

sepals oblong-lanceolate 5-10 mm. long; follicles relatively

stout, 9-13 cm. l o n g ...... Macroslphonia hypoleuca

2. Vandevilla (170)

One species. . . . Vandevilla foliosa

3. Plumeria (171)

One species...... o . . Plumeria mollis

4. Stemmadenia (169)

One species...... ^Stemmadenia tomentosa var. palmeri

5. Vallesia

One species...... Vallesia glabra 179

87. ASCLEPIADACEAEe Milkweed Family (172)

1. Pollen granular; corolla funnelform9 5-7 cm. long. « « ...... » ' ..o.o...... 3. Cryptostegia p. 181

1. Pollen waxy; corolla never funnelform, usually smaller ..•••»» 2

2(1). Stems not twining, commonly erect; corona consisting of 5 hoods,

these appendaged within by a hornlike crest. 1. Asclepias p. 180

2. Stems twining or scandent; corona various, but not hoodlike and

without internal appendages. . .o.„ ... .o .»...«<► 3

3(2). Pollinia strictly pendulous, uniformly fertile to the attachment

of the translator...... 4

3 o Pollinia strictly erect or horizontal, not pendulous, sterile near

attachment of translator or, in Marsdenia, uniformly fertile « 7

4(3). Corona appearing double, consisting of an outer ring adnate to

corolla and 5 turgid vesicles attached to stamen column within;

corolla broadly rotate ...... 8. Sarcostemma p. 182

4. Corona not appearing double, adnate to corolla; corolla campanulate-

rotate ...... o...... o 5

5(4). Leaves long petiolate, ovate-cordate; corolla about 8 mm. long

or longer...... » « . . .6. Mellichampia p . 182

5. Leaves short petiolate or subsessile; linear or narrowly lanceolate,

not cordate; corolla much smaller. . „ ...... 6

6(5). Corolla lobes slightly imbricate in bud; stigma long-beaked

...... 2. Basistelma p 181

6 . Corolla lobes valvate in bud; stigma long-beaked «

...... o ...... 7. Metastelma p. 182 180

7(3). Pollinia horizontal or nearly so, a sterile hyaline portion

near attachment to translators...... 5. Mate lea p. 181

7. Pollinia strictly erect from attachment of translator, uniformly

fertile„ ...... 4. Marsdenia p. 181

1 o Asclepias (173)

1. Hoods spatulate, with a conspicuous solid stipe and only the

margins free to the base, the adnate horn merging with the

basal stipe. . ® Asclepias subulata

1 o Hoods cucullate, the base conduplicate but wholly laminate, the

adnate horn evident to the column or nearly so ...... 2

2(1). Anther head about as long as broad; column cylindric, not ob-

conic; horns usually gradually tapered and arching over the

anther head...... ® ...... 0 ... » 3

2. Anther head about 3/4 as long as broad, or somewhat shorter; column

obconic; horns usually abruptly beaked and sharply inflexed

over the anther head, sometimes absent . 6

3(2). Hoods strongly conduplicate, sharply keeled dorsally, with very

broadly incised margined auricles; follicles erect on deflexed

pedicels ...... Asclepias glaucescens

3 o Hoods broadly rounded, without sharply incised marginal auricles;

follicles erect on erect pedicels (pendulous or subpendulous

in A. leptotus) ...... o.,. e *4

4(3). Translator arms ligular, narrower than the gland. . . . * . . . .

...... Asclepias mexicana

4. Translator arms broadly triangular, larger than the gland. . . . . 5 181

5(4). Plants suffruticpse; leaves caducous, filiform; flowers

relatively small, greenish-white; horns adnate to about midway j - of the hoods ...... *Asclepias leptopus

5. Plants herbaceous; leaves persistent, linear to linear-lanceolate;

flowers moderately large, bright red to pinkish; horns adnate

to near the tip of the hoods ...... Asclepias gentry!

6(2). Plants herbaceous; leaves opposite, broadly oblong-ovate to oval

to rather narrowly oblong-elliptic; flowers large and showy,

deep r e d ...... *Asclepias hypoleuca

6. Plants fruticose to suffruticose; leaves spirally approximate,

filiform, pinelike; flowers rather small and crowded, greenish-

white ...... Asclepias 1inaria

2. Basistelma

One species...... Basistelma angustifolium

3. Cryptostegia

One species...... Cryptostegia grandiflora

4. Marsdenia

One species...... Marsdenia edulis

5. Matelea

1. Pollinia more or less descending from the translator arms. . . . . 2

1. Pollinia essentially horizontal, occasionally arcuate, with the tips

markedly ascending ...... 3

2(1). Stigma produced into a column; corolla rotate, greeniwh-white . .

. . „ ...... *Matelea cordifolia

2. Stigma usually depressed, never produced into a column; corolla

apparently campanulate, dark purple. . . . .^Matelea tristiflora 182

3(1), Follicles sparsely covered with spinelike projections; leaf

blades lanceolate™attenuate, acute to subtruncate at base,

glabrous or nearly so * *Matelea caudata

3. Follicles smooth, without spinelike processes or projections; leaves -

oblong”triangular-ovate, cordate at base, pubescent......

...• o • *Matelea pilosa

/ 6. Mellichampia

One species. . . . * ...... Mellichampia ligulata

7. Metastelma

1 o Flowers on pedicels 3-4 mm. long; appendages of anthers linear-

lanceolate to linear-filiform, as much as twice as long as

stamen columne e » . » » . . » . Metastelma barbigerum

1« Flowers on pedicels 1»5 m m e long or less; appendages of anthers

broadly ovate, slightly exceeding the stamen column......

. . o ...... o ... . Metastelma minutiflorum

8o Sarcostemma (50)

.1. Inflorescence corymbiform, obviously compound, the peduncle not

equalling the subadjacent internode in thickness; leaves usually

densely white tomentose beneath» • . . . . ^Sarcostemma pannosum

1. Inflorescence umbelliform, the pedicels all inserted at nearly the

same point; leaves never densely white tomentose beneath . . . 2

2(1). Peduncle equalling or exceeding the subjacent internode in

thickness, frequently bearing two catenulate cymes; leaves

elliptic to oval; flowers pale greenish yellow to white

...... ^Sarcostemma clausum 183

2 o Peduncle not equalling the subjacent internode in thickness, usually

bearing but one cyme; leaves narrowly lanceolate; flowers purple .

or pink, or the corolla lobes with a median purple streak® « P- .

...... -fSarcostemma cynanchoides

88. COMVOLVULACEAEo Morning-glory Family

1 o Plants parasitic, devoid of chlorophyll; flowers minute, usually 6

mm. long or less; leaves reduced to minute scales® ......

o o o ® o . . . . o o . . * ...... e . . .1o Cuscuta p .184

1 o Plants autophytic,green; flowers mostly larger and often showy;

leaves functional, ample . » « * .. . • • » • • » ® @ ® 2

2(1). Styles 2, separate to base or nearly so, each bearing 2 stigma

lobes; stigma lobes linear, terete . «, . « . 2. Evolvulus p. 184

2. Style 1; stigma lobes not as. above « . « « . . . « ® « ® ® . . . o 3

3(2). Corolla campanulate-rotate, tube very short . „ ...... ® , . »

...... 5. Jacquemontia p. 186

3. Corolla funnelform, deeply campanulate or salverform, tube evident „

" ...... 4

4(3) o Anthers spirally twisted...... 6. Operculina p. 187

4. Anthers straight, not spirally twisted « .® . '.• • • • e- ••••• 5

5(4). Corolla funnelform or broadly campanulate; stamens included . ® •

o ...... o o . o e4o Ipomoea p .184

5. Corolla salverform or tubular-salverform; stamens exserted or nearly

SO...... 0.6

6(5). Bracts small, inconspicuous, not enclosing flowers. ® ...... ®

o . . o . o o o o ...... 7. Quamoclit p . 187 184

6. Bracts large and conspicuous, more or less enclosing flowers » e » «

...... 3. Exogonlum p. 184

1 o Cuscuta (174)

1 e Segments of calyx and corolla obtuse „ ...... Cuscuta americana

1 o Segments of calyx and corolla acute« » « . o . » . Cuscuta umbellata

2« Evolvulus

One species. . * « ...... Evolvulus alsinoides

3. Exogonium (53)

One species. . » . . . * ...... Exogonium bracteatum

4. Ipomoea (52)

1. Plants erect, stout, perennial, shrubby or treelike...... o » 2

1 o Plants twining, creeping or prostrate, stout or slender, ® » o 5

2(1). Arborescent, erect and woody, usually over 5 m. high...... 3

2. Shrubby, usually up to 5 m. high ...... o..o,4

3(2). Plants with yellowish bark. . Ipomoea arborescens var. pachylutea

3. Plants with white-gray bark. . . . Ipomoea arborescens var. glabrata

4(2) . Leaf blades pinnately divided .do...... Ipomoea incisa

4. Leaf blades linear ...... Ipomoea chilopsidis

5(1). Sepals herbaceous...... 6

5. Sepals coriaceous, membranaceous or sub-herbaceous ...... 11

6(5). Outer sepals becoming different from the inner ones ...... 7

6. Outer sepals not becoming different, usually much like the inner

O n e S e e e . • e e ;.-e e e o e o . • • ®. • e « « o * . * • . 8

7(6). Sepals merely acute, not attenuate...... Ipomoea la eta

7. Sepals with long attenuate t i p s ...... Ipomoea heterophylla 185

8(6). Sepals acute • . . » , . . o . . * . . * ...... » 9

8o Sepals attenuate . % ...... 10 .

9(8)c Leaf blades usually entire; corolla 5-7 cm. long.Ipomoea purpurea

9. Leaf blades usually 3-lobed; corolla 2.5-4 cm. long» 6 «,

. o. . Ipomoea hirsutula

10(8) . Flowers yellowish to white ...... Ipomoea lactescens .

10. Flowers bluish to purple...... Ipomoea nil

11(5). Stems prostrate or creeping, sometimes erect, not twining. . .12

11. Stems trailing or twining, at least the tips twining...... 13

12(11). Peduncles short, 2 cm. long or less; leaf blades deltoid-

reniform to triangular-ovate, angled or toothed; corolla deep

rose-purple, 3-4 cm. long...... Ipomoea eximia

12. Peduncles large, 4-6 cm. long, usually exceeding the leaves; leaf

blades ovate, entire; corolla white, 6-7 cm. long. . .

o .... o ...... o - . Ipomoea hartwegii

13(11). Seeds with a dorsal or marginal coma longer than the seeds, or

completely covered with long hairs; peduncles filiform, fre­

quently twisted and tendril-like; sepals acute, equal; corolla

violet ...... o ... o .... . Ipomoea pulchella

13. Seeds glabrous or pubescent, at least without a conspicuous coma014

14(13). Leaf blades pedafely lobed nearly or quite to the petiole;

stems slender...... * ...... 15

14. Leaf blades entire, toothed or 3- to 5-lobed...... 19

15(14). Annual or perennial without tuber-like roots...... 16

15. Perennials from tuberous roots...... 18 186

16(15)o Stems ascending5 slender and weak; leaves pedately 5-9 divided;

corolla rose-purpleo ...... Ipomoea costellata

16. Stems trailing or twining .' . . . , ...... 17

17(16). Sepals attenuate-acuminate...... Ipomoea leptotoma

17. Sepals lanceolate, acute. . . . . * ...... Ipomoeapedatisecta

18(15). Corolla white, 8-10 cm. long...... Ipomoea laptosiphon

18. Corolla purple, 2-2.5 cm. long. . „ ...... Ipomoea muricata

19(14)# Sepals small, 3-3.5 mm. long; corolla 4-5 mm. long, yellow. . .

. . . . o . . o . . . o .... Ipomoea minutiflora

19. Sepals and petalslarge, usually over 5 mm. long, never yellow. . .

. .20

20(19). Sepals very unequal ...... Ipomoea gracilis

20. Sepals equal or nearly so ...... o ...... 21

21(20). Sepals cuspidate pointed or acuminate ...... 22

21. Sepals aristately awned ...... 23

22(21). Annual plants; sepals ciliate or sparsely ciliate; corolla 1.5-

2 cm. l o n g ...... Ipomoea triloba

22. Perennial plants; sepals glabrous; corolla 4-5 cm. long ......

...... o ...... Ipomoea gracilis

23(21). Stems usually armed with limber prickles; corolla less than 5

cm. long ...... o ...... Ipomoea cardiophylla

23. Stems usually unarmed; corolla mostly 8-10 cm. l o n g ...... 24

24(23). Leaf blades entire; peduncle 4-6 cm. long .Ipomoea pedicellaris

24. Leaf blades pedately lobed; peduncle 8-.3 mm. long. Ipomoea gentry!

5. Jacquemontia

1. Sepals glabrous. ^ . Jacquemontia oaxacana 187

1 e Sepals variously pubescent . „ . „ ...... 2

2(1)o Stems and inflorescence glandular-pilose. . . Jacquemontia azurea

2. Stems and inflorescence pubescent, but not glandular ••/••• 0 3

3(2). Plants annual, herbaceous*; corolla .7-8 mm. long; sepals all

alike ...... Jacquemontia palmeri

3 e Plants perennial, woody at base; corolla 15-25 mm. long; sepals un­

equal o . * ...... Jacquemontia pringlei

6. Operculina (51)

1 o Leaves simple» ., . . . . . « * * « « . * . . .Operculina alatipes

1. Leaves digitately compound .Operculina palmeri

7« Quamoclit

1. Leaves deeply divided into 8-10 pairs of linear to subfiliform

divisions; sepals obtuse or rounded at apex, sometimes an infra­

terminal mucronulation is present; capsules broadly ovoid,

about 5-6 mm. in diameter. . Quamoclit pinnata

1. Leaves entire or lobed; sepals conspicuously acuminate; capsules

subglobose, about 7-8 mm. in diameter...... 2

2(1). Leaves entire, cordate or subsagattate. . . . .Quamoclit coccinea

2. Leaves deeply 3-lobed, or sometimes 5-lobed......

„ ...... Quamoclit coccinea var. hederifolia

89. POLEMONIACEAB. Phlox Family

1. Actinomorphic corolla (lacking a definite expanded throat) .....

...... 2. Ipomopsis p. 188

1. Zygomorphic corolla...... 2 . * 188

2(1). Calyx foliaceous; leaves lyrate-lobate or pinnately lobed . . . .

2. Calyx membranaceous between costae; leaves dentate or serrate. . . »

1. Bonplahdia

One species......

2. Ipomopsis (37)

One species ......

3. Loeselia

1. Inflorescence bracts ovate to reniform ...... 2

1. Inflorescence bracts linear or lanceolate...... 3

2(1) Leaves mostly cordate-clasping; corolla white or purplish, about

15 mm. long......

2. Leaves not cordate-clasping; corolla pale yellow, about 10 mm. long.

» " ...... oo.oc.

3(1) Flowers several, usually in dense, long pedunculate head-like

clusters ......

3. Flowers solitary or geminate, short-pedicellate or almost sessile. .

...... Loeselia glandulosa subsp = ramosissima

90. HYDROPHYLLACEAEe Waterleaf Family

1 o Aquatic or marsh herb; ovary bilocular ...... 1. Hydrolea p. 189

1. Terrestrial herb; ovary unilocular ...... 2

2(1). Stamens inserted at different levels on the corolla tube; leaves

entire; placentation usually axial; flowers not in scorpioid

cymes...... 2. Nama p. 189 189

2 e Stamens inserted at the same level; leaves not entire; placentation

usually parietal; flowers in scorpioid., cymes .3. Phacelia p o 189

1, Hydrolea

One species o ...... Hydrolea spinosa

2. Nama (49)

1. Petioles decurrent on stem, the stems thus winged; leaves variable,

from rotund or broadly ovate to spatulate or broadly ovate-

spatulate, 0.5-3.5 cm. broad; pedicels as much as 1.5 (5). cm.

long ...... Nama jamaiense

1. Petioles not decurrent on stem, the stems not winged; leaves

variable, from linear to oblanceolate, 0.1-0.8 cm. broad;

pedicels up to 5 mm. long...... 2

2(1). A strigose-hirsute to hispid herb; leaves linear-oblanceolate;

filament bases scarcely dilated...... Nama hispidum

2. A short-villous-hirsute herb; leaves obovate-spatulate; filament

bases widened considerably ...... Nama coulteri

3. Phacelia (157)

One species...... «o . , . Phacelia congesta

91. BORAGINACEAEo Borage Family

1. Style terminal on ovary, not inserted between nutlets...... 2

1. Style borne on the gynobase and arising between nutlets...... 4

2(1). Style twice bifid, the four branches each bearing a stigma. . . .

...... o . . . . 1. Cordia p . 190

2. Style entire or once b i f i d ...... 3 190

3(2) o Fruit drupaceous; shrub or scandent perennial vines . . . ,

. . o • o . o o „ e . o o.» e e . . . . .5. Tournefortia p. 192

3. Fruit dry5 breaking into 2-4 nutlets; herbaceous plants ......

.3 • Heliotropium p. 190

4(1). Nutlets attached above the base along a usually open and general­

ly basally forked ventral groove or slit, or by a triangularj

opening in the pericarp...... 2. Cryptantha p. 190

4. Nutlets lacking a distinct ventral groove or opening in the pericarp

with this usually replaced by an elevated ventral keel „ . . * .

...... 4. Lithospermum p* 191 .

i 1 o Cordia

One species o ...... Cordia sonorae

2. Cryptantha (55)

1 o Nutlets strongly bent above the base, glossy, the margins knifelike;

gynobase narrowly pyramidal...... Cryptantha pus ilia

1. Nutlets straight, densely tuberculate, the margins rounded or

slightly angled; gynobase subulate ......

...... Cryptantha greggii var. cryptochaeta

3. Heliotropium

1 o Plants entirely glabrous and glaucous, very succulent......

...... Heliotropium curassavicum

1. Plants evidently hairy, not glaucous nor succulent ...... 2

2(1). Spikes naked; lobes of the calyx distinctly shorter than the

mature nutlets ...... 3 191

2. Spikes more or less bracteate, although not uniformly so; lobes of

the calyx equalling or considerably surpassing nutlets at

maturity ...... * ...... * * 5

3(2). Nutlest scurfy with small, white, vesicle-like cells; stigmas

sessile or essentially so...... Heliotropium angiospermum

3. Nutlets pubescent by hairs, not scurfy; stigmas on evident styles„ 4

4(3). Leaves broadly ovate, 2-7 cm. broad; corolla 5-6 mm. long; plants

erect or ascending...... Heliotropium macrostachyurn

4. Leaves oblanceolate-elliptic, 2-10 mm. broad; corolla 1.5-2 mm.

long; plants often procumbent .^Heliotropium procumbens

5(2). Lateral veins obvious, distinctly impressed above; spikes

uniformly braeteate, each bract 1-2 mm. long; stems with re­

flexed pubescence...... ^Heliotropium greenmanii

5. Lateral veins obscure or lacking, not impressed; spikes irregularly

leafy-bracteate, bracts 1-6 mm. long; stems with ascending

appressed pubescence ...... 6

6(5). Leaves linear; plants perennial; corolla 4-5 mm. long ......

...... Heliotropium limbatum

6. Leaves broadly elliptic to oblanceolate; plants annual; corolla 1-

1.5 mm. long ...... ^Heliotropium fruticosum

4. Lithospermum (54)

1. Middle cauline leaves veinless, usually rounded or obtuse, commonly

broadest above the middle, the two surfaces weakly contrasted,

both more or less sparsely strigose and the lower somewhat

glacous as well; basal leaves in a rosette; corolla yellow . . .

• ...... « » Lithospermum lasiosiphon 192 ,

1. Middle cauline leaves evidently veined, acute, broadest at or below

the middle, the two surfaces strongly contrasted, the upper

green and glabrous, the lower canescent and densely strigose

or tomemtose; basal leaves not persistent at anthesis; corolla

white o ...... Lithospermum discolor

5. Tournefortia

1. Erect, rather slenderly branched shrub; corolla white, the lobes

rounded or obtuse...... Tournefortia hartwegiana

1. Suberect to scandent shrub; corolla greenish yellow, the lobes

l i n e a r ...... Tournefortia volubilis

92. VERBENACEAEo Verbena Family

1. Leaves palmately compound« ..5. Vitex p. 195

1. Leaves simple . 2

2(1). Fruit composed of four 1-seeded nutlets or cocci......

...... 4. Verbena p. 194

2. Fruit composed on only 2 pyrenes (or by abortion 1)...... 3

3(2). Pyrenes 2-celled and 2»seeded (or by abortion 1-celled and 1-

seeded)...... 3. Priva p. 194

3. Pyrenes 1-celled and 1-seeded...... 4

4(3). Calyx rim truncate or shallowly toothed; corolla 4- or 5-lobed;

fruit usually with a fleshy exocarp...... 1. Lantana p. 193

4. Calyx rim 2- or 4-cleft or conspicuously toothed; corolla.5-lobed;

fruit with a thin dry exocarp...... 2. Lippia p. 193 193 .

1. Lantana

1 o Bracts narrow, lanceolate or oblong, usually pronouncedly imbricate; '

stems usually aculeolate; corolla tube 7-10 mm. long ..... 2

1. Bracts broadly ovate, pronouncedly imbricate; stems never aculeo­

late; corolla tube 5-6 mm. long. . ® . . . 3

2(1). Leaves relatively small, mostly 3-5 cm. long and 2-4 cm. wide,

very coarsely toothed...... Lantana horrida

2.o Leaves relatively large, mostly 5-11 cm., long and 2.5-7 cm. wide,

regularly and more abundantly toothed, the teeth appressed . . .

...... Lantana glandulosissima

3(1). Leaf blades commonly very densely canescent-tomentose or veluti-

nous beneath; peduncles 1-7.5 cm. long; bractlets mostly

subacute or obtuse at apex, densely appressed-pubescent or

velutinous; upper leaf surface more or less bullate, marginal

teeth rounded...... Lantana velutina

3. Leaf blades usually appressed strigose beneath; peduncles 4-14 cm.

long; bractlets mostly acuminate at apex, appressed strigose;

upper leaf surface not bullate, marginal teeth narrow......

...... Lantana achyranthifolia

2. Lippia

1. Bracts of inflorescence conspicuously 4-ranked; leaf blades uni­

formly s m a l l ...... * . . . . . 2

1. Bracts of inflorescence not conspicuously 4-ranked, usually ir­

regularly imbricate; leaf blades variable in size...... 3

2(1). Heads short-pedunculate or almost sessile; leaves short, mostly -

less than 2 cm. long ...... Lippia palmeri 194

2. Heads usually long-pedunculate; leaves longer9 mostly more than 2

cm. long o . . o . o . c . . o ...... Lippla berlandieri

3(1). Flower heads small, about 4-8 mm. in diameter at anthesis ....

...... o * ...... Lippia pringlei *

3 o Flower heads large, about 8-15 mm. in diameter at anthesis......

...... Lippia gentryi •

3. Priva (68)

1. Fruiting calyx broadly ovate, not enclosing the fruit; dorsal, sur-

.face of cocci distinctly echinate...... Priva lappulacea

1. Fruiting calyx globose, enclosing the fruit; dorsal surface of cocci

usually furrowed, not echinate...... Priva aspera

4o Verbena (110)

1 o Spikes mostly slender and elongate after anthesis; calyx seldom

more than twice as long as the fruit, not contorted above it;

corolla often small, not showy; anthers unappendaged; sterile

style-lobe usually not surpassing the stigmatic surface: Section

, Verbenaca...... Verbena menthaefolia

1. Spikes mostly broad and dense; calyx usually more than twice as long

as the fruit and constricted or contorted above it; corolla

relatively large and showy; connective of the upper anthers

chiefly appendaged; sterily style-lobe distinctly surpassing the

stigma tic lobe: Section Glandularia...... 2

2(1). Nutlets suggesting a tendency toward a beak (a slight protrusion

horizontal to the axis of the schizocarp); commissural face

practically reaching the tip of the nutlet . . Verbena delticola 195

2. Nutlets without a beak; commissural face not reaching the tip of

the nutlet ...... 3

3(2). Corolla tube only slightly longer than the calyx. .Verbena pumila

3c Corolla tube protruding well beyond the c a l y x . * 4

4(3). Corolla tube approximately twice as long as the calyx ......

o . . » ...... Verbena elegans var. asperata

4. Corolla tube one-third to one-half longer than the calyx ...... 5

5(4). Floral bracts equalling or exceeding the calyx; calyx hispid-

hirsute, not glandular ...... Verbena bipinnatifida

5. Floral bracts shorter than the calyx; calyx for the most part some­

what glandular ...... Verbena ciliata

5. Vitex

1. Leaflets mostly 3; corolla densely pubescent outside . .Vitex mollis

1 o Leaflets mostly 5; corolla lightly puberulent outside« ......

o ...... Vitex pyramidsta

93. LABIATAEo Mint Family

1. Ovary of 4 united nutlets; styles not basal; nutlets laterally

attached ...... » 2

1. Ovary of 4 distinct or nearly distinct nutlets; styles basal; nut­

lets basally attached...... 3

2(1). Upper lip of corolla much shorter than lower; stamens equalling

or moderately exserted ...... 11. Teucrium p. 200

2. Upper lip of corolla about same length as lower; stamens usually

much exserted...... 12. Trichosterna p. 200

3(1). Calyx 2-lipped, the lips entire ...... 9. Scutellaria p. 199 196

3 o Calyx 5-toothed, or if 2-lipped, the lips not entire 4

4(3). Corolla regular or nearly so; fertile stamens 4; foliage strongly.

aromatic ...... ^...... 5. Mentha p. 197

4. Corolla strongly 2-lipped. . ■ . . * ...... • „ . . . 5

5(4). Stamens declined and enveloped by the lower lip of corolla. . . 6

5. Stamens ascending, not declined or enveloped by the lower lip of

corolla ...... o . o . 7

6(5). Calyx teeth erect, not spreading; corolla 2-lipped, lower lip

often saccate-drooping ...... 4. Hyptis p.197

6. Calyx teeth stellately spreading in fruit; corolla weakly bilabiate,

lower lip not saccate-drooping ...... 2. Asterohyptis p. 197

7(5). Upper lip of corolla plane, usually erect; fertile stamens 2. „ .

...... 3. Hedeoma p . 197

7. Upper lip of corolla more or less galeate, distinctly concave« . . 8

8(7). Fertile stamens 2 ...... 9

8. Fertile stamens 4 ...... o. o ...... 10

9(8). Anther connectives elongated, articulated with filaments; pollen

sacs distinctly separated, or lower one wanting; calyx 2-

l i p p e d ...... 8. Salvia p. 198

9. Anther connectives not elongated; pollen sacs approximate; calyx

equally 5-cleft...... 6. Monarda p. 198

10(8). Upper pair of stamens longer than lower pair ......

...... 1. Agastache p. 197

10. Upper pair of stamens shorter than or equal to lower pair . . . .11

11(10). Calyx 2-lipped, closed in fruit ...... 7. Prunella p & 198

11. Calyx 5-toothed, not closed in fruit...... 10. Stachys p. 200 197 1. Agastache (74)

1. Corolla tube 20-30 mm. long. , „ » ...... ^Agastache barberi

1 o Corolla tube less than 20 mm. long „ . . . „......

• .-HAgastache pallidiflora subsp. mearnsi

2 o Asterohyptis (24)

1 o Glomerules 8-12 mm. in diameter at maturity; calyx teeth 2-4 mm.

long at maturity; calyx tube glabrous within; leaves ovate to

lance-ovate...... ^Asterohyptis stellulata

1 o Glomerules 5-7 mm. in diameter at maturity; calyx teeth Qo5-0o7 mm.

long at maturity; calyx tube bearing ring of silvery hairs in .

thread; leaves oblong-lanceolate . . . . .*Asterohyptis seemanii

3« Hedeoma

1. Calyx strongly zygomorphic, 2 teeth longer than the other 35 the

throat not densely bearded on upper part; flowers few, terminal

and lateral...... Hedeoma .patens.

1. Calyx regular, the 5 teeth usually equal or nearly so, the throat

densely bearded on upper part; flowers numerous at apex of

stems only ...... Hedeoma floribunda

4. Hyptls

1, Plant cinerous, floccose-tomentose with fine, dendritically branched

hairs...... Hyptis albida

1. Plants not as above, or if so, the hairs not branched...... 2

2(1). Flowers subtended by ovate or elliptic bracts . .Hyptis mutabilis

2. Flowers subtended by linear bracts ...... 3

3(2). Corolla tube 4-6 mm. long; mature calyx tube 5-7 mm. long . . .

...... Hyptis suaveolens 198

3 o Corolla tube 3.5-4 mm. long; mature calyx tube less than 5 mm. long„

o.oooo ...... Hyptis septentrionalis

5. Mentha (147)

One specieso ...... ^Mentha aryensis. var. villbsa

6. Monarda (135)

One species...... ^Monarda citriodora subsp. austromontana

7. Prunella

One species...... * . . * ...... , . * .Prunella vulgaris

8 o Salvia

1 o Corolla 2 cm. long or l o n g e r...... 2

1. Corolla less than 2 cm. long ...... o o o .. 4

2(1). Flowers bright purple ...... Salvia mexicana

2. Flowers bright red to reddish. •.••••3

3(2). Leaves smalls the blades mostly 1-2 cm. long. . . . . ' . . . . .

...... Salvia microphylla var. wislizenii

3 o Leaves much larger, the blades mostly 5-15 cm. long. . • . .

...o.-ooo.o...... Salvia elegans var. sonorensis

4(1). Shrubby, distinctly woody, at least at base ...... 5

4. Plants herbaceous, annual or perennial, only faintly woody at base .

o © o o e o e

5(4). Upper lip of clayx 7-9 veined, often obscure; lower surface of

leaves pubescent with minute stellate hairs. . .Salvia goldmanni

5. Upper lip of calyx 5-7 nerved, conspicuous; lower surface of leaves

pubescent with stellate and simple hairs . . .Salvia melissodora

6(4). Herbaceous perennial...... * ...... 7

6. Herbaceous annual; ...... 9 199

7(6). Leaf blades elliptic-oblong, the margins sub-entire to obscurely

serrate...... Salvia muscarioides

7. Leaf blades rhomboida1-ovate or narrowly deltoid to deltoid-ovate,

the margins crenate-serrate to serrate 8

8(7) . Corolla tube 6-6.5 mm. long; calyx 5.5-7 mm. long, sparsely

hirtelous to nearly glabrous; leaf blades rhomboid-ovate ....

...... Salvia seemannii

8. Corolla tube 4-5.5 mm. long; calyx about 4 mm. long, densely hispid;

leaf blades narrowly deltoid to deltoid ovate. .Salvia alamosana

9(6). Flowers in dense globose verticils...... Salvia ga1insogifo1ia

9 o Flowers not as a b o v e ...... 10

10(9). Stamens exserted beyond upper corolla lip, at least the thecas;

nutlets 1.4-1.6 mm. long ...... Salvia tiliaefolia

IQ. Stamens included within obviously galeate upper lip of corolla;

nutlets often 2 mm. long or more ...... 11

11(10) . Inflorescence., very dense and continuous, spike-like , . . . . .

...... Salvia hispanica

11. Inflorescence much interrupted, the verticils of flowers separated.

...... , ...... 12

12(11). Corolla tube about 3 mm. long; leaf blades deltoid-ovate. . . .

...... Salvia setosa

12. Corolla tube about 5.5 mm. long; leaf blades rhomboid » ......

. , o ...... Salvia monantha

9. Scutellaria (26)

One species...... Scutellaria horfidula 200

10 o Stachys (25)

1. Corolla tube 2.5-4 mm* long...... Stachys agraria

1. Corolla tube 9-21 mm® l o n g ...... 2

2(1). Corolla purplish or pink to pink-lavender, the tube 9-15 mm.

long, hirtelous within but scarcely annulate; upper lip of

corolla 3-4 mm. t a l l ...... Stachys bigelovii

2. Corolla bright red, the tube 18-21 mm. long, annulate near the base,

upper lip of corolla 6-8 mm. tall...... Stachys coccinea

11. Teucrium (78)

One species...... *Teucrium cubense subsp. depressum

12o Trichosterna (72)

One species...... Trichostema arizonicum

94. SOLANACEAE6 Nightshade Family

1. Seeds not strongly compressed; embryo straight or nearly so. . . . 2

1. Seeds moderately to strongly compressed laterally; embryo strongly

curved ...... o ...... 3

2(1). Fruit capsular; narcotic poisonous, heavy-scented plants. ....

6. Nicotiana p. 202 \ 2. Fruit baccate; plants neither narcotic poisonous nor heavy-scented .

...... 2. Oestrum p . 202

3(1). Plants shrubby; branches spinose...... 4

3. Plants herbaceous; branches usually not spinose...... 5

4(3). Corolla rotate; anthers opening by terminal poresor slits;

berry black, yellow or sometimes greenish, but scarcely bony . .

...... 9. Solanum p . 204 201

4» Corolla never rotate; anthers completely dehiscent longitudinally;

berry reddish or fruit greenish and bony . . , .4. Lyeium p. 202 .

5.(3-) . Calyx accrescent in fruit to entirely investing the berry • . . •

• . . .7. Physalis p. 203

5. Calyx usually not noticeably accrescent in fruit, or if so, never

enveloping berry ...... 6

6(5). Fruit a capsule, this prickle-armed; calyx circumscissile at

base; corolla funnelform, more than 10 cm. long.3. Datura p. 202

6. Fruit a berry, juicy, fleshy or leathery; calyx not circumscissile

at base; corolla rotate to broadly campanulate, much smaller

than above ...... 7

7(6) . Stems sharply. 4-angled; calyx saucer-shaped and markedly reticu­

late veined in fruit; corolla greenish .... 8. Saracha p. 204

7. Stems not markedly 4-angled, calyx not saucer-shaped, nor conspic­

uously veined in fruit; corolla never greenish ...... 8 . i . 8(7). Anthers connate into a pointed cone, terminated by a sterile tip,

the cells dehiscent longitudinally down the inner surface. . . .

o ...... 5. Lycopersicon p. 202

8. Anthers not as above ...... 9

9(8). Anthers bluish, scarcely longer than the filaments, the cells

dehiscent longitudinally...... 1. Capsicum p. 201

9. Anthers yellow, much longer than the filaments, the cells opening

by terminal pores or slits ...... 9. Solanum p. 204

1. Capsicum

1. Leaves small, usually entire; flowers solitary . . Capsicum baccatum 202

1. Leaves larger5 commonly coarsely repand-dentate; flowers grouped * -

...... Capsicum straminiifo 1 ium

2. Cestrum

One species. . . « « » ...... Cestrum lanatum

3. Datura (30)

One species a „ o .... .o ...... ^Datura innoxia

4. Lycium (48)

1. Leaf blades 3 mm. broad or more3 densely and finely pubescent,

somewhat glandular viscid; calyx densely pubescent . . . . * * .

...... Lycium exsertum

1. Leaf blades rarely over 3 mm. broad, glabrous or slightly scurfy,

rarely minutely puberulent; calyx glabrous or nearly so... e 2

2(1). Style exserted 4-7 mm. . . . Lycium berlandieri var. longistylum

2 e Style exserted less than 4 mm...... Lycium andersonii

5. Lycopersicon (91)

One species ...... ^Lycopersicon esculentum ivar. cerasiforme

6. Nicotiana

lo Shrub or small tree; leaves glaucous, glabrous; flowers greenish-

yellow ...... o . .Nicotiana glauca

1. Herbaceous plant; leaves green, more or less viscid-pubescent, not

glaucous; flowers not y e l l o w ...... o .. o 0 ...... 2

2(1). Corolla 18-22 mm. long, greenish-white in color; capsule 8-10

mm. long ...... Nicotiana trigonophylla

2. Corolla larger, usually more than 23 mm., pale cream color, often

tinged with pink or red; capsule 15-20 mm. long...... «

...... Nicotiana tabacum 203

7» Physalls (158)

1. Fruiting calyx 5-angled; leaf blades more or less translucent when

dry; some of the hairs with brownish glands.Physalis leptophylla lo Fruiting calyx 10-ribbed, subequally 10-angled, or teretish . , 2

2(1). Indument of stellate hairs, rarely partly dendritic ......

. o o o o .» o e e . *Physalis viscosa subsp. mollis -

2. Indument various, but not stellate, sometimes dendritic or partly

so s sometimes none . • . . . • * ...... * .. . * 3

3(2). Flowering pedicels usually (10-) 15-40 mm. long, several times

the length of the flowering calyx. » . » 4

3. Flowering pedicels shorter than the calyx to 2-3 times its length,

usually 3-10 mm. long...... 5

4(2). Corolla remaining yellow when dried; leaves thick, often entire;

flowering calyces usually 4-6 mm. long on pedicels from little

longer than to 6-7 times their length......

...... *Physalis crassifolia var. crassifolia

4o Corolla often drying with a blue tinge; leaves thin, often toothed,

flowering calyces usually 3-4 mm. long on pedicels 5-10 times

their length ...... *Physalis crassifolia var. versicolor

5(3). Fruiting pedicels about 1 cm. long...... Physalis caudella

5. Fruiting pedicels 3-8 mm. long 6

6(5). Young parts with a few short hairs, chiefly sepals and pedicels .

^Physalis philadelphica var. philadelphica forma philadefphica

6. Young parts (sepals and pedicels) with long jointed hairs in varying

abundance ...... ,

. . o . '(physalis philadelphica var. philadelphica forma pilosa 204

8. Saracha (88)

One species...... » . « . » . +Saracha procumbens '

9. Solanum

1. Plants prickly ...... * . 2

1. Plants never p r i c k l y...... 5

2(1). Fruit densely hirsute . .Solanum tequilense

2. Fruit glabrous or nearly so. .... ® ...... 3

3(2). Plants annual herbs; leaves pinnatifid; seeds transversely ridged

across rounded back, dull black. . . o ...... Solanum grayi

3. Plants shrubby, or perennial more or less suffrutescent herb;

leaves not pinnatifid; seeds not transversely ridged dorsally,

usually yellowish or brownish...... 4

4(3). Flowers purple; stamens unequal, longer anthers 12-16 mm. long. .

...... Solanum amazonium

4. Flowers white; stamens subequal, longer anthers 8-10 mm. long. . . .

. . . e o o ...... Solanum madrense

5(1). Plants annual herbs; flowers solitary or geminate, on slender,

strongly deflexed pedicels, without an evident peduncle; herbage

and calyx pubescent with stiff, more or less spreading hairs . .

* ...... Solanum deflexum

5. Plants shrubby, or perennial more or less suffrutescent herbs;

flowers on pedicels not strongly deflexed, the peduncles usually

evident; herbage and calyx glabrous, or pubescent with stellate

hairs, or if unbranched, the hairs neither stiff nor spreading .

...... 6 205

6(5). Plants entirely glabrous; pedicels geminate .Solanum geminiflorum

6. Plants pubescent; pedicels not geminate. . . . « e ...... 7

7(6). Mature leaves pubescent with stellate hairs ...... 8

7. Mature leaves pubescent with simple hairs...... e „ 9

8(7). Young branches with coarse, conspicuously stipitate, branched

hairs o ...... Solanum umbellatum

8. Young branches with fine stellate hairs, these sessile or nearly so.

...... d . . . o ...... o . .Solanum verbascifolium

9(7). Ripe berries black...... Solanum nigrum

9. Berries greenish when ripe, or yellowish or reddish. Solanum gracile

95. SCROPHULARIACEAE 6 Figwort Family

1. Corolla with posterior lobes external, overlapping in the bud. . * 2

1. Corolla with anterior lobes external, overlapping in the bud . . .10

2(1). Capsule densely packed with tortuous long hairs ......

...... 13. Russelia p. 210

2. Capsule not densely packed with hairs...... 3

3(2). Stigmas distinct, two-lipped, flattened; seeds often reticulated

or cross ribbed, wingless; leaves opposite or whorled...... 4

3. Stigmas united, punctiform or capitate; seeds smooth, tuberculate,

ridged or winged ...... 8

4(3). Leaves pinnatifid; capsule narrowly lanceolate, acuminate; seeds

spirally ridged...... 14. Schistophragma p. 210

4. Leaves not pinnatifid; capsule broader, usually ovate; seeds not

spirally ridged...... 5 5(4) o Cells of the anthers divergent; pedicels ebracteolate . „ . . „ „

e . . . o o , ...... » o . o e . . . . 9 e Mimulus p » 209 .

5. Cells of the anthers parallel or nearly so; pedicels usually .

bracteolate. <, o ...... o, ... 6 '

6(5). Anther cells stiped (each borne on a short arm of the connective)

sepals uniform or essentially so 16. Stemodia p. 210 .

6. Anther cells not stiped. . » ...... 0 ...... 7

7(6). Pedicels bibracteolate at apex; sepals nearly equal in width;

fertile stamens two; corolla whitish . . . . .6. Gratiola p. 208

7. Pedicels bibracteolate at base; sepals unequal, the outer much

wider than the inner; fertile stamens 4; corolla yellow. ....

...... o ...... 10. Mecardonia- p. 209

8(3). Capsule primarily septicidal (dehiscence through the partitions);

corolla not calcarate or saccate at base . .12. Penstemon p. 209

8. Capsule loculicidal (dehiscence between the partitions); corolla

saccate or calcarate at base . . . . . «... o 9

9(8). Leaves linear, entire, capsule usually asymmetric, opening by

narrow, subapical perforations or irregular chains; plants

glandular pubescent, at least in the inflorescence « ® . » » * »

...... 1. Antirrhinum p. 208

9. Leaves broadly cordate or reniform, coarsely serrate; capsule sym­

metric , opening nearly or quite its entire width; plants not

glandular pubescent...... 8. Maurandia p . 209

10(1). Upper lobes of corolla flattened or widely arched, often

spreading; anthers all distinct...... 11 207

10o Upper lobes of corolla narrowly arched forming a galea that

encloses the anthers; anthers frequently cohering. . . « . . .15

11(10). Stamens 2, the postero-lateral pair alone developed; corolla

small, less than 5 mm. long, the posterior lobes united; plant

not parasitic* . . . . * . . . . 17. Veronica p* 210

11 * Stamens 4, didynamous; corolla more than 5 mm. long, the lobes all

evident; root parasites* . * ...... * *12

12(11). Stamens with only one anther cell developed; corolla salver-

form, the tube less than 1*5 cm. long; calyx tubular, the

tube less than 1 cm. long. »,..*... * *2. Buchnera p* 208

12. Stamens with both anther cells developed; corolla campanulate or

salverform, the tube 8-15 cm. long; calyx campanulate or in-

fund ibul if orm, in the latter the tube more than 1 cm. long . .13

13(12). Corolla salverform; calyx infundibuliform; seeds linear, in

an ellipsoid capsule; pedicels bracteolate . 4. Escobedia p * 208

13. Corolla campanulate or subcampanulate; calyx campanulate; seeds

not linear, or if so, then capsule sub-globose; pedicels

ebracteolate * . * * . * . . * . .14

14(13). Anther cells glabrous, each opening 1/2 to 2/3 its length; leaf

blades pinnatifid. ...**.***.... 15. Seymeria p. 210

14. Anther cells villous, each opening throughout; leaf blades

entire ...... * ,*...*.* .5. Gerardia p. 208

15(10). Leaves opposite, not chiefly radical; anther cells normally

strongly calcarate at base, wooly. . . . .7. Lamourouxia p * 208 208

15. Leaves alternate, or the lowest opposite, often radical; anther

cells neither strongly calcarate at base nor wooly 016 ■

16(15). Anther cells equal in.size and position; seed coat not

obviously reticulate • • • • • e « . . • <,11. Pedicularis p. 209

16. Anther cells unequally placed, the upper one attached by its

middle; seed coat evidently reticulate . . .3. Castilleja p. 208

1 o Antirrhinum (92)

One species o » ...... -Antirrhinum kingii var. watsoni

2. Buchnera

One specieso 0 ...... Buchnera pusilla

3. Castilleja (22)

1. Flowers peduncled, the pedicels about 1 cm. long; inflorescence a

raceme ...... Castilleja patriotica

1. Flowers sessile; inflorescence a s p i k e ...... 2

2(1). Floral leaves narrow, the apex not or scarcely colored0 .....

. o ...... Castilleja tenuiflora

2. Floral leaves broader, the apex always colored with purple or red. .

...... o ..... V . .Castilleja lithospermoides

4. Escobedia

One species o » . » ...... Escobedia af. scabrifolia

5. Gerardia

One species...... * Gerardia peduncularis

6. Gratiola

One species...... *Gratiola brevifolla

7 o Lamourouxia (27)

One species. . .^Lamourouxia ylscpsa 209

8. Malxrandia

One species ...... Maurandla f lavif lora .

9 o Mimulus (36)

1 e Calyx teeth equal or nearly so; plants annual, viscid-villous;

corolla cylindrical to funnelform, 7-14 mm. long, yellow, the

throat usually dotted or streaked with red . Mimulus floribundus

1. Calyx teeth unequal, the posterior tooth larger than the others. • 2

2(1). Lower teeth of mature capsule folding over the lateral and upper

tooth; calyx becoming inflated at maturity; corolla yellow;

stamens included * ...... 3

2. Lower teeth of mature capsule not folding over the lateral and upper

tooth; calyx not inflated at maturity; corolla red; stamens

much exserted. . , . * ...... Mimulus verbenaceous

3(2). Corolla 8-15 mm. long, throat open; calyx teeth 3 . * . . . . * .

...... Mimulus pallens

3. Corolla 1.5-4 cm. long, the throat partly or nearly closed by the

prominent palate; calyx teeth never 3 ...... Mimulus guttatus

10. Mecardonia (108)

One species...... ^Mecardonia vandellioides

11. Pedicularis

One species...... o .. . .Pedicularis angustifolia

12. Penstemon (17, 64, 148)

1. Staminode prominently bearded with yellow hairs; corolla 15-20 mm.

long ...... Penstemon parryi

1. Staminode glabrous, or (in P. gentryi) with minute yellow-papillate

hairs; corolla more than 20 mm. long ...... 2 2(1). Leaves entire; anther sacs obviously spinose dentate along the

suture; flowers red-purple . . . .Penstemon stetiophyllus

2 e Leaves sparingly serrate with appressed teeth in the distal half to

two-thirds only5 basally entire; flowers pale-lavender; anther

sacs not as above» ...... Penstemon gentryi

13. Russelia (120)

1. Stems terete, at least the older ones...... Russelia multiflora

1. Stems angulate ...... * ...... » „ « . .2

2(1). Stems conspicuously 4-angled...... Russelia sarmentosa

2. Stems more than 4-angled3 usually 6 ...... Russelia verticillata

14. Schistophragma

One species...... Schistophragma intermedia

15. Seymeria

One s p e c i e s ...... Seymeria chihuahuana

16. Stemodia

1 o Plants perennial; larger leaves subsessile and auriculate-clasping;

upper 'flowering stems spiciform...... Stemodia durantifolia

1 o Plants annual; leaves all petidlate, not clasping; flowering stems

not spiciform...... Stemodia pusilla

17. Veronica (107)

One species...... Veronica peregrina var. xalapensis

96c BIGNONIACEAE. Bignonia Family

1. Plants scandent; branches often with aerial roots; leaves usually

trifoliolate, the terminal one usually modified into a tendril 211

1. Plants erect; aerial roots none; leaves not trifoliolate, nor with

tendrils ...... 3

2(1). Tendrils with sharp-pointed hooked tips; corolla yellow ......

...... 2. Bignonia p. 211

2. Tendril without sharp-pointed tips corolla purple ......

...... • . .1. Arrabidaea p. 211

3(1). Shrub or small tree, up to 8 m. tall; leaves pinnate......

...... 4. Tecoma. p. 211

3. Tree, 5-15 m. tall; leaves digitately compound . .3. Tabebuia p. 211

1. Arrabidaea

One species...... Arribidaea liptoralis

2. Bignonia

One species...... Bignonia unguis-cati

3. Tabebuia

1. Calyx about 6-7 mm. long, covered with fine close whitish tomentum;

corolla pink ...... Tabebuia palmer!

1. Calyx about 1 cm. long, covered with long, short-barbate fulvous or

brown hairs; corolla yellow...... Tabebuia chrysantha

4. Tecoma

One species...... Tecoma starts

97. PEDAL1ACEAE. Pedalium Family

1. Sesamum

One species...... Sesamum indicum 212

98 o MARTYNIACEAE (42) . Martynia Family

1. Calyx 5-lobed, split ventrally to the base; fertile anthers 4; horns

of fruit as long as or longer than the body......

. o ...... o o o e ...... 2. Proboscidea p. 212

1. Calyx composed of 5 free sepals; fertile anthers 2; horns of fruit

shorter than the body...... 1. Martynia p« 212

1. Martynia

One species...... Martynia annua

2. Proboscidea

1. Perennial plants, arising from a tuberous root; corolla buff or

orange or brownish yellow; fruit crested, both dorsally and

ventrally; raceme 3-7-flowered « . . . ^Proboscidea altheaefolia

1. Annual plants, arising from a tap root; corolla purplish-violet to

reddish-purple; fruit crested dorsally only; raceme 10-20-

flowered ...... ^Proboscidea ffagrans

99. OROBANCHACEAEo Broomrape Family

} 1. Orobanche (93)

One species...... Orobanche ludoviciana

100. GESNERIACEAEo Gesneria Family

1. Achimenes

One species...... Achimenes grand if lor a

101. LENTIBULAR1ACEAE.. Bladderwort Family

1. Utricularia

One species...... Utricularia gentry! 213

102. ACANTHACEAEo Acanthus Family

1. Stamens 4. . 2

1. Stamens 2» • ...... » « • • „ * . . . » . . • • 0 e 4

2(1). Anthers 1-celled; corolla strongly bilabiate, the lobes over­

lapping but not contorted in bud ...... *3. Berginia p . 215

2. Anthers 2-celled; corolla slightly bilabiate, the lobes contorted

in b u d ...... o o ..... o . , 3

3(2). Flowers axillary, solitary or few-flowered clusters; anther cells

mucronate at base...... 6. Dyschoriste p . 215

3. Flowers in loose terminal panicle; anther cells mutinous at base » .

o • .12. Ruellia p. 216

4(1). Staminodes present, well developed; corolla limb equally or sub«

equally 5-lobed; bracts small. . . . .11. Pseuderanthemum p . 216

4. Staminodes absent...... 5

5(4). Peduncles entirely covered with many lanceolate coriaceous

bracts; seeds borne on papilliform retinacula; corolla limb

blue ...... 7. Elytraria p. 216

5. Peduncles, if present, without bracts; seeds borne on hooklike

retinacula ...... o. ... 6

6(5). Flowers in dense spikes; corolla limb pale yellow, often tinged

or spotted with purple ...... 13. Tetramerium p. 216

6. Flowers variously arranged .. . . o ...... 7

7(6). Internal bracts connate from base nearly to apex on posterior

side, forming a capsule-like involucre, much larger than

externalbracts...... 8. Henrya p. 216 214

7. . Internal bracts narrow, not at all connate, commonly shorter than

external bracts» ...... o. o ...... 0 ..0 . 8 .

8(7). Stems 6-angled; flowers subtended by a pair of thin, valvelike

closely compressed, cordate bractlets, these very different from '

the foliage leaves; placenta separating from the mature capsule

valves ...... 5. Dicliptera p. 215 .

8. Stems terete or subquadrangular; flowers not so subtended; placenta

remaining attached to the capsule valves ...... 9

9(8). Anther cells inserted at the same height, or very nearly so,

parallel, contiguous, muticous . » ...... 10

9. Anther cells inserted at different heights ...... 11

10(9). Corolla lobes widely spreading, longer than the tube; flowers

small; interrupted spikes few-flowered . 4. Carlowrightia p. 215

10. Corolla lobes erect-recurved, often shorter than the tube; flowers

large; unilateral spikes with numerous flowers ......

...... o o ... o ...... 1. Anisacanthus p. 214

11(9). Anther cells not appendaged at base. . . . .9. Jacobinia p. 216

11 o Anther cells appendaged at base ...... 12

12(11). Corolla tube usually ampliate above; flowers sessile......

. . . o o . . o . . o ...... 10. Justicia p. 216

12. Corolla tube slender, not or scarcely ampliate; flowers pedicellate

...... o o ... o o o ...2. Beloperone p. 215

1. Anisacanthus (38)

1. Bracts of inflorescence foliaceous, obscuring the calyx, this 5-7

mm. long; entire surface of the plant glandular, at least in the

young stages ...... Anisacanthus abditus 215

1. Bracts of inflorescence neither foliaceous nor obscuring the calyx,

this 9-20 mm. long; glands usually confined to the inflorescence

...... Anisacanthus thurberi

2. Beloperone

One species...... Beloperone californica

3. Berginia

One species ...... Berginia virgata

4. Carlowrightia

1. Leaves linear or nearly s o ...... 2

1. Leaves lanceolate to broadly ovate . 3

2(1). Branches of inflorescence glabrous. . . . Carlowrightia pectinata

2. Branches of inflorescence puberulent . . . .Carlowrightia lindauiana

3(1). Flowers axillary or in short spikes; leaves 1.5 cm. long or less.

• ...... Carlowrightia pubens

3. Flowers chiefly in long naked spikes; leaves 3-7.5 cm. long. . . . 4

4(3). Leaves rounded or obtuse at .base; stipe longer than the body of

the capsule...... Carlowrightia glabrata

4. Leaves cordate or sub-cordate at base; stipe equalling the body of

the capsule...... Carlowrightia californica

5. Dicliptera

One species...... Dicliptera resup inata

6. Dyschoriste (69)

1. Plants glandular-pubescent; leaves ovate to oblong-ovate, 3-8 cm.

long, 1.5-3 cm. broad...... Dyschoriste hirsutissima 216

1. Plants pubescent, but not glandular; leaves lance-elliptic to

slightly obovate, 1 *5-4 cm..long, 0.5-1.6 cm. b r o a d ......

Dyschoriste pringlei

7. Elytraria

One species Elytraria squamosa

8. Henrya

One species...... Henrya ortegana

9. Jacobinia

1. Bracts equalling or longer than the calyx. . . . Jacobinia candicans

1. Bracts much shorter than the calyx ...... Jacobinia mexicana

10. Justicia

1. Herbaceous plant up to 1 m. high; flowers lavender borne in close

axillary clusters; bracts thick, narrowly obovate, up to 3 mm.

wide ...... Justicia furcata

1 o ShrubS. ooo .« ooooo . . o e e e « « e o e ® * o.ooo . 2

2(1). Calyx 4-parted, glandular-pubescent; bracts and bractlets fili­

form, about 3 mm. long; corolla white or light mauve ......

...... Justicia salviaefolia

2. Calyx 5-parted, without glandular pubescence; bracts and bractlets

linear-lanceolate or oblanceolate, more than 3 mm. long; corolla

scarlet...... Justicia mexicana

11. Pseuderanthemum

One species...... Pseuderanthemum sp.

12. Ruellia

1. Shrub; capsules sparingly glandular-puberulous . Ruellia californica

1. Herbaceous or suffrutescent plants; capsules often glabrous. . . . 2 217

2(1). Calyx 8-15 mm. long, glandular pilose; corolla purplish, 2-2.5

cm. long; capsules clavate, 8-9 mm. long . . .RueIlia albicaulis

2. Calyx 15-28 mm. long, glabrous, or if pubescent, the hairs not

glandular; corolla mauve, 3-6 cm. long; capsules cylindric, 17-

20 mm. long...... Ruellia tuberosa

13. Tetramerium

One species...... Tetramerium hispidum

103. PLANTAGINACEAE. Plantago Family

1. Plantago

One species...... Plantago argyrea

104. RUBIACEAE. Madder Family

1. Ovules more than 1 in each cell of the ovary ...... 2

1. Ovules 1 in each cell of the ovary ...... 6

2(1). Fruit baccate ...... 3

2. Fruit dry ...... 4,

3(2). Corolla lobes imbricate ...... 8. Hoffmannia p. 219

3. Corolla lobes contorted...... 11. Randia p.220

4(2). Seeds exalate ...... 9. Houstonia p. 219

4. Seeds w i n g e d ...... 5

5(4). Corolla lobes valvate ...... 2. Bouvafdia p. 218

5. Corolla lobes imbricate...... 5. Coutarea p. 219

6(1). Seeds pendulous, the radicle superior; shrubs or trees. .... 7

6. Seeds ascending, the radicle inferior; plants often herbaceous . . 8

7(6). Flowers in dense, globose heads; stamens 4, usually inserted in •

the corolla throat; fruit dry...... 3. Cephalanthus p. 218 218

7. Flowers not as above; stamens 15, usually inserted at base of

corolla tube; fruit a drupe» ...... 4. Ghiococca p„ 218 .

8(6). Stipules foliaceous, resembling the leaves. « . .7. Galium p. 219

80 Stipules setiferous. .. o ...... * . . . 9

9(8).. Fruit not separating into cocci, the whote fruit circumscissile .

...... 10o Mitracarpus p. 219

9 o Fruit separating into cocci, these not circumscissile. - ...... 10

10(9) . Cocci indehiscent...... 6. Crusea p. 219

10. Cocci, at least one of them dehiscent.. 1. Borreria p. 218

1. Borreria

1 o Plants annual; leaf blades elliptic to ovate; flowers in clusters

in all or many of the leaf axils ...... Borreria laevis

1. Plants perennial; leaf blades linear to lanceolate; flowers in dense

terminal heads ...... Borreria suaveolens

2. Bouvardia (5)

1. Leaves opposite; corolla white to greenish or yellowish-white,

glabrous outside ...... Bouvardia multiflora

1 o • Leaves all or mostly in verticils of 3 or 4; corolla commonly red,

externally pubescent with papillose white red-tipped trichomes *

...... ^Bouvardia ternifolla

3. Cephalanthus

One species. ...o.eo. Cephalanthus salicifolius

4. Ghiococca

One species...... Ghiococca petrina 5. Goutarea do Pedicels ebracteate; calyx lobes 6-10 mm. long; corolla lobes

often half as long as the tube „ . .Coutarea latiflora lo Pedicels bracteate, at least at or below the middle, the bracts

small, subulate; calyx lobes 10-20 mm. long; corolla lobes about

one-fourth as long as the tube ...... Coutarea pterosperma

6. Crusea

1. Stems glabrous ......

1. Stems pubescent......

2(1) . Leaves narrowly lanceolate......

2. Leaves ovate or oblong to oblong-ovate ...... 3

3(2) Leaves large, about 9 cm. long; flowers purpl e. . . .Crusea rubra

3. Leaves small, 1-3 cm. long; flowers white. . . . Crusea brachyphylla

7. Galium

1. Flowers subtended by leaf-like bracts; fruit at maturity fleshy-

baccate, granulate ...... Galium microphyllum

1. Flowers not subtended by leaf-like bracts; fruit at maturity not

fleshy, usually minutely uncinate-hispid . . . Ga1iutri a sperrimum

8. Hoffmannia

One species......

9. Houstonia

One species...... Houstonia wrightii

10. Mitracarpus

One species...... Mitracarpus hirtus 220

11. Rand ia

t • 1. Flowers and fruit small; corolla and fruit usually 2 cm* long or

leSS .. c o .. c .» * e o o 2

1. Flowers and fruit large; corolla 2*5. cm. or much longer5 fruit

usually more than 3.0 ciru long . 5

2(1). Plants unarmed...... Randia pringlei

2. Plants armed with spines ...... 3

3(2). Throat of the corolla densely white-barbate . . . Randia thurberi

3. Throat of the corolla naked...... 4

4(3)» Lateral nerves of the leaves 5 or 6 on each side. . .Randia rose!

4* Lateral nerves of the leaves 2-4. on each side5 obscure ......

...... Randia ob cor data

5(1). Fruit densely covered with long spinelike tubercles . . 0 . . . .

...... * ...... Rand ia echinocarpa

5. Fruit smooth or nearly so..o 6

6(5). Plants armed with spines...... Randia watsonii

6. Plants unarmed * .... *...... o.. 7

7(6). Leaf blades obovate-oblong or rhombic-ovate9 usually long atten­

uate to the base ...... Randia laevigata

7. Leaf blades ovate, to ovate-elliptic, usually obtuse at the base . .

. Randia mollifolia

105. VALERIANACEAE. Valerian Family

1. Valeriana (83)

1. Perennial from a conical tap-root; corolla essentially rotate;

anthers 4-lobed...... ^Valeriana edulis subsp. edulis v 221

1. Annual from a more or less sub-napiform tap-root; corolla infundi-

buliform to subcampanulate; anthers distinctly 2-lobed * . , 0 2

2(1). Stamens and style exserted; calyx limb 5- to 6-fid or obsolete;

tap-root sometimes forked« . o ...... Valeriana apiifolia

2 o Stamens and style included; calyx limb 6- to 11-fid; tap-root more

or less unforked...... *Va1eriana sorbifolia var. sorbifolia •

106. CUCURBITACEAEo Gourd Family

1. Ovules and seeds horizontal, rarely ascending, usually numerous;

fruits medium to large; stamens normally 3 ...... 2

1. Ovules and seeds erect, ascending or pendulous, 1 to several; fruits

small to medium; stamens 1-5 ...... 5

2(1). Anther cells straight to curved, not flexuous; plants dioecious ®

. . . .6. Maximowiczia p. 223

2 o Anther cells f lexuous to conduplicate...... 3

3(2). Staminate calyx tube elongate; anthers coherent in oblong heads?

often included in and coherent to the floral tube......

...... 4. Lagenaria p. 223

3. Staminate calyx tube short; anthers free ...... 4

4(3). Staminate flowers racemose; fruit with a spongelike network of

fibers within, dryish...... 5. Luffa p. 223

4. Staminate flowers usually fasciculate or rarely solitary; fruit

without a spongelike network of fibers, fleshy ...... *

o.oooo...... 1. Cucumis p. 222

5(1). Anthers fused, forming a continuous horizontal ring around a

capitate androecium. . . . « . * ...... 2. Cyclanthera p. 222 222

5. Anthers not fused to form a horizontal ring around a capitate

androecium ...... 6 .

6(5). Ovules or seeds normally 2 or more per cell, erect or ascending »

. . o ...... , . 7

6. Ovules or seeds one, pendulous or inverted from apex or side of

ovary...... 8

7(6). Fruit smooth; staminate flowers large; filaments distinct below

...... , o ...... 8. Schizocarpum p. 223

7. Fruit echinate; staminate flowers small; filaments unitedo 0 . • « »

o ...... 3. Echinopepon p. 222

8(6). Fruit smooth; anthers 5 ...... 10. Sicyosperma p. 223

8. Fruit echinate or nearly so; anthers 3=4 « • ...... 9

9(8) o Anthers 4; staminate calyx 4-lobed. . . . .7. Microsechium p. 223

9. Anthers 3; staminate calyx 5-lobed ...... 9. S icy os p. 223

1. Cucumis

One species...... Cucumis anguria

. 2. Cyclanthera

One species...... Cyclanthera micrantha

3. Echinopepon

1. Peduncles long, in fruit 8-16 cm. long or more, springy like slender

coiled springs; fruits 1.5-2 cm. long (excluding the beak);

seeds dark brown ...... Echinopepon cirrhopedunculatus

1. Peduncles smaller, usually than 8 cm. long, not spring-like; fruits

2.5-3 cm. long (excluding the beak); seeds pale gray to light

brown...... Echinopepon wrightii 223

4-o .Lageiiaria

One species ...... Lagenaria siceraria

5 o Luffa

One species o ® « ...... • o e « « ...... Luffa operculata

6 o Maximowicz ia

One species „ ...... «, ...... , . * . ,Maximowicz ia sonorae

7 o Microsechium

One species® ® ® ...... , . , . . . . Microsechium rudefale

8. Schizocarpum

One species o o . . ® » » » » « « » . » <, » » ® « » , Schizocarpum palmeri

9« Sicyos

1 o Ovary and fruit sparingly covered with very short curved bristles;

leaves ternately digitate® e ® « ® ® » - . . » .Sicyos minimus

1, Ovary and fruit without bristles, at most pubescent; leaves

palmately 5-angled or slightly 5-lobed . . . .Sicyos parviflorus

10 o Sicyosperma

One species. ' • ...... Sicyosperma gracile

107. LOBELIACEAEo Lobelia Family

1. Hypanthium irregular, prolonged into a short blunt spur at base; two

of the calyx lobes separated from the others at or near the end

of the s p u r s ...... 1. Heterotoma p. 224

1. Hypanthium regular or essentially so, not prolonged into a spur;

calyx lobes all at one level ...... 2

2(1). Corolla white, salverform, the lobes subequal, the tube narrowly

cylindric, 50-135 mm. l o n g ...... 2. Hippobroma p. 224 224

2„ Corolla not white5 nor salverform, the tube up to 25 mm. long. . . .

o o o „ o o ...... o o ...... 3. Lobelia p . 224

1. Heterotoma

1 c Spur linear9 2-5.5 mm. long; calyx lobes linear-subulate3 the two

lower ones at or very near the tip of the spur, and separated

from the base of the hypanthium tube by the linear body of the

spur; flowers 9-12 mm* long, including hypanthium......

...oooo.oo...... Heterotoma goldmanii .

1. Spur conic, 1 mm. long or less, appearing as a small projection at

or below the middle of the asymmetrical hypanthium; calyx lobes

narrowly triangular or nearly linear, usually with a slightly

dilated base; flowers 5-9 mm. long . . . . Heterotoma cordifolia

2. Hippobroma

One species. . . . o ...... Hippobroma longiflora

3. Lobelia (80)

1. Flowers red, reddish-brown or purplish-brown, yellow or green, the

corolla never blue; flowers when straightened 27 mm. long or

longer; filament tube 18-35 mm. long ...... 2

1. Flowers essentially blue; flowers when straightened less than 27

mm. long; filament tube 1.5-7.5 mm. l o n g ...... 4

2(1). Pedicels usually shorter than the teeth of corollas, seldom more

than 1.5 cm. long; anther tube bluish, 3.5-4.5 mm. long; calyx

lobes linear subulate, 8-16 mm. long at anthesis ......

o e . . o ...... Lobelia cardinalis subsp. gramineae 225

2. Pedicels elongate, 3-10 cm. long in fruit; anther tube yellowish,

5-9 mm. long; calyx lobes triangular, 1-6.5 mm. long at

anthesis ...... 3

3(2). Leaves 0.5-1.5 cm. wide, the blades usually about 10 times as

long as wide . . . • « • • • Lobelia laxiflora var. angustifolia

3. Leaves 2-3.5 cm. wide, the blades usually about 3 times as long as

wide ...... Lobelia laxiflora var. nelsonii

4(1). Corolla tube 5-6 mm. long; filament tube 1.5-2.3 mm., long ....

.....o.o.o ...... Lobelia fenestralis

4. Corolla tube 7.0 mm. long or more; filament tube commonly more than

3 mm. long . . . o . . 5

5(4). All 5 anthers densely white-tufted at tip; flowers large, 20-28

mm. long, including hypanthium; filament tube 5-7.5 mm. long . .

o o . . . Lobelia ehrenbergii var. gracilens

5. The two smaller anthers white-tufted at tip, the three larger ones

ciliate on backs or nearly smooth; flowers smaller, 15-20 mm.

long, including hypanthium; filament tube 3.5-5.0 mm. long . » .

. e ...... * o ...... Lobelia anatina

108. C0MP0SITAE. Composite Family

Key to the Tribes:

1 0 Filaments of stamens inserted well above base of corolla tube. . . .

...... Tribe I. Veronieae p. 227

1. Filaments of stamens inserted at or very near base of corolla tube . 226

2(1). Corollas deeply bilabiate or all ligulate, only one type of

corolla present in any head...... 3

2. Corollas of disk flowers regular or nearly so, not deeply bilabiate;

heads never of ligulate flowers only . 0 4

3(2). Juice never milky; ligulate flowers none; corollas always bi­

labiate...... e, o . o • . oo. .Tribe XI. Mutisieae p. 258

,3. Juice milky; ligulate flowers only, never bilabiate......

. Tribe XII. Cichorieae p. 258

4(2). Style branches thickened toward apex; stigmatic lines only on

lower one-half of style branches . .Tribe II. Eupatorieae p. 228

4. Style branches not thickened upward; stigmatic lines approaching

or reaching summit of style branches...... 5

5(4). Anthers caudate or sagittate at base; ray flowers none; involu-

cral bracts either white-scarious or bristly ...... 6

5. Anthers not caudate nor sagittate at base; ray flowers often present

and involucral bracts rarely white-scarious or bristly .... 7

6(5). Phyllaries dry, white-scarious; plants not thistle-like; anthers

unappendaged terminally; white-wooly plants......

...... Tribe IV. Inuleae p. 238

6. Phyllaries herbaceous or coriaceous; plants thistie-like; anthers

long appendaged terminally; not white-wooly plants ......

...... Tribe X. Cynareae p. 258

7(5). Heads usually unisexual; fruit often a bur; anthers nearly or

quite distinct; rays none...... Tribe VI. Ambrosieae p. 252

7. Heads rarely unisexual; fruit not bur1ike; anthers always united

full length; rays often present...... „ 8 227

8(7). Receptacle chaffy-bracted3 at least between ray and disk flowers3

often over whole surface (sometimes greatly reduced or wanting

in Elvira and Milleria) ...... Tribe V. Helianthea'e p. 239

8 o Receptacle naked or nearly so (sometimes hairs or bristles are

present in Anthemideae and Helenieae)...... 9

9(8). Pappus of silky capillary hairs; outer involucral bracts usually

calyculate ...... Tribe IX. Senecioneae p. 257

9. Pappus of awns, paleae, bristles or wanting, rarely of silky

capillary hairs; outer involucral bracts, if shorter than inner,

rarely calyculate...... 10

10(9). Style branches of fertile flowers distinctly flattened, with an

acute to obtuse terminal appendage . .Tribe III. Astereae p. 234

10. Style branches not markedly flattened, truncate or less commonly

short-appendaged ...... o...... Q ..o .11

11(10). Phyllaries poorly or not at all imbricated, herbaceous; pappus

present or not ...... Tribe VII. Helenieae p. 253

11. Phyllaries well imbricated in several series, scarious or thin-

chartaceous, at least marginally; pappus none......

...... Tribe VIII. Anthemideae p. 257

Tribe I. Veronieae

1. Veronia

1. Heads 8-11 flowered; involucre about 7-8 mm. high; pappus pale

brown, the bristles 6.5 mm. long . . . . .Veronia serratuloides

1. Heads 3-4 flowered; involucre about 5-6 mm. high; pappus white,

outer bristles 1-1.5 mm. long, inner ones 4 mm. long ..... o

. . Veronia palmeri 228

Tribe II. Eupatorieae (121)

1. Anthers entirely destitute of apical appendage ...... 2

1. Anthers with the connective produced into an appendage at the apex .

4

2(1). Pappus of 5 squamellae, usually prolonged into hispidulous

bristles much longer than the achene . . . .1. Ageratella p. 229

2. Pappus of bristles only...... * . . . . 3

3(2). Pappus bristles dilated at tip...... 7. Decachaeta p. 230

3. Pappus bristles not dilated at tip . . . . .10. Ophryosporus p. 232

4(1). Achenes 5-angled or ribbed (rarely 4 'or.6)...... 0 5

4c Achenes 10-20-angled or ribbed (rarely 6 or 9) ...... 11

5(4). Pappus none9 or a very short c r o w n ...... 6

5. Pappus present, better developed ...... 7

6(5). Pappus entirely wanting ...... 3.1 Alomia p . 229

6. Pappus a low paleaceous crown...... 2. Ageratum p. 229

7(5). Pappus of bristles...... 8

7. Pappus of awns or squamellae or both, or sometimes reduced to a

toothed crown...... 10

8(7) . Pappus bristles plumose ...... 6. Carminatia p. 230

8. Pappus bristles capillary, not plumose ...... 9

9(8) . Pappus bristles caducous. . 11. Piptothrix p. 232

9. Pappus bristles persistent...... 8. Eupatorium p. 230

10(7). Phyllaries 5-6, uniseriate, subequal ..... 12. Stevia p. 233

10o Phyllaries more conspicuous . .. .2. Ageratum p. 229

11(4)o Achenes flattened; teeth of leaves often bristle-bearing . . , .

.....Co...... 4. Barroetea p. 229 229

11 o Achenes prismatic or t e r e t e ...... 12

12(11). Pappus bristles plumose; phyllaries sub-equal, 2-3 seriate» „ . .

• ...... 9 • Kuhnia p » 232

12. Pappus bristles capillary; phyllaries unequal, pluriseriate . . . .

. . .. - . o ...... o . . . . e .5. Brickellia p. 229

1. Ageratella

One species...... Ageratella palmeri

2 o Ageraturn

One species ...... • Ageratum corumbosum

3. Alomia

One species...... Alomia stenolepsis

4. Barroetea

One species ...... Barroetea laxiflora ,

5. Brickellia (122)

1. Heads about 60-flowered; leaves triganular-ovate, coarsely toothed;

involucre about 13 mm. high...... Brickellia simplex

1. Heads few-flowered, usually 10-24...... 2

2(1). Leaf blades linear, alternate, the margins entire ...... 3

2. Leaf blades various, never linear, usually opposite, the margins

serrate, dentate or crenate, sometimes entire in JB. pringlei . 4

3(2). Inflorescence thyrsoid or subcapitate-paniculate; heads about

10-flowered...... e @ e . Brickellia scoparia

3« Inflorescence corymbose; heads about 20-flowered . . . .

...... Brickellia af» corymbose . 230

4(2), Leaves (at least cauline) deltoid or rhombic-ovate, usually

slender petiolate; petiole commonly one-fifth the length of the

blade...... Brickellia coulteri

4. Leaves elliptic, lanceolate, lance-oblong or ovate-oblong, sessile,

or if short petiolate, the petiole stout; petiole commonly one-

tenth the length of the blade or less...... 5

5(4). Leaves truncate or cordate at base, usually membranaceous; leaves

slender petioled ...... 6

5. Leaves narrow at base, very often coriaceous; leaves sessile or sub-

sessile on stem and branches ...... Brickellia pringlei

6(5). Peduncles hispidulous or short-hirsute, not glandular; leaves

ovate or oblong-ovate, distinctly short-petiolate......

. o ...o... Brickellia betonicaefolia

6. Peduncles densely stipitate-glandular; leaves lance-oblong or ovate-

oblong, sessile, strongly cordate-clasping ......

. .Brickellia amp 1exicaulis

6. Carminatia

One species...... Carminatia tenuiflora

7. Decachaeta

One species...... Decachaeta haenkeana

8. Eupatorium

1. Involucre cylindrical, (2-) 3-5 times as long as thick; phyllaries

closely imbricated in 3-5 series ...... 2

1. Involucre normally campanulate or turbinate, rarely more than twice

as long as thick; phyllaries less closely imbricated than above.

. 3 231

2(1). Phyllaries herbaceous*-tipped tending to be squarrose; heads about

35-flowered; leaf blades lance-sagittate . Eupatoriurri sagittatum -

2 o Phyllaries appressed, not much altered at tip; heads 10-13 flowered;

leaf blades usually ovate to lance-ovate . Eupatorium bertholdii

3(1). Phyllaries conspicuously unequal, in 3 or more series . . . . . 4

3. Phyllaries subequal, in about 2 series 7

4(3)o Stems strongly quadrangular; leaves obovate^spatulate, the

petiole winged, cordate-clasping at base . • ......

...... Eupatorium quadrangulare

4. Stems not markedly quadrangular; leaves usually ovate to deltoid-

ovate, the petiole not winged, not cordate-clasping at base. . 5

5(4). Heads thistle-shaped; floret much exceeding the involucre « . . .

...... o ...... Eupatorium collinum

5. Heads not thistie-shaped .....o...... 6

6(5). Involucral bracts all acute at tip; heads about 25-flowered * . .

...... Eupatorium pycnocephalum

6. Involucral bracts obtuse or rounded at tip; heads 1-flowered ....

. . . . . o ...... Eupatorium monanthum

7(3). Leaf blades linear or lance-linear to lanceolate, the larger ones

not more than 10 mm* broad ...... 8

7. Leaf blades ovate, deltoid-ovate to oblong-ovate, the larger ones

usually much more than 10 mm. b r o a d ...... 9

8(7). Heads 3- to 7-flowered...... Eupatorium hyssopifolium

S. Heads usually 20- to many-flowered .... Eupatorium koelliaefolium

9(7). Heads 20- to many-flowered, commonly 25 ......

...... Eupatorium grandidentatum var. laxiflorum 232

9 e Heads 8- to 18 (to 20-)-flowered ...... 0 .10

10(9). Heads usually subracemose on spreading panicle branches; corolla

little longer than achenes ...... Eupatorium filicaule

10o Heads corymbose; corolla often 1.5-3 times as long as achenes . .11

11(10). Pappus half to two-thirds length of corolla ......

...... - ...... Eupatorium tubiflorum

11o Pappus at least three-fourths length of corolla « . . . . « „ . .12

12(11). Plant a shrub; petiole 10-15 mm. long; plant of High Pine

Forest, 8000 feet elevation. .... Eupatorium calaminthifolium

12. Plant an herb; petiole mostly not over 8 mm. long; plant of Oak

Forest, 3500 feet elevation. .Eupatorium occidentale

9 o Kuhnia (140)

1. Largest leaves of normal stems 2.5-5.5 cm. long; involucres 8.0-

11.7 mm. high; corollas 6.3-7.5 mm. long; achenes 4.8-5.2 mm.

long; well developed plants inclined to be bushy-branched. . . .

d-Kuhnia chlorolepis

1. Largest leaves of normal stems 5-10 cm. long; involucres 9.7-12.0

mm. high; corollas about 7.5 mm. long; achenes about 6 mm. long;

plants usually with few, virgately ascending, nearly simple

branches in the upper half ...... *Kuhnia oreithales

10. Ophryosporus

One species ..Ophryosporus scabrellus

11. Piptothrix

One species...... Piptothrix palmer! 233

12, Stevia (123) lc Inflorescence lax, the pedicels mostly equalling and often much

exceeding the involucre / . . . . * 2

1. Inflorescence or its component parts denser, heads sessile or on

pedicels averaging much shorter than the involucre » . „ . • 4

2(1), Leaves deeply parted, the segments usually linear, often again

lobed or toothed ...... Stevia trifida

2. Leaves neither deeply parted nor strongly lobed. 3

3(2). Pappus scales (as distinguished from the awns) if present,

minute, rarely 0.5 mm. long...... Stevia vise Ida

3. Pappus scales conspicuous, 1-1.5 mm. long...... Stevia pringlei

4(1) . Distinctly shrubby, at least toward the base...... 5

4. Essentially herbaceous ...... o ..... e . . . 9

5(4). Leaves sessile, or at base gradually narrowed to petioles, rarely

over one-sixth as long as the blades .. ..e...... 6

5. Leaves on well marked petioles (one-fifth to half the length of the

blade...... 8

6(5). Heads small, 5-7 (-9) mm. long; leaves rhombic-ovate; phyllaries

incurved-puberulent and sprinkled with sessile glands. . . v . 7

6. Heads larger, 9-14 mm. long; leaves oblong; phyllaries covered by

a dense spreading hispid puberulence, not gland-sprinkled. . . .

...... Stevia lemmoni

7(6). Most of the achenes 1-4 (mostly 2-3) awned......

Stevia rhombifolia var. rhombifolia

7. All achenes awnless and merely coronulate......

...... Stevia rhombifolia var. stephanocoma 234

8(5) . Blades of cauline leaves more than half as wide as long, on

petioles a third to half their length......

. . . o ...... « e . Stevia berlandieri var. adenotricha

8. Blades of cauline leaves over thrice as long as wide, on petioles

rarely above a quarter their length...... Stevia jalicensis

9(4). Leaves alternate, ...... Stevia viscida

9. Leaves (at least the main cauline) opposite, or rarely verticil late...

.10

10(9). Pappus coroniform, exaristate...... 11

10. One or more of the achenes in each head awn-bearing ...... 13

11(10). Leaves rhombic-ovate.•. . .Stevia rhombifolia var. stephanocoma

11. Leaves linear-lanceolate to ovate-oblong...... 12

12(11). Achene about 2 mm. long; leaves acuminate . Stevia karwinskyana

12 o Achene 3-4 mm. long; leaves acutish to attenuate. .Stevia plummerae

13(10)« Lower leaves oblanceolate-oblong...... Stevia palmeri

13. Lower leaves rhombic-ovate. . . Stevia. rhombifolia var. rhombifolia

f Tribe III» Astereae

1. Plants dioecious or polygamo-dioecious...... <> , 2

1. Plants not dioecious or polygamo-d ioec ious e o » 3

2(1). Plants dioecious; heads strictly pistillate or staminate. . . . .

...... 5. Baccharis p. 237

2. Plants polygamo-dioecious; pistillate heads with 1-15 central her­

maphrodite sterile flowers, rest of florets pistillate . « . . .

. . . • ...... , e . • . ,3. Archibaccharis p. 236

3(1) . Heads radiate, ligulate flowers pistillate or neuter. . . c • 4

3. Heads discoid, ray flowers never present ...... 6. Conyza p. 237 235

4(3) , Rays y e l l o w . . , , . • . = » . „ . , 5

4 e Rays white, pink, lavender or purplish, never yellow , o » o » , . 8

5(4). Ray flowers about equalling or slightly surpassing disk corollas,

inconspicuous, sometimes lacking . . « 10» Xanthocephalum p» 238

5 e Ray flowers exceeding disk corollas, usually moderately showy to

conspicuous...... 6

6(5). Ray achenes pappose; leaves small, rarely over 4 cm. long . „ * .

...... 2. Aplopappus p. 236

6. Ray achenes epappose; leaves large, 2.5-10 cm. long...... 7

7(6). Leaves linear or lanceolate; pappus of awns, reduced to a very

short crown or none; ligules not longer than tubes of ray

flowers...... ® ...... 10. Xanthocephalum pc 238

7. Leaves ovate-lanceolate; pappus, at least in part, of capillary or

scabrous bristles; ligules longer than tubes of ray flowers. .. *

o 9 ...... 8. Heterotheca p. 238

8(4). Rays mostly oblong, usually 2 mm. wide or more; involucral bracts

strongly graduate...... 9

8. Rays mostly oblong, usually 2 mm. wide or more; involucral bracts

subequal, usually not strongly graduate...... 10

9(8) . Plants perennial, usually with rhizomes'or fibrous roots, or if

annual, leaves entire or essentially so...... 4. Aster p. 236

9. Plants annual or biennial from a weakly developed tap-root; lower

leaf blades of primary stems irregularly lobed or merely dentate

with the upper becoming successively reduced and entireo ....

...... 9. Machaeranthera p. 238 236

10(8) o Pappus a minute setulose crown ...... 1. Achaetogeron p« 236

10o Pappus of subequal capillary or scabrous bristles 3 sometimes with

an outer series of short squamellae...... 7. Erigeron p„ 237

1. Achaetogeron

1 o Leaves pinnately-parted, the segments l i n e a r......

. Achaetogeron pinnatifidum

1. Leaves not pinnately-parted...... 2

2(1). Perennial plants; lower leaves narrowly spatulate, usually sharp-

toothed, upper leaves linear, entire . . . .Achaetogeron affinis

2. Annual plants; leaves linear or subspatulate, entire ......

...... Co...... Achaetogeron palmer!

2. Aplopappus (39)

One species o ...... ^Aplopappus stenolobus

3« Ar chiba c char is

One species o . . . . = ...... Archibaccharis serratifolia

4. Aster

1. Plants stipitate-glandular; leaves oblong or lanceolate-oblong . . „

...... Aster gentry!

1. Plants not stipitate-glandular, usually glabrous or nearly so. . . 2

2(1). Plants suffrutescent, woody at least at base, usually spine-

bearing; leaves not grasslike, usually deciduous .Aster spinosus

2. Plants herbaceous, not spine bearing; leaves usually grasslike, per­

sistent o . . o ...... o...... Aster exilis 237

5. Baccharis

1. Leaves entire to serrate, the teeth remote (1 to 3 per cm.). e . . .

^ ‘...... Baccharis heterophylla

1 e Leaves closely serrulate (teeth 5 to 10 per cnu) . . . o ..... 2

2(1). Leaves linear to narrowly oblanceolate or linear-oblanceolate . 0

o o ... o ... o ...... Baccharis thes ioides

2. Leaves lanceolate...... Baccharis alamosana

6. Conyza

One species...... Conyza sophiaefolia

7. Erigeron

■1. Rays very short and inconspicuous, not or only slightly surpassing

the pappus ...... 2

1. Rays present and conspicuous, much surpassing the pappus ..... 3

2(1). Plants loosely arachnoid-pilose, also glandular, especially on

the leaves and heads; leaves sessile and somewhat clasping,

lanceolate or oblong”lanceolate...... Erigeron schiedeanus

2. Plants sparingly to densely hispid, not glandular; leaves not

clasping, linear-oblong to linear-oblanceolate ...... e e .

„ o ...... Erigeron canadensis

3(1). Leaves (except sometimes the uppermost) all deeply pinnatifid

with usually narrow lobes...... Erigeron oreophillus

3. Leaves entire or toothed...... » 4

4(3). Perennial plants; involucre large, 5-15 mm. long......

...... o ..... o . . .Erigeron karwinskianus

4. Annual, or at least biennial plants; involucre small, not more than

5 mm. long ...... 5 238

5(4). Plants annual; radical and cauline leaves ovate to broadly

spatulate; rays about 50 ..... T ■ o... . . Erlgeron alamosanum

5. Plant annual or biennial; radical leaves broadly oblanceolate to

spatulate, cauline leaves linear or oblanceolate; rays 75-150. .

...... Erigeron divergent

8. Heterotheca

One species...... Heterotheca subaxillaris

9. Hachaeranthera (156)

One species...... 4-Machaeranthera tenuis

10'. Xanthocephalum

1. Leaves lanceolate to oblong-lanceolate, 5-20 mm. wide; heads crowded

in cymose panicles, the peduncles stipitate-glandular; pappus

in the ray achenes none or reduced to an obscure border, in the

disk achenes of unequal, basal squamallae or paleae......

...... Xanthocephalum gymno s permo ides

1 o Leaves chiefly linear, 2-4 mm. wide; heads mostly solitary at the

tips of cymosely arranged glabrous branches; pappus a short

undulate crown ...... Xanthocephalum wrightii

Tribe IV. Inuleae

1. Gnaphalium

1 o Pappus bristles connate in a ring at base. . . .Gnaphalium purpureum

1. Pappus bristles distinct, falling separately ...... 2

2(1). Leaves gray tomentose above as well as beneath, sometimes only

thinly so...... o 3 239

2, Leaves green and often glandular pubescent above, whitish-tomentose

beneath...... » ...... , . , . . . . . 4

3(2). Leaves not at all or only obsoletely decurrent; phyllaries with

white tips or slightly tinged with straw color, mostly obtuse. .

• ...... » . . . o . . . . o o e Gnaphalium wrightii

3, Leaves definitely decurrent, or at least with broad adnate auricles;

phyllary tips brownish or purple-tinged, mostly acute or

acuminateo . . , • . , . » » . . . * . . Gnaphalium arizonicum

4(2). Involucral bracts dull white, not shining; leaves narrowly linear

...... 5

4 o Involucral bracts straw-colored or whitish, thin-scarious, shining;

leaves oblong-linear to linear-lanceolate. ••••••••••■• 6

5(4). Heads in compact terminal glomerules; plants of Pine Forest, 6000

■ feet elevation . . 0 ...... Gnaphalium leptophyllum

5. Heads in openly branched glomerules; plants of Short-tree Forest,

2000 feet elevation...... Gnaphalium leucophyllum

6(4). Bracts lance-ovate; plants of Short-tree and Oak Forest, 1000-

3500 feet elevation...... Gnaphalium attenuatum

6. Bracts broadly ovate; plants of Pine Forest, 5000-7500 feet

elevation...... Gnaphalium bourgovii

Tribe V. Heliantheae

1. Heads 1- or 2-flowered, glomerate, the proper involucres gamophyllus

.... o ..... o ... 6 ...... 15. Lagascea p . 247

1. Heads with more numerous flowers, or if 1- or 2-flowered, then

involucre not gamophyllus. . 0 . 2 240

\ 2(1)o Disk flowers perfect but all of them sterile, their ovules

abortive...... 3

2. Disk flowers sterile (part of them sometimes sterile in Sclero-

carpus and Coreocarpus) .10

3(2) . Chaffy receptacular bracts greatly reduced or wanting . , «, . . 4

3 o Chaffy receptacular bracts not reduced, often equalling involucres o

...... 5

4(3). Involucre of one large bract opposing 2-3 smaller ones; heads

greatly flattened parallel to opposing bracts; ligule of fertile

flower entire or nearly so; heads arranged in racemes or

panicles <, «, „ ...... , 8» Elvira p , 246

4 o Involucre of subequal bracts, these not opposed; heads not

flattened; ligule of fertile flower small, but noticeably 3-

toothed; heads in glomerules or fascicles. „ 17» Milleria p. 248

5(3). Inner phyllaries sac-like and completely enclosing the ray

achenes; achenes short and thick, not flattened......

...... o ...... 16: Melampodium p. 247

5. Inner phyllaries plane or nearly so, not enclosing the ray achenes;

achenes usually flattened...... 6

6(5). Corolla of ray flowers persistent and falling with achenes,

leathery or indurate ...... 27. Tragoceros p. 250

6. Corolla of ray flowers deciduous before achenes fall, not leathery

or indurate...... 7

7(6). Achenes of ray flowers free from adjacent disk flowers, falling

separately ...... 11. Guardiola p. 247 241

7. Achenes of ray flowers attached to 2 or 3 adjacent disk flowers and

falling with t h e m ...... 8

8(7). Heads radiate, ray flowers with relatively large conspicuous

ligules, 10-15 mm. long...... 1. Berlandiera p. 244

8. Heads discoid or apparently so, ray flowers none or with inconspic­

uous ligules, 0.5-1 mm. long ...... 9

9(8). Heads erect; achenes glandular-puberulent and more or less

arachnoid-villous, keeled on inner face. . 20. Parthenium p. 248

9. Heads nodding; achenes glabrous, keel lacking. 19. Parthenice p. 248

10(2). Ray flowers persistent on the achenes...... * .11

10. Ray flowers deciduous from the achenes...... « .12

11(10). Disk achenes strongly compressed or markedly angled; phyllaries

dry, strongly graduate; leaves all entire. . .33. Zinnia p. 252

11o Disk achenes terete, or obtusely angled; phyllaries herbaceous at

tips, little graduated; large leaves usually shallowly to

sharply toothed, smaller ones entire . . . .12. Heliopsis p. 247

12(10). Disk pappus of about 20 fimbriate squamellae or paleae, or

often of plumose awns or squtnaellae...... 13

12. Disk pappus a mere crown or cap, or of a few teeth, awns or : 1

bristles, or absent, or if scales, not plumose and fewer than

15 ...... o ...... 14

13(12). Squamellae of the pappus with thick midribs and fimbriate

margins...... 10. Galinsoga p. 247

13. Squamellae of the pappus aristate-acuminate, plumose ciliate. . * .

' . o . . o . o o o o ...... 28. Tridax p. 250 242

14(12). Achenes flattened dorsiventrally• •«••••.•••••• ,15

14e Achenes (at least those of the disk) flattened laterally or not

flattened at all ...... * . . , ,19

15(14). Leaves alternate; receptacle conical to slightly convex; pappus

none , ...... 14. lostephane p. 247

15o Leaves opposite; receptacle flat or nearly so; pappus present or

nOt, ...... 0.16

16(15). Perennial with a more or less tuberiferous root; heads radiate*

at anthesis mortly 4.5-8 cm. wide, but occasionally much larger;

paleae large; style branches of the disk florets running into

long bearded linear or sublanceolate appendages; achenes wing­

less, commonly awnless ...... 6. Dahlia p. 246

16. Otherwise, in one or usually in several respects. . . , . . . . *17

17(16), Phyllaries subequal, usually submembranous„ ...... , , .

. , 4. Coreocarpus p. 246

17. Phyllaries in 2 unlike series, the outer mostly herbaceous, the

. inner broader and membranous ...... o ... » ,18

18(17). Achenes conspicuously elongate, but beakless. .2. Bidens p. 244

18. Achenes definitely beaked ...... 5. Cosmos p. 246

19(14). Chaff of the receptacle merely awns or bristles ......

. o o ...... 7. Eclipta p. 246

19. Chaff of concavo-convex or folded pales ...... 20

20(19). Disk achenes (sometimes also the ray achenes) closely invested

by the pale which appears as 'an outer coat ...... 21

20. Disk achenes merely subtended by a pale or loosely enfolded by it .

...... 22 243

21 (20). Involucre in 2 unlike series, the outer phyllaries herbaceous,

the inner submembranous, or if not, the hairs not hispid and

spreading...... 18. Montanoa p. 248

21. Involucre all alike, usually herbaceous, the hairs hispid and

spreading. . * . . • . • . « . . , . . 24* Sclerocarpus p. .249

22(20). Receptacle columnar . . . o . . o ..... 23. Ratibida p» 249

22. Receptacle flat or convex, sometimes low-conic, never columnar« .23

23(22). Pappus of disk achenes consisting of 4 to many free, usually

equal or sub equal awns or squamellae...... 24

23. Pappus of disk achenes of 2 or 3 awns without or with squamellae,

or wanting ...... 25

24(23). Pappus of deciduous setiform awns . . . . 21. Perymenium p. 248

24. Pappus of persistent paleaceous awns or squamellae. 3. Calea p. 246

25(23). Achenes strongly compressed, flat or flattish ...... 26

25. Achenes thickened ...... 29

26(25). Margins of mature achenes conspicuously white-winged or densely

long ciliate ...... 27

26. Margins of mature achenes not conspicuously white-winged or ciliate

(sometimes white-edged in Zexmenia)...... 28

27(26). Achene margins conspicuously ciliate...... 9. Encelia p . 247

27. Achene margins conspicuously white-margined, not ciliate......

...... o . .29» Verbesina p. 250

28(26). Annuals; phyllaries narrow, usually lance-ovate to lance-linear

and with or without pappus ...... 23. Simsia p. 249 244

28. Perennial; phyllaries broad5 usually ovate or ovate-oblong; pappus

present...... « . 32. Zexmenia p. 251

29(25) . Ray flowers pistillate...... o30

29. Ray flowers neutral or wanting. .31 .

30(29). Leaves opposite, or the upper-most sometimes alternate in

Zexmenia hispida; achenes usually acutely margined or winged . «

o ...... 32. Zexmenia p. 251

30e Leaves alternate; achenes usually not acutely margined or winged. »

o ...... 31. Wedelia p. 251

31(29). Heads large, 5-15 cm. long; peduncles fistulose and.markedly *

thickened below heads...... 26. Tithonia p . 249

j 31. Heads much smaller; peduncles usually not fistulose and thickened

below heads...... * .32

32(31). Pappus none ...... v ...... o ® . .33

32. Pappus present. » .34

33(32). Leaf blades mostly o v a t e ...... 13. Hymenostephium p. 247

33. Leaf blades linear, lanceolate to linear-lanceolate ......

...... 30. Viguiera p. 250

34(32). Phyllaries 3-7 seriate, or if 2-se.riate pappus absent; leaves

usually throughout the stems ...... 30. Viguiera p. 250

34. Phyllaries 2-seriate; leaves mostly basal „ .22. Pionocarpus p. 249

1. Berlandiera (111)

One species...... Berlandiera lyrata var. macrophylla

2. Bidens (138)

1. Heads conspicuously radiate, the ray florets for the most part

yellow or orange 2 ' 245

1 o Heads discoid or subradiate, or if conspicuously radiate, then the

ligules white or rosaceous, never true yellow. e 6

2(1). Ray florets reddish-orange...... Bidens sambucifolia

2 6 Ray florets yellow ...... „ „ 3 '

3(2). Annual or biennial „ « « » ...... o 4

3 o Perennial or apparently so.. . . . o . • ...... 5

4(3). Principal leaves commonly undivided, or 3-5 parted, very rarely

b ip innate...... Bidens aurea

4. Principal leaves 2- or sub- 3-pinnate...... Bidens ferrulaefolia

5(3). Ligulate florets usually 5; outer involucral bracts 4-5 mm. long.

...... Bidens insolita

5. Ligulate florets 7-9; outer involucral bracts 9-12 mm. long. ....

...... Bidens gentry!

6(1). Achenial aristae 3-5, regularly one or two erect, the others

reflexed ...... *Bidens riparia var. refracta

6. Achenial aristae lacking, or if present none reflexed...... 7

7(6). Leaf segmentscommonly linear...... 8

7. Leaf segments (or the blade of simple leaves) narrowly lanceolate or

wider ...... 9

8(7). Disk florets few, commonly 8-13 ...... Bidens heterosperma

8. Disk florets much more numerous ...... Bidens. tenuisecta

9(7) . Achenes few, commonly 6-8 ...... Bidens oligocarpa

9. Achenes numerous, commonly more than 15...... 10

10(9). Heads discoid...... Bidens pilosa

10. Heads radiate, the ligulate florets present, but whitish or more or

less rosaceous, not true yellow. . . .Bidens pilosa var. radiata 246

3. Calea

1 - Shrub3 leaves ovate-oblong or oblong-lanceolate3 not narrowed at .

the base . . . . * ...... Calea scabrifolia

1. Herb; leaves oblong, narrowed at the base...... Calea palmer!

4. Coreocarpus

1. Plants herbaceous annual ...... * ......

o...... ^Coreocarpus parthenioides var. parthenioides

1. Plants suffrutescent perennials.Coreocarpus arizonica"var. pubescens

5. Cosmos (139)

1. Perennial plants « ...... • ...... » . . 2

1. Annual plants ...... 3

2(1). Leaves entire, linear . . . Cosmos 1inearifo1ius var. magnifolius

2. Leaves usually parted, never entire...... Cosmos pringlei

3(1). Achenial aristae antrorsely hirtellous-barbellate .Cosmos exiguus

3. Achenial aristae retrorsely barbellate ...... 4

4(3). Ligulate florets sulphureous or reddish-yellow, usually 1.8-2.8

cm. long ...... Cosmos sulphurous

4. Ligulate florets whitish or rosaceous, not yellow, usually 5-9 mm.

long ...... Cosmos parviflorus

6. Dahlia (143)

One species Dahlia coccinea

7. Eclipta

One species...... Ecliptaalba

8. Elvira

One species...... *Elvira biflora 247

9 * Bncelia

1> Heads several to many, paniculately arranged; branches of inflores­

cence glabrous or nearly so...... Encelia farinosa

1. Heads few or solitary; peduncles pubescent . . . Encelia halimifolia

10* Galinsoga

One species...... e .Galinsoga parviflora

11. Guardiola

1. Leaves broadly ovate to deltoid-ovate, sessile or on short petiole

1-4 mm. long ...... Guardiola platyphylla

1. Leaves lance-oblong to linear; petiole usually more than 5 mm. long.

...... Guardiola arguta

12. Heliopsis

One species...... * ...... Heliopsis parvifo 1 ia

13. Hymenostephium

One species ...... Hymeno stephium superaxillare

14. lostephane (137)

One species...... lostephane heterophylla

15. Lagascea

-1, Leaves sessile, cordate-clasping ......

...... Lagascea helianthifolia var. suaveolens

1. Leaves petiolate, this about 3-9 mm. long. . . . .Lagascea decipiens

16. Melampodiutn

1. Fruiting bracts not exceeding the enclosed achenes, nor developed

into a cup or. hood ...... Me lamp odium perfoliatum

1. Fruiting bracts exceeding the enclosed achene and developed at the

summit into a cup or hood...... 2 248

2(1). Ray flowers inconspicuouss 1-2 mm. long, barely equalling or

usually shorter than involucral bracts; peduncles mostly shorter

than subtending leaves, or heads subsessile. „ .

...... Melampodium longicorne ‘

2. Ray flowers conspicuous, 4-6 mm. long, usually exceeding the invo­

lucral bracts; peduncles often surpassing subtending leaves. . 3

3(2). Leaves linear to oblong, sparingly pubescent to hirsute beneath*

not sericeous...... +Melampodium appendiculaturn

3. Leaves pinnatifid, densely sericeous beneath . .Melampodium sericeum

17. Milleria

One species...... > . Milleria quinqueflora

18. Montanoa

1. Heads small, 16 mm. wide or less, the rays 2-5 in number; pales

densely silky-villous...... Montanoa rose!

1. Heads medium size, about 2.5 cm. wide, the rays 7-10 in number;

pales abruptly and shortly uncinate-cuspidate, not silky ....

. . . . o ...... o o . * . * * . Montanoa patens

19. Parthenice

One species...... Parthenice mollis

20. Parthenium (124)

One species...... ^Parthenium tomentosum var. stramonium

21. Perymenium

1. Leaves green above, densely and finely canescent-tomentose beneath .

...... Perymenium stenophyllum

1. Leaves green beneath as well as above. . . .Perymenium subsquarrosum 249

22. Pionocarpus

One species. . . o * ...... , « . » . .^Pionocarpus madrensis

23. Ratibida (119)

One species • ...... » .. . . . » . . .^Ratibida mexicana

24. Sclerocarpus

One species...... Sclerocarpus spathulatus

25. Simsia (6)

1 o Petiole bases connate into conspicuous foliaceous stipule-like ap­

pendages ...... Simsia.setosa

1. Petiole bases sometimes auriculate, not connate at base into

foliaceous stipule-like appendages ...... 2

2(1). Achenes appressed pubescent, pappus of 2 upwardly pubescent awns

fimbriate at base...... *Simsia foetida var. foetida

2. Achenes glabrous, epappose ...... *Simsia foetida var. decipiens

26. Tithonia (9)

1. Pappus present...... • • 2

1. Pappus none. * ...... * . . . «, 3

2(1). Plants herbaceous, annual; stems sparsely hispid-pilose; pappus

awn solitary, 5.5-8 mm. long ...... Tithonia thurberi

2. Plants shrubby, perennial; stems densely and canescently pilose-

tomentose; pappus awns 1-2, 2-3 mm. long, or rarely wanting. . .

. . o . . . Tithonia fruticosa

3(1). Leaves lance-ovate to ovate; involucre 9-12 mm. high; disk 9-12

mm. high . e « .Tithonia calva var. lancifolia

3. Leaves linear-lanceolate to narrowly lance-ovate; involucre 7.5-9

mm. high; disk about 5 mm. high. . Tithonia auriculata 250

27. TraRoceros

One species...... Tra^oceros zinnioides

28. Tridax (115)

1 o: Perennial plants; stems procumbent . Tridax procumbens

1. Annual plants; stems e r e c t ...... Tridax tenuifplia

29o Verbesina

1. Heads 3; leaves mostly basal in a basal rosette, spatulate, not

decurrent; plants of High Pine Forest, 8000 feet elevation » » o

o.o e o o o. .V o o o . . . . « o » . . , . .Verbesina callilepis lo Heads numerous; leaves usually throughout the stem, ovate to rhom=-

bic-ovate, decurrent through the internodes, making a 4-winged

stem; plants of Short-tree Forest, 3000 feet elevation « . «. * »

...... oo.ooooo.e Verbesina gentryi

30 * Viguiera (8)

1. Pappus none...... * . . . » ...... 2

1. Pappus present ...... 3

2(1)o Leaves lanceolate to linear lanceolate, 4-14 mm. wide; heads

large, the disk 6-14 mm. thick...... Viguiera longifolia

2 e Leaves linear of linear-lanceolate,1.5-3 mm. wide; heads small, the

disk 6-8 mm. thick » . . o ...... Viguiera annua

3(1)c Involucre 3-seriate, not strongly ciliate, hispidulous to sub-

canescently appressed pilose on b a c k ......

...... *Viguiera dentata var. lancifolla

3 o Involucre 6-7 seriate, strongly ciliate, glabrous on back......

...... Viguiera montana 251

31. Wedelia

One species...... Wedelia acapulcensis

32. Zexmenia (58)

1. Mature achenes winged, more or less constricted near its summit,

forming a sort of neck ...... Zexmenia hispida

1. Mature achenes not definitely winged9 nor constricted near its

summit ...... o 2

2(1). Intermediate scales (squamellae) of the pappus on the disk achene

at least 1 mm. long ...... Zexmenia seemannii

2. Intermediate scales minute, less than 0.5 mm. long or entirely

want ing ...... 3

3(2). Heads few, in terminal 3-headed cymes or solitary ...... 4

S.. Heads numerous z» ...... o ...... 5

4(3). Herbaceous plant; ray flowers about 12; awns of the disk achenes

shorter than the body of the achene. . . . .Zexmenia podocephala

4. Shrub; ray flowers 5-10; awns of the disk achenes longer than the

body of the achene ...... Zexmenia fruticosa

5(3). Achenes 4-5 mm. long, those of the ray flowers 3-awned; awns

longer than the body of the disk achenes, at maturity exceeding

the involucres . <> ...... Zexmenia ceanothifolia

'5. Achenes about 3 mm. long,those of the ray flowers with only one

awn; awns shorter than the body of the disk achenes, at maturity

not exceeding the involucre...... Zexmenia fasciculate 252

33. Zinnia (150)

1. Heads campanulate; rays yellow or red to scarlet; lobes of disk

flowers densely velutinous; leaves lance-linear to broadly

ovate or elliptic. > ...... ^Zinnia peruviana

1. Heads hemispheric; rays bright orange; lobes of disk flowers smooth9

without long, dense acute hairs; leaves linear to lance-linear *.

» ...... e ...... •'"Zinnia angustifolia

Tribe VI. Ambrosieae

1. Pistillate involucres burlike with spines; leaves or their divisions

not linear or sub filiform...... 1. Ambrosia p. 252

1. Pistillate involucres not burlike, bearing broad scarious wings* . .

...... « .2. Hymenoclea p. 252

1. Ambrosia (104)

1. Plants herbaceous; spines straight, not uncinate ......

» ...... ^Ambrosia acanthicarpa

1. Plants shrubby; spines usually uncinate at the tips...... 2

2(1). Leaf blades lanceolate-attenuate, reticulate-veined; staminate

involucres stalked, stalks to 14 mm. long; fruit spines numerous

(usually more than 30) ...... ^Ambrosia ambrosioides

2 e Leaf blades ovate-cordate to broadly lanceolate, 3-veined; staminate

involucres stalked to subsessile, stalks to 4 mm. long; fruit

spines 6-30e ...... ^Ambrosia cordifolia

2. Hymenoclea

1. Wings of fruit spirally arranged, or in several series; diameter of

winged fruit 8-10 mm...... Hymenoclea salsola 253

1. Wings of fruit usually in a single equatorial whorl; diameter of

winged fruit not more than 5 mm* ...... Hymenoclea monogyra

Tribe VII. Helenieae

1 o Involucral bracts comparatively broad, imbricated in 3-5 series;

plants fleshy...... 5. Jaumea p. 254

1. Involucral bracts not markedly broad, subequal in 1-2 (-3) series;

plants usually not conspicuously fleshy...... a . 2

2(1). Achenes flattened, but not angled, ribs or veins marginal ®

...... 7. Per.ityle p . 255

2. Achenes distinctly 3-5 angled, or if angles obscure, then obconic

and with distinct nerves on faces ...... 3

3(2). Leaves and phyllaries dotted or striped with translucent oil

glands ...... o 4

3. Leaves and phyllaries sometimes impressed punctate, but not with

translucent oil glands ...... 7

4(3). Involucral bracts in 2, more or less equal series, united at base

or almost to the apex, usually calyculate; pappus squamellae

usually 10-20o ...... 1. Dyssodia p. 254

4. Involucral bracts distinctly in 1 s e r i e s ...... ® . . . 5

5(4). Style branches of perfect flowers short, often dilated at apex,

truncate or rounded; leaf margins with a few stiff hairs near

the base 6. Pectis p. 254

5. Style branches of perfect flowers elongate; leaf margins without

stiff bristles ...... 6

6(5). Rays present; pappus of squamellae...... 10. Tagetes p. 256

6. Rays none, pappus of bristles...... 8. Porophyllum p. 256 254

7(3). Heads discoid, ray flowers none o . » . • • * „ * „ .. 8

7. Heads radiate, ray flowers present ...... 9

8(7). Pappus wanting; achenes about 10-ribbed . . . .2. Flayeria p, 254

8 o Pappus of paleaceous scales, midnerve prolonged into an awn; achenes

4-»angled...... 4. Hymenothrix p. 254

9(7). Phyllaries usually reflexed...... 3. Helenium p. 254

9 o Phyllaries erect ...... 9. Schkuhria p. 256

1. Dyssodia (149)

1 e Bracts of calyculum pectinate, glandulose; phyllaries with conspic­

uous corntite appendages...... o ...o ... *

o . . . .^Dyssodia porophylla subsp. cancellata var. cancellata

1. Bracts of calyculum entire, glandless; phyllaries without cornute

appendages . .Dyssodia anomala

2 o Flaveria

One species...... * .Flaveria oppositifolia

3. Helenium

One species. . » ...... Helenium laciniaturn

4. Hymenothrix (155)

One species...... *Hymeno thrix paImeri

5. Jaumea

One species...... Jaumea peduncular is

6. Pectis (132)

1. Pappus of well developed squamellae ...... Pectis prostrata

1. Pappus (at least in the ray flowers) of bristles or awns, only

occasionally paleaceous at the base, rarely with an additional 255

outer set of minute squamellae, or rarely reduced to a mere

crown» ...... o o ••• ...... o . o . o . o 2

2(1). Pappus of slender, filiform bristles, or rarely dilated below,

erect, or a mere c r o w n ...... 3

2» Pappus (at least of the ray flowers) of subulate stout awns. . . . 6

3(2). Pappus bristles usually 15 or more, at least in the disk flowers»

...... 4

3. Pappus bristles few, 1-4, or represented by a mere crown . . . .' . 5

4(3). Perennial plants...... Pectis stenophylla

4. Annual plants...... Pectis palmeri

5(3). Bracts more or less acuminate; heads on peduncles 1-3 cm. long;

disk flowers about 10...... Pectis uniaristata

5. Bracts obtuse; heads on peduncles 2-8 cm. long; disk flowers about

5...... Pectis filipes

6(2). Plants annual, or rarely perennial; leaves usually with basal

bristles; awns more or less spreading...... Pectis coulteri

6. Plants definitely perennial from a woody rootstock; leaves normally

without basal bristles; awns, if present, erect. Pectis imberbis

7. Perityle (28, 116)

1. Pappus awns 2 ...... 2

1. Pappus awn 1 or lacking...... 3

2(1). Plants perennial, grayish-puberulent; leaves coarsely dentate,

neither incised nor lobed -PPerityle microcephala

2. Plants annual, glandular-puberulent; leaves incised or deeply lobed.

. e ...... *Perityle microglossa 256

3(1). Plants annual from a slender taproot„ . . . *Perityle californica

3. Plants perennial . » . . . 0 ...... 4

4(3) . Rays white...... -PPerityle microcephala

4. Rays ye l l o w ...... „ . 5

5(4). . Larger leaves not more than 2.5 cm. long and broad; heads small9

7-9 mm. long; ray flowers 6-10 ...... 4-Perityle gentryi

5. Larger leaves more than 2.5 cm. long and broad; heads large3 more

than 9 mm. long; ray flowers about 30. . . .4-Perityle cordifolia

8. Porophyllum

1. Leaf blades broadly oval to ovate; involucre 18-22 mm. high. . . . .

. . o .... o * . Porophyllum macrocephalum

1. Leaf blades, not as above . . . © ...... © . . . . ® . . ® . 2

2(1). Plants perennial; leaves filiform to narrowly linear; involucres

greenish to purplish ...... Porophyllum gracile

2. Plants annual; leaves lance-linear to oblanceolate; involucres

dark purple.\ ...... Porophyllum, coloratum

) 9. Schkuhria (40)

1. Disk flowers about 5 9 rarely more; achenes long villous on the

angles . Schkuhria anthemoidea

1. Disk flowers 5-8; achenes short villous on the angles......

...... ^Schkuhria pinnata var. virgata

10. Tagetes (131)

1 & Leaves simple...... 2

1. Leaves pinnatifid...... 3 257

2(1)o Perennial plants; ligules distinctly exserted, orbicular; heads

in rather dense flat-topped cymes» „ e • . . » 0 .Tagetes-lucida

2„ Annual plants; ligules scarcely exceeding the involucre; heads in

open cymes « . « <> . » ...... • « „ . o .Tagetes pringlei

3(1). Ligules large, 1 cm. long or more Tagetes alamensis

3 o Ligules short, 1.5-6 mm. long...... 4

4(3). Leaflets linear-filiform, normally entire . . . Tagetes filifolia

4. Leaflets lanceolate, serrate to pectinately incised...... « . 5

5(4). Leaflets merely serrate; ligules cuneate-oblong, 5-6 mm. long .

Tagetes jaliscana

5. Leaflets pectinately incised; ligules sub-orbicular, about 2 mm.

long ...... Tagetes subulata

Tribe VIII. Anthemideae

1. Artemisia (65)

One species...... 4Artemisia ludoviciana subsp. sulcata

Tribe IX. Senecioneae

1. Heads radiate, ray flowers present ...... 2. Senecio p. 258

1. Heads discoid, ray flowers none ...... 1. Odontotrichum p. 257

1. Odonto trichum (113)

1. Basal leaves shallowly dentate or entire; inflorescence very com­

pact, globose, about 2.5 cm. long and broad......

...... *Odontotrichum globosum

1. Basal leaves pinnatisect; inflorescence paniculate or corymbose,

about 11-20 cm. long and broad . . . *0donto tr ichum decompositum 258

2. Senecio

One species ...... ‘ « Senecio hartwegii

Tribe X. Cynareae

lo Centaurea

One species. e «, . • . • * Centaurea americana

Tribe XI. Mutisieae lo Plants herbaceous; involucral bracts in 3- to many series. V .

- . ' r ...... o o o o . o o 1. Perezia- p. 258

1. Plants shrubby; involucral bracts in 2 series. . . .2. Trixis p. 258

1. Perezia

1. Phyllaries all attenuate-acuminate; heads 4-6 flowered; upper part

of tube and segments of corolla usually glandular-papilloseo « •

* o ...... o ...... Perezia thurberi

1. Phyllaries not attenuate-acuminates but more abruptly acuminate;

heads 19-22 flowered; corolla essentially glabrous ......

...... Perezia montana

; 2. Trixis

1. Leaves conspicuously glandular beneath ...... Trixis californica

1. Leaves not glandular beneath ...... Trixis wrightii

Tr ib e.XII. Cichorieae

1. Achenes columnar3 or narrowed upward, but not beaked ......

. . o . . o ...... o ...... 1. Hieracium p . 258

1. Achenes beaked ...... « .2. Pinaropappus p. 259

1. Hieracium

1. Stem (scape) leafless5 or if with 1 or 2 small leaves or bracts,

then these not at all clasping; achenes about 5 mm. long$ 259

conspicuously tapering from the base to the summit . „ « . * ; .

. . o e o o o . . e . „ , • o e o o . o o . . .Hieracjum fendleri

1. Stem leafy, the leaves with a broad, more or less clasping base;

achenes 3.5-4.5 mm, long, columnar or very gradually attenuate

toward the summit...... Hieracium lemmoni

2. Pinaropappus

One species • ...... • . ,Pinaropappus junceus

) APPENDIX

NOMENCLATURE CHANGES

*Acacia angustissima (Mill) Kuntze subsp. angustissima

Acacia angustissima (Mill) Kuntze

^Aeschynomene vlllosa Poir var. longifolia (Micheli) Rudd

Aeschynomene atnericana L 0

4-Aeschynomene villosa Poir var. villosa

Aeschynomene americana Lo

*A%astache barberi Epl„

Agastache ionocalyx (Robins) Standi»

+Agastache pallidiflora Rydb. subsp» mearnsi Lint & Epling

Agastache palmeri (Robins) Standi«

:*Agave pacifica Trel,

Agave yaquiana Trel.

+ Agave polianthifolia Gentry

Agave hartmani Wats.

*Agave shrevei subsp. shrevei .

Agave shrevei Gentry

*Agave vilmoriniana Borger

Agave mayoensis Gentry

^Alchemilla aphanoides Linn, var. subalpestris (Rose) Perry

Alchemilla subalpestris Rose

260 261

*Allionia incarnata L e

Wedeliella incarnata (L.) Cockerell.

^Allium kunthii Don

Allium scaposum Benth«

^Altamiranoa chihuahuense (Wats e ) Rose

Sedum chihuahuense Wats«

^Ambrosia acanthicarpa Hook

Franseria acanthicarpa (Hook<,) Cav.

*Ambrosia ambrosioides (Cav.) Payne

Franseria ambrosioides Cav*

^Ambrosia cordifolia (Gray) Payne

Franseria cordifolia Gray

*Anoda cristata (Lo) Schlecht*

Anoda hastata Cavo

^Antirrhinum kingii Wats, var. watsoni (Vasey & Rose) Munz

Antirrhinum watsoni Vasey & Rose

*Aplopappus stenolobus Greene

Aplopappus tenuilobus Gray

*Arceuthobium vaginaturn (H.B.K.) Eichler

Razoumofskya vaginata (HoBoKo) Kunze

•fArgemone ochroleuca Sweet subsp. ochroleuca

Argemone mexicana L 0

^Artemisia ludoviciana Nutt, subsp. sulcata (Rydb.) Keck

Artemisia mexicana Willd,

*Asclepias hypoleuca (Gray) Woodson

Gomphocarpus hypoleucus Gray *Asclepias leptopus I „ M. Johnston "

Asclepias suffrutex Standi.

^Asterohyptis seemanil (Gray) Epling

Hyptis seemanii Gray

*Asterohyptis stellulata (Benth.) Epling

Hyptis stellulata Benth.

-fAstragalus gentry! Standi.

Astragalus nuttalianus DC

*Begonia gracilis H.B.K. yar. martiana A. DC

Begonia martiana Link & Otto

*Begonia gracilis H.B.K. var. nervipilosa A. DC

Begonia gracilis H.B.K.

*Bidens riparia var. refracta (Brand.) 0. E. Schulz.

Bidens refracta Brand.

*Bletia gracilis Lodd. var. roezlii (Reichb. f.) L.

Bletia roezlii Reichenbach

“Bletia reflexa Lindley

Bletia amabilis Schweinfurth

*Bouvardia ternifolia (Cay.) Schlecht.

Bouvardia glaberrima Engelm.

“Bromus anomalus Rupr. ex Fourn

Bromus porteri (Coult.) Nash

*Buddleia sessiflora H.B.K.

Buddleia wrightii Robins

*Bumelia persimilis subsp. sessiflora (Hems1.) Cronquist

Bumelia arborescens Rose *Bursera laneifolia (Schlecht») Engl ,,

Bursera fragilis Wats,

*Bursera penicillata (Sesse & Moc. ex DC) Engl»

Bursera inopinata Bulbock

+Caesalpinia caladenia Standi,

Caesalpinia standleyi (Britt. 6c Rose) Stand1 »

*Centaurium exaltatum (Griseb.) Wight=

Erythraea douglasii Gray

*Cercidium floridum Benth»

Cercidium torreyanum (Watse) Sarg»

*Condaliopsis lycioides (Gray) Suesseng

Condalia lycioides (Gray) Weberb.

*Coreocarpus parthenioides Benth. var« parthenioides

Coreocarpus shrevei var. latilobus Sherff.

*Dalea albiflora Gray

Dalea gentry! Standi.

*Dalea cliffortiana Willd.

Dalea nigra Mart. & Gal.

4-Dalea elata Ho 6c A«

Dalea af» flaya Mart. & Gal*

Dalea flava Mart. 6c Gal.

4-Dalea leucostachys DC

Dalea af. mucronata DC*

* + Dalea lumholtzii Rob. & Fern.

Dalea astragalopsis Standi. .

Dalea af. cyanea Greene. +Dalea nutans Wild*

Dalea diffusa Moric (sp. 1913)

■ +Dalea obreniformis (Rydb,) Barneby

Dalea polygonoides Gray

d-Dalea pringlei Gray

Dalea grayi Vail

d-Dalea scandens (Miller) Clausen

Dalea occidentalis (Rydb.) Wiggins

^Datura inoxia Mill»

Datura meteloides D C .

*Dennstaedtia distenta (Kunze) Moore

Dennstaedtia mexicana. Rosenst.

Dicksonia af. rubiginosa Kaulfo

*Descurainia pinnata. subsp. ochroleuca (Wooton) Detling

Sophia ochroleuca Wooton

*Desmodium angustifolium (H»BeKe) var. gramineum (Gray) Schubert

Desmodium gramineum Gray

*Desmodium procumbens (Mill.) Hitch, var. exiguum (Gray) Schubert

Desmodium exiguum Gray *

-Draba cuneifolia Nutt, ex Torr. & Gray var. integrifolia S. Wats.

Draba cuneifolia var. brevifolia Wats.

-Drymaria leptophylla (Cham. & Schl,) Fenzl. ex Rohrb. var. leptophylla

Drymaria tenella Gray

-Drymaria leptophylla (Cham. & Schl.) Fenzl ex Rohrb. var. nodosa (Engelm) JY Duke

Drymaria nodosa Engelm. 265

*Dyssodia porophylla (Cav.) Cav. subsp. cancellata (Cass.) Strother var» cancellata

Dyssodia cancellata (Cass.) Gray

^Elvira biflora (L«) D C »

Delilea biflora (L e) Kuntze

-f-Euphorb ia capitellata Eng elm.

Euphorbia pycnanthema Engelm*

^Euphorbia dentata Michx. var = cuphosperma Engelm.

Euphorbia cuphosperma Boiss

*Gaura mutabilis Cav.

Gaura gentryi Standi.

*Gentianella detonsa (Rottb.) G. Don subsp. superba (Greene)J.M«.Gillett

Gentiana superba Greene

^Geranium mexicanum HoBeKe var. resimum (Small) Moore

Geranium resimum Small»

-fGeranium wislizeni Wats*

Geranium albidum Rydb .

'("Geranium wislizeni Wats.

Geranium geoides Small *

*Gouania rosel Wiggins

Gouania mexicana Rose

-Gratiola brevifolia Raf.

Ilysanthes inaequalis (Walt) Penn

'("Habenaria clypeata Lindl*

Habenaria schaffneri Wats * *Habenaria quinqueseta (Michx«) Swart

Habenaria oreophila Greenm.

^Heliotropium fruticosum L 0

Heliotropium phylostachyum Tprr«

^Heliotropium ^reenmanii Wiggins

Heliotropium mexicanum Green»

*Heliotropium procumbens Mill,

Heliotropium inumdatum Sw.

*Herissantia crlspa (Lo) Brizicky

Abutilon crispum Don

*Hexalectris grandiflora (Rich. & Gal.) L 0

Corallorrhiza grandiflora Rich. & Gal.

Hexalectris mexicana Greenm.

*Holodiscus dumosus (Nutt.) Heller var. dumosus

Holodiscus dumosus (Nutt.) Heller

*Hybanthus attenuatus (Humb. & Bbnpl.) G. K. Schulze

Hybanthus. riparius (H.B.K.) Standi.

^Hymenothrlx palmeri Gray

Hymenopappus palmeri (Gray) 0. Hoffm.

-bindigofera macilenta Standi.

Indigofera laevis Rydb.

*1 pornopsi.s pinnata (Cav.) V. Grant

Gilia pinnata (Cav.) Brand. d-Kuhnia chlorolepis Wooton & Stand ley

Kuhnia rosmarinifolia Vent 267

*Kuhnia oreithales Robinson

Kuhnia ro smar inifoIia Vent

+Lamourouxia viscosa H.BeK,

Lamourouxia coccinea Gray

^Leptochloa filiformis (Lam.) Beauv=

Leptochloa mucronata (Michx.) Kunth

*Loeselia ciliata L .

Loeselia involucrata Don

*Ludwi%ia octovalvis subsp. sessiflora (mich.) Raven

Jussiaea suffruticosa L e

^Lycopersicum esculentum var« cerasiforme (Dun) Gray

Lycopersicum esculentum Mill•

+Machaeranthera.tenuis (Wats.) Turner & Horne

Psilactis asteroides Gray ftMalaxis unifolia Michaux.

Micro.s-tylis ophioglossoides Nutl.

'

Manihot caudata Greenm.

*Manihot rubricaulis Johnston subsp. isoloba (Standi.) Roger & Appan.

Manihot isoloba Standi.

-Matelea caudata (Gray) Woodson

Vincetoxicum caudatum (Gray) Standi.

^Matelea cordifolia (Gray) Woodson

Rothrockia cordifolia Gray 268.

*Matelea pilosa (Benth«) Woodson

Vincetoxicum quercetorum Standi»

*Matelea tristiflora (Standi.) Woodson

Vincetoxicum tristiflorum Standi.

*Mecardonia vandellioides (H.BoK.) Penn.

Pagesia vandellioides (H.B.K.) Penn

Pagesia procumbens Mill

+Me1ampodium appendiculaturn Robins

Melampodium cupulaturn Gray

*Mentha arvensis L. var. villosa (Benth.) Stewart

Mentha canadensis L 0

^Monarda citriodora Cerv. ex Lagasca subsp. austromontana (Splint) Scora

Monarda austromontana Epling

*Monotropa latisquama (Rydb.) Hutt.

Hypopitys latisquama Rydb.

-Muhlenbergia montana (Nutt.) Hitchc.

Muhlenbergia gracilis Trin.

*Notholaena aurea (Poir) Desv.

Notholaena bonariensis (Willd.) C , Chr.

^Odontotrichum decompositum (Gray) Rydb.

Cacalia decomposita Gray

^Odontotrichum globosum (Rob. & Fern.) Rydb.

Cacalia pratensis Standi. dOenothera hartwegii var. toumeyi (Small) Munz

: Oenothera greggii A . Gray ^Oenothera hookeri subsp. hewetii Cockerell

Oenothera hookeri Torr. & Gray

^Oneidium lon^ifo Hu m Lind lev

OncidiuTti cebolleta (Jacq») Sw.

^Parthenium tomentosum DC var„ stramonium (Greene) Rollins

Parthenium stramonium Greene

*Perityle californica Bentho

Perityle plumigera Harv. & Gray

4-Perityle cordifolia Rydbo

Perityle lloydii Rob. & Fern. d-Perityle gentry! A. M e Rowell

Perityle lloydii Rob. & Fern,

4-Perityle microcephala A . Gray

Perityle splanthoides (Schultz-Bip.) Rydb.

*Perityle microglossa Benth.

Perityle emoryi Torr.

4-Peteria pinetorum Poter

Peteria scoparia A. Gray

*Pellaea ovata (Desv.) Weatherby

Pellaea flexuosa (Kaulf,) Link

*Physalis crassifolia Benth. var. crassifolia

Physalis crassifolia Benth.

*Physalis crassifolia Benth. var. versicolor (Rydb.) Waterfall

Physalis sonorensis Standi. 270

*Physalis philadelphica Lamark var„ philadelphica forma philadelphica

Physalis ixocarpa Brot

*Physalis philadelphica Lamark var. philadelphica forma pilosa Waterfall

Physalis pubescens L .

*Physalis viscosa subsp, mollis (Nutto) Waterfall

Physalis mollis Nutt•

*Pionocarpus madrensis (Wats,) Blake

Helianthella madrensis Wats,

*Poly%ala obscura Benth=

.Polygala puberula Gray

*Proboscidea altheaefolia (Benth,) Dec,

Martynia altheaefolia Benth»

*Proboscidea fragans (Lindl,) Dec,

Martynia fragans Lindl,

4-Prosopis glandulosa var. torreyana (L, Benson) Mo C . Johnston

Prosopis afo chilensis (Mol,) Stuntz, i d-Prunus serotina subsp« virens (Woot. & Standi,) McVaugh var, virens

Prunus capuli Cav,

*Prunus serotina subsp, virens (Woot, & Standi.) McVaugh var, virens '

Prunus virens (Woot, & Standi,) Standi,

*Quercus reticulata Humb, & Bonpl,

Quercus diversicolor Trel,

^Ranunculus forreri Greene var. forreri L. Benson

Ranunculus pentadontus Standi,

*Ratibida mexicana (Wats.) Sharp

Lepachys mexicana Wats, -fSaracha procumbens (Cav^) Euiz &

Sara cha jaltomata Schlech-t^

*Sarcostemma elain^nm

FuTia.s-train clausum (Jacq») x

4-Sarcostemrna cynanclioides Beene subsp, hartwe^ll (Vail) le>lm

Fnnastram enmanense (HSehleeht„

^Sarcostemma pannoBmn Beene

- Fnnastram pannosum (Dee.) Sehleeht»

^Schkuhrla pinnata yar» virgata (Llave) Heiser

Schlmhria pringlei Wats»

^Sebastiania pavoniana Mnell* Arg«

Sebastlanla prin%lei Wats4,

*Sela%inella novo1eonensis'Hieron ; , .

SelaKlnella lepidopbylla (Hook» & Grev») Spremg»

*Sela%inella pallescens (Presl) Sprang in Mart

Sela&inella cuspidata Link

*Simsia foetida (Cav») Blake var. decipiens Blake

Simsia amp1exicaul1s Pers » var . decipiens Blake

*Simsia foetida (Cav.) Blake var. foetida

Sims la foetida (Cav») Blake

*Spiranthes aurantiaca (Llave & Lex) Hemsley

Stenorrhynchus aurantiacus Lindl»

*Spiranthes pauciflora Rich & Gale

Sarco^lottis pauciflora (Rich & Galo) Schulte

*Stemmadenia tomentosa var. palmeri (Rose & Standi«,) Woodson

Stemmadenia palmeri Rose & Standi» +Stylosanthes viscosa Swartz

Stylosanthes humilis H.BoK.

v

Tephrosia arcuata (Rydti.) Standio

^Tephrosia nicaraguensis Oerst« ex« Bentho & Oerst»

Tephrosia talpa So Wats o

4-Tephrosia thurberi (Rydb.) Wood

Tephrosia leucantha HoBoKo

^Teucrium cubense Jacq o subsp. depressum (Small) McClintook & Epling

Teucrium depressum Small

"^Thalictrum parvifructum Boivin

Thalictrum fendleri Engelim

4-Thalictrum pinna turn Wats . var , subternatum Boivin

Thalictrum fendleri Englem*

*Thelypteris pilosa (Mart & Gal) Crawford

Dryopteris pilosa (Mart & Gal) C . Chr0

*Thelypteris pilosa var, major (Fourn) Crawford

Dryopteris pilosa var. procurrens (Fee) Co Chr.

*Thelypteris puberula (Baker) Morton

Dryopteris feei C . Chr»

Dryopteris parasitica (L0) Kunze

*Thelypteris rudis (Kunze) Proctor

Dryopteris olygocarpa (Humb. & Bonpl.) Kunze

^Valeriana edulis Nutt. ex Torr. & Gray subsp. edulis

Valeriana lesueurii Standi0 273

^Valeriana sorbifolia H„B0K 0 v a r sorbifolia

Valeriana sorbifolia H 0BoK0

4-Yucca madrensis Gentry

Yucca ri%ida (Engelm.) Trel.

*Zauschneria californica subsp, latifolia (Hooko) Keck

Zauschneria arizonica Davidson

^Zinnia angustifolia H eBeKe

Zinnia linearis Benth,

^Zinnia peruviana■ (L; o) , L 0

Zinnia multiflora L 0 LIST OF REFERENCES

1 o Allen, Caroline K» 1933o A monograph of the American species of * the Genus Halenia. Ann. Mo* Bot* Gard. 20: 119-222,

2 * Allen, Caroline K. 1945, Studies in the Lauraceae VI* Prelimi­ nary Survey of the Mexican and Central American species, Journ, . Arnold Arb. 26: 280-434,

3, Barkley, Fred Alexander. 1937, A Monographic Study of Rhus and its immediate allies in North and Central America, including the West Indies. Ann. Mo. Bot. Card. 24: 265-498.

4 o Benson, Lyman„ 1948. A Treatise on the North American Ranunculi, Amer. Midland Nat. 40: 1-261,

5. Blackwell, Will H,, Jr. 1968. Revision of Bouvardia (Rubiaceae), * Ann. Mo. Bot. Card. 55: 1-30,

6 . Blake, Sidney. 1913. The Genus Simsia. Proc. Amer. Acad. 49: 376-396.

7. Blake, Sidney. 1916. Revision of the Genus Polygala in Mexico, Central America and the West Indies. Contr. Gray Herb. 47: 1-122.

8 . Blake, Sidney. 1918. A Revision of the Genus Viguiera. Contr. Gray Herb. 54: 1-205,

9. Blake, Sidney. 1921. A Revision of the Genus Tithonia. Contr. U, S. Nat. Herb. 20: 423-436.

10. Boivin, Bernard. 1944. American Thalictra and their old World Allies. Contr. Gray Herb. 152: 337-377, 391-445, 453-487.

11. Britton, N, L, 1930. Krameriaceae. North American Flora 23: 195-200.

12. Britton, N. L. and J . N. Rose. 1919-23. The Cactaceae. Carnegie Inst. Wash. Publ. 248.

13. Brizicky, George K. 1968. Herissantia, Bogenhardia and Gayoides (Malvaceae). Jour. Arnold Arb. 59: 278-279.

14. Correll, Donovan S. 1956. Ferns and Fern Allies of Texas. Texas Research Foundation. Renner, Texas. 188 p.

274 275

15. Correll, D. S. and M.'C. Johnston. 1970. Manual of the Vascular Plants of Texas. Texas Research Foundation. Renner, Texas. 1881 p.

16. Cronquist, A. 1945„ Studies in the Sapotaceae. III. Dipholis and Bumelia. Journ. Arnold Arb. 26: 435-471.

17. Crosswhite, Frank S . 1966. Revision of Penstemon Section Chamaelon (Scrophulariaceae). Sida 2: 339-346.

18. Dalla Torre, C. G. de and H. Harms. 1900-07. Genera Siphono- gamarum. Lipsiae. Sumbitus Guilelmi Engelmann. 921 p.

19. Darlington, Josephine. 1934. A Monograph of the Genus Mentzelia. Ann. Mo. Bot. Gard. 21: 103-226.

20o De Candolle, A. 1864. Begoniaceae. Prodomus Systematis Naturalis 15: 309o

21. Duke, James. 1961. Preliminary Revision of the Genus Drymaria. Ann. Mo. Bot. Gard. 48: 173-268.

22. Eastwood, Alice. 1909. Synopsis of the Mexican and Central American species of Castilleia. Proc. Amer. Acad. 44: 563- 591.

23. Eastwood, Alice. 1934. A Revision of Arctostaphylos with key and descriptions. Leaflets of Western Botany I: 105-128.

24. Epling, Carl. 1933. Asterohyptis: a newly proposed Genus of Mexico and Central America. Bull. Torrey Bot. Club 60: 17- 21.

25. Epling, Carl. 1934. Preliminary Revision of American Stachys. Reper. Spec. Nov. 80: 1-75.

26. Epling, Carl. 1942. The American Species of Scutellaria. Univ. Calif. Publ. Bot. 20: 1-146.

27. Ernst, Wallace. 1972. Floral Morphology and Systematics of Lamourouxia (Scrophulariaceae: Rhinanthoideae). Smithsonian Contr. Bot. 6 : 1-63.

28. Everly, Mary Louise. 1947. A Taxonomic Study of the Genus Perityle and related genera. Contr. Dudley Herb. 3: 375-396.

29. Ewan, Joseph. 1945* A Synopsis of the North American Species of Delphinium. Univ. Colo. Studies. Ser. D . Physical and Biol* Sci. 2: 55-244. 276

30e Fosberg, F • R» 1959» Nomenclatural Notes on Datura Lo Taxon 8 : 52-57.

31. Gentry9 H. S« 1942. Rio Mayo Plants. Carnegie Inst. Wash. Publo 527.

32. Gentry, H. S. 1972. The Agave Family in Sonora. U.S.D.A. Publo 339.

33 o Gillett, John M. 1957. A Revision of the North American Species of Gentiane11a Moench. Ann. Mo. Bot. Card. 44: 195-269.

34. Goldberg* Aaron. 1967. The Genus Melochia L. (Sterculiaceae). Contr. IT. S« Nat. Herb. 34: 191-363.

35. Gould, Frank Wo 1951. Grasses of Southwestern United States. University of Arizona Biological Science Bulletin N. 7.

36 . Grant, Adele L. 1924. A Monograph of the Genus Mimulus. Ann. Mo. Bot. Card. 11: 99-388.

37. Grant, Verne. 1956. A Synopsis of Ipomopsis. El Aliso 3: 351- 362.

38. Hagen, Stand ley H. 1941. A Revision of the North American Species of the Genus Ani sac an thus. Ann. Mo * Bot. Card. 28: 385-408.

39. Hall, Harvey M. 1928. The Genus Happloppus. A Phylogenetic Study in the Compositae. Carnegie Inst. Wash. Publ. 389. 391 p.,

40. Heiser, Charles., Jr. 1945. A Revision of the Genus Schkuhria. Ann. Mo. Bot. Card. 32: 265-278.

41. Hevly, Richard H. 1965. Studies of the Sinuous Cloak Fern (Notholaena sinuata) Complex. Journ. Arizona Acad. Sci. 3: 205-208.

42. Hevly, Richard H. 1968. Nomenclatural History and Typification of Martynia. and Proboscidea (Martyniaceae). Taxon 18: 527-534.

43. Hilend, Martha. 1929. A Revision of the Genus Zauschneria. Amer. Journ. Bot. 16: 58-68.

44. Hitchcock, A. S. 1931. The Genus Lasiacis. North American Flora 17: 294-300.

45. Hitchcock, A. S. 1931. The Genus Dpiismenus. North American Flora 17: 307-309. 277

46. Hitchcock. A. S. 1935. The Genus Muhlenbergia. North American Flora 17: 431-476.

47. Hitchcock^ A. S. 1951. Manual of the Grasses of the United States« U. S. Dept. Agric* Misc. Pub. 200. 1051 p.

48 o Hitchcock, Charles L . 1932e A Monographic Study of the Genus Lycium of the Western Hemisphere. Ann. Mo. Bot. Card. 19: 179- 374.

49. Hitchcock, Charles L. 1933. A Taxonomic Study of the Genus Nama I. II. AmerJour. Bot. 20: 415-430, 518-534o

50. Holm, Richard W. 1950. The American Species of Sarcostemma R. Br. (Asclepiadaceae). Ann. Mo. Bot. Card. 37: 477-560.

51. House, Homer Deliver. 1906. Studies in the North American Convolvulaceae, II. The Genus Operculina. Bull. Torrey Bot. Club 33: 495-503.

52. House, Homer Doliver. 1908. The North American Species of the Genus Ipomoea. Ann. N. Y. Acad. Sci. 18: 181-263.

53. House, Homer Deliver. 1908. Studies in the North American Convolvulaceae. IV. The Genus Exogonium. Contr. N 0 Y. Bot. Card. 104: 97-107.

54. . Johnston, Ivan M. 1924. Studies in the Boraginaceae. II. Lithospermum. Contr. Gray Herb. 70: 18-31.

55. Johnston, Ivan M. 1925. The North American Species of Cryptantha. Contr. Gray Herb. 74: 1-114.

56. Johnston, Marshall C . 1962. Revision of Condalia including Microrhamnus (Rhamnaceae). Brittonia 14: 332-368*

57. Johnston, Marshall C. 1962. The North American Mesquites Prosopis Sect. Algaroba (Leguminosae). Brittonia 14: 72-90e

58. Jones, W. Wo 1905. A Revision of the Genus Zexmenia. Contr. Gray Herb. 30: 143-167*

59. Kearney, Thomas P. 1935. The North American Species of Sphaeralcea Sub-genus Eupshaeralcea. Univ. Calif. Publ. Bot. 19: 1-128.

60. Kearney, Thomas P. 1951. The American Genera of Malvaceae. The Amer. Midland Nat. 46: 93-131. 278

61. Kearney, Thomas P. 1955. A Tentative Key to the North American Species, of Abutilon, Millers. Leaflets of Western Botany 7: 241-254.

62. Kearney, Thomas P. 1955. A Tentative Key to the North American Species of Hibiscus, L. Leaflets of Western Botany 7: 274- 284.

63. Kearney, T. H. and Peebles, R. H. 1969. Arizona Flora (2nd Ed. with Suppl. by Howell, J . Thomas and McClintock, Elizabeth) . University of California Press, Berkeley. 1085 p.

64. Keck, David D . 1937. Studies in Penstemon V. The Section Peltanthera. The Amer, Midland Nat. 18: 790-829.

65. Keck, David D; 1946. A Revision of the Artemisia vulgaris Complex in North America. Proc. Calif. Acad. Sci. ser 4, 25: 421-468.

66. Killip, Ellsworth P. 19380 The American Species of Passifloraceae. Field Museum Nat„ Hist., Bot. Ser. 19: 1-613.

67. Knobloch, Irving W. and Donovan S. Correll. 1962. Ferns and Fern Allies of Chihuahua, Mexico« Texas Research Foundation. Renner s Texas. 198 p.

68. Kobuski, Clarence E. 1926. A Revision of the Genus Privao Ann. Mb. Dot. Card. 13: 1-34.

69. Kobuski, Clarence E. 1928* A Monograph of the American Species of the Genus Dyschoriste. Ann. Mo. Bot. Gard. 15: 9-90.

70. Krukoff, B. A. 1939. The American Species of Erythrina. Brittonia 3: 205-337.

71. Lay, Ko K o . 1950. The American Species of Triumfetta L. Ann* Mo. Bot. Gard. 37: 315-395.

72. Lewis, Harlan. 1945. A Revision of the Genus Trichostema. Brittonia 5: 276-303.

73. Ley, Arline. 1943. A Taxonomic Revision of the Genus Holodiscus (Rosaceae). Bull. Torrey Bot. Club 70: 275-288*

74. Lint, Harold and Carl Epling. 1945. A Revision of Agastache. The Amer. Midland Nat. 33: 207-230.

75. Mackenzie, Kenneth K. 1931-35. Cyperaceae. North American Flora 18: 1-478. 279

76.. Mathias, Mildred E. and Lincoln Constance. 1941. A Synopsis of the North American Species of Eryngium. The Amer. Midland Nat. 25: 361-387.

77 - Mathias, Mildred E. and Lincoln Constance. 1944. Umbelliferae. North American Flora 28B: 43-160.

78o McClintock, Elizabeth and Carl Epling. 1946. A Revision of Teucrium in the New World, with observations on.its variation, geographical distribution and history. Brittonia 5: 491-510.

). ■ : ' • 79- McMinn, H. E. 1942. A Systematic Study of the Genus Ceanothus. Ceanothus Santa Barbara Botanic Garden: 131-308.

80. McVaugh, Rogers. 1946. A Key to. the North American Species of Lobelia. The Amer. Midland Nat. 24: 681-702.

81. McVaugh, Rogers. 1951. A Revision of the North American Black . Cherri.es (Prunus serotina Ehrh.«, and Relatives.) Brittonia 7: 279-315.

82. McVaugh, Rogers and Jerzy Rzedowski. 1965. Synopsis of the Genus Bursera L. in western Mexico, with notes on the material of ' Bursera collected by Sesse & Mocino. Kew Bull. Misc. Inf. 18: 317-382.

83. Meyer, F. G. 1951. Valeriana in North America and West Indies (Valerianaceae). Ann. Mo. Bot. Gard. 38: 377-5030

84. Miller, Kim I. and Grady L. Webster. 1967. A Preliminary Revision of Tragia (Euphorbiaceae) in the United States. Rhodora 69: 241-305.

85. Millspaugh, Chas. F. 1913. The Genera Pedilanthus and Cubanthus and other American Euphorbiaceae. Field Mus. Nat. Hist., Bot. Ser. 2: 353-371.

86. Mohlenbrock, Robert H. .1957 • A Revision of the Genus . Stylosanthes. Ann. Mo. Bot. Gard. 44: 299^355.

87. Moore, H. Emery. 1943. A Revision of the Genus Geranium in Mexico and Central America. Contr. Gray Herb. 146: 1-108.

88. Morton, C . V. 1938. Notes on the Genus Saracha. Proc. Biol. Soc. Wash. 51: 75-78.

89. Morton, C. V. 1944. The Genus Hybanthus in Continental North America. Contr. U. S. Nat. Herb. 29: 74-82. 280

90. Morton3 C . V. 1958. Recent Fern Literature. Amer. Fern Jour« 48: 124.

91 © Muller 3 Cornelius H. 1940. A Revision of the Genus Ly copers icon© U© So Dept. Agric. Misc. Publ© N© 382.

92. Munz3 Philip A© 1926. The Antirrhinoideae-Antirrhineae of the New World. Proc. Calif. Acad. Sci. ser. 4. 15: 323-397.

93. Munz3 Philip A. 1931. The North American Species of Orobanche Section Myzorrhiza. Bull. Torrey Bot. Club 57: 611-624.

94. Munz3 Philip A. 1938. Studies in Onagraceae XI© A Revision of the Genus Gaura. Bull. Torrey Bot. Club 65: 105-1223 211-228©

95. Munz3 Philip A. 1949© The Oenothera hookeri Group. : El Aliso 2: 1-47.

96. Munz3 Philip A. 1961. The Lepezia (Onagraceae). Brittonia 13: 73-90.

97. Munz3 Philip A. 1965. Onagraceae. North American Flora Ser = II* Part 5: 1-278.

98. Nash3 George V. 1912 6 The Genus Sorghastrum© North American Flora 17: 128-130.

99. Nashg George V. and Albert S. Hitchcock. 1915© The Genus Panicum. North American Flora 17: 198-288.

100. Norman3 Eliane Meyer. 1966. The Genus Buddieia in North America © Gentes Herb. 10: 47-114.

101. Ockendon, David J . 1965. A Taxonomic Study of Psoralea sub-genus Pediomelum (Leguminosae). The Southwestern Naturalist 10: 81- 124.

102. Ownbey 3 G. B . 1940. A Monograph of the Genus Calochortus. Ann© Mo. Bot. Gard. 27: 371-560©

103. Ownbey3 G. B. 1958. A Monograph of the Genus Argemone for North America and the West Indies. Mem. Torrey Club 21: 1-159©

104© Payne3 Willard W. 1964. A Re-evaluation of the Genus Ambrosia (Compositae). Jour. Arnold Arb. 45: 401-430.

105. Payson3 Edwin Blake. 1918© The North American Species of Aquilegia. Contr. U© S © Nat. Herb. 20: 133-157. 281

106. Fennel, Francis.W. 1919. The Genus Eysenhardtia. North American Flora 24: 34-40.

107. Fennel, Francis W. 1921. Veronica in North and South America. Rhodora 23: 1-22, 29-41.

108. Fennel, Francis W. 1946. Reconsideration of the Bacopa-Herpestis • Froblem of the Scrophulariaceae. Froc. Acad. Nat. Sci. Phil. 98: 83-98.

109. Perry, Lily M. 1929. A tentative Revision of Alchemilla and Lachemilla. Contr. Gray Herb. 84: 1-57.

110. Ferry, Lily M. 1933. A Revision of the North American Species of Verbena. Ann. Mo. Bot. Gard. 20: 239-362.

111. Finkava, Donald J . 1967. Biosystematic Study of Berlandiera (Compositae). Brittonia 19: 285-298.

112. Piper, C. V. 1925. The American Species of Canavalia and Wenderothia. Contr. U. S. Nat. Herb. 20: 555-588.

113. Pippen, Richard W . 1968. Mexican Cacalioid Genera Allied to Senecio (Compositae). Contr. U. S. Nat. Herb. 34: 365-447.

114. Porter, L. C. 1956. The Genus Peteria (Leguminosae). Rhodora 38: 344-354.

115. Powell, A. M. 1965. Taxonomy of Tridax (Compositae). Brittonia 17: 47-96.

116. Powell, A. M. 1973. Taxonomy of Perityle Section Laphamia (Compositae - Helenieae-Peritylinae). Sida 5: 125.

117. Raven, Peter H. 1963. The Old World Species of Ludwigia (including Jussiaea)., with a synopsis of the tienus (Onagraceae) . Reinwardtia 6: 327-427.

118. Rechinger, K. H., Jr. 1937. The North American Species of Rumex. Field Mus. Nat. Hist., Bot. Ser. 17: 1-151.

119. Richard, E. Leon. 1968. A Monograph of the Genus Ratibida. Rhodora 70: 348-393.

120. Robinson, B. L. 1900. The Genus Russelia. Proc. Amer. Acad. 35: 319-321.

121. Robinson, B. L. 1913. A Generic key to the Compositae- . Eupatorieae. Proc. Amer. Acad. 49: 430-437. 282

122 o Robinson, B . L. 1917- A Monograph of the Genus Brickellia, Memo Gray Herb. 1: 1-151.

123. Robinson, B . L. 1930e The Stevias of North America. Contr. Gray Herb. 90: 90-159.

124. Rollins, Reed C. 1950„ The Guayule Rubber Plant and its relatives. Contr. Gray Herb. 172: 3-72.

125. Rose, Jo N. 1903. Synopsis of the Species of Cologania. Contr. Uo S. Nat. Herb. 8: 34-42.

126. Rose, Jo N. 1903. Manfreda and its species. Contr. U 0 S. Nat. Herb. 8:15-23.

127. Rose, Jo N. 1911. Burseraceae. North American Flora 25: 241- 261 o

128. Roush, Eve M. Fling. 1931. A Monograph of the Genus Sidalcea. Ann. Mo. Bot. Gard* 18: 117-244.

129. Rudd, Velva E. 1955. The American Species of Aeschynomene. Contr. Uo S. Nat. Herb. 32: 1-172.

130. Rudd, Velva E. 1956. A Revision of the Genus Nissolia. Contr. U. S. Nat. Herb. 32: 173-206.

131. Rydberg, Per Axel. 1915. The Genus Tagetes. North American Flora 34: 148-159.

132. RydbergPer Axel. 1916. The Genus Pectis . North American Flora 34: 194-216.

133. Schubert, Bernice G. 1940. Desmodium: Preliminary Studies. Contr. Gray Herb. 129: 3-31.

134. Schubert, Bernice G. 1941. Desmodium: Preliminary Studies II. Contr. Gray Herb. 135: 78-113.

135. Scora, Rainer W. 1967. Interspecific Relationships in the Genus Monarda (Labiatae). Univ. Calif. Publ. Bot. 41: 1-59.

136. Senr, Harold A. 1939. The North American Species of Crotalaria. Rhodora 41: 317-367.

137. Sharp, Ward McClintic. 1935. The Genus lostephane. Ann. Mo. Gard. 22: 77-84.

138. Sherff, Earl E. and Edward Johnston. Alexander. 1955. The Genus Bidens. North American Flora II. 2: 130-146. 283

139. Sherff5 Earl E. and Edward'Johnston Alexander. 1955« The Genus Cosmos a North American Flora II. 2: 130-146.

140. Shinners3 Lloyd H. 1946. Revision of the Genus Kuhnia L. Wrightia 1: 122-144.

141. Shreve, Forrest and Ira L . Wiggins. 1964. Vegetation and Flora of the Sonoran Desert. Vol. I, II. Stanford University Press. Stanford, California.

142. Small, J . K. 1895. A. Monograph of the North American Species of * the Genus Polygonum. Bot. Mem. Columbia Univ. It 1-183.

143. Sorensen, Paul D . 1969. Revision of the Genus Dahlia (Compositae • Heliantheae-Coreopsidinae). Rhodora 71: 309-365, 367-416.

144. Sprague, T. A. 1922. A Revision of the Amoreuxia. Kew Bull. Misc. Inf. 1922:97-105.

145. Standley, P 6 C . 1920-26. Trees and Shrubs of Mexico. Contr. U e S e Nat. Herb. 23: 1-1721.

146. Standley, P. C. and collaborators. 1943^73. Flora of Guatemala» Field Mus. Nat. Hist., Bot. Ser. 24, parts 1-9.

147. Stewart, Sara R. 1944* Mentha arvensis and some of its North American variations. Rhodora 46: 331-335.

148. Straw, Richard M= 1963. The Penstemons of Mexico. Ill. Two Subsections in the Section Fasciculus. Brittonia 15: 49-64.

149. Strother, John L. 1969. Systematics of Dyssodia cavanilles (Compositae:Tageteae). Univ. Calif. Publ. Bot. 48: 1-88.

150. Torres, Andrew M. 1963. Taxonomy of Zinnia; Brittonia 15: 1-25.

151. Trelease, William. 1916. The Genus Phoradendron„ a Monographic Revision. Univ. Illinois Bull. 13: 1-224.

152. Trelease, William. 1924. The American Oaks. Mem. Nat. Acad. Sci. 20: 1-205.

153. Tryon, Rolla. 1956. A Revision of the American Species of Notholaena. Contr. Gray Herb. 179: 1-106.

154. Tryon, Rolla. 1960. A Review of the Genus Dennstaedtia in America. Contr. Gray Herb. 187: 23-52. 284

155. Turner, B. L. 1962. Taxonomy of Hymenothrix (Helenieae, Com Compositae). Brittonia 14: 101-120.

156. Turner, B. L. and David Horne. 1964. Taxonomy of Machaeranthera Sect. Psilactis (Compositae, Astereae). Brittonia 16: 316-331.

157. Voss, John W. 1937. A Revision of the Phacelia crenulata group for North America. Bull. Torrey Bot. Club 64: 81-144.

158. Waterfall, V. T. 1967, Physalis in Mexico, Central America and the West Indies. Rhodora 69: 82-120, 203-239, 319-328.

159. Watson, E. E. 1923. The Genus Heliocarpus. Bull. Torrey Bot. Club 50: 109-128.

160. Webster, Grady L. 1967. The Genera of Euphorbiaceae in the Southeastern United States. Jour. Arnold Arb. 48: 303-361, 363-430.

161. Webster, Grady L. 1970. A Revision of Phyllanthus . (Euphorbiaceae) in the Continental United States. Brittonia 22: 44-76.

162. Wiggins, Ira L. 1939. Distributional Notes on and a Key to the Species of Cheilanthes in the Sonoran Desert and Certain Adjacent Regions. Amer. Fern Jour. 29: 59-69.

163. Wiggins, Ira L. 1942. Acacia angustissima (Mill) Kuntze and its near relatives. Contr. Dudley Herb. 3: 227-239.

164. Williams, Louis 0. 1951. The Orchidaceae of Mexico. Ceiba 2: 1-321.

165. Wilson, Percy. 1932. The Genus Talinum. North American Flora 21: 280-289.

166. Wolf, Carl B. 1938. The North American Species of Rhamnus. Monog. Rancho Santa Ana Bot. Gard., Bot. Ser. 1:1-136.

167. Wood, Carrol E. 1949. The American Barbistyled Species of T^phrosia (Leguminosae). Contr. Gray Herb. 170: 193-231, 233-302, 305-364, 369-384.

168. Wood, Carrol E. 1961. The Genera of Ericaceae in the South­ eastern United States. Jour. Arnold Arb. 42: 10-80.

169. Woodson, Robert E., Jr. 1928. Studies in Apocyttaceae. II. A Revision of the Genus Stemmadenia. Ann. Mo. Bot. Gard. 15: 341-378. 285

170. Woodson, Robert E ., Jr. 1933. Studies in Apocynaceae. IV. The American Genera of Echitoideae. Ann. Mo. Bot. Card. 15: 341- 378.

171. Woodson, Robert E ., Jr. 1938. Studies in Apocynaceae. VII. An evaluation of the Genera Plumeria L . and Himatanthus Willd. Ann. Mo. Bot. Card. 25: 189-224.

172. Woodson, Robert E ., Jr. 1941. The North American Asclepiadaceae. I. Perspective of the Genera. Ann. Mo. Bot. Card. 28: 193- 244.

173. Woodson, Robert E., Jr. 1954. The North American Species of Asclepias L. Ann. Mo. Bot. Card. 41: 1-211.

174. Yuncher, Truman George. The Genus Cuscuta. Mem. Torrey Bot. Club 18: 113-331.