A Vegetative Key to the Grasses of Erath County

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A VEGETATIVE KEY TO THE GRASSES

OF ERATH COUNTY, TEXAS

THESIS

Presented to the Graduate Council of the

North Texas State College in Partial

Fulfillment of the Requirements

For the Degree of

MASTER OF SCIENCE

By 193392 Inez Evans Robins on, B. S.

Dublin, Texas

August, 1951 193392

TABLE OF CONTETS Page

INTRODUCTION ...... a . . 0 0 . . . . . 1

M ETHODS...... a " . . . 0 . . . . 5

USE OF THE KEY ...... a . 0 . . 0 S 0 . 7

Mechanics Glossary

KEY TO GJERA AND SPECIES. .0 . 0 . 0 . 0 . . 12

CONCLUSIONS...... 0 0 " . 0 0 . 0 0 0 . 24

LITERATURE CITED ...... 0 * * 0 0 . . 0 . 0 . 25

APPENDIX ...... 0 . 0 0 0 0 . 0 0 . 26

Index of Scientific Names Cross Index of Common Names Index of Plates

iii A VEGETATIVE KEY TO THE GRASSES

OF ERATH COUNTY, TEXAS

INTRODUCTION

At the present time, in contrast to an earlier agricul-

tural period, stock farming and ranching are of primary eco- nomic importance in Erath County, Texas * The rough stony

land with thin soils, which are described later in this chapter, are best fitted for grazing. With this natural condition pre-

vailing in the county and with considerable areas of deep pro-

ductive soil to supplement the grazing possibilities, farmers have turned from row crops to ranching and dairying.

Because of this change in agricultural practices, many

individuals of the county have evidenced an interest in native

grasses and their identification. This study is a result of

such an interest.

Two extensive studies, including keys, have- been made by authorities of the grasses of Texas (Hitchcock 1935; Silveus

1933). In these floras identifications are based on floral morphology and not on vegetative characteristics. Descrip-

tions, ranges, and habitats of indigenous species are extensive and need no further amplification in this treatise. However, since the phenology of grasses is seasonal, sometimes

not occuring until the second year as in biennials, it is not

1 2

always possible to collect a specimen with a fully developed infloresence. Hence, a key based on vegetative characters makes identification possible for grasses in all stages of growth. To meet such a need this key was prepared for the grasses of West Central Texas . As previously mentioned, the study area for this investi- gation was limited to Erath County, which is included in an agricultural area with approximately two-thirds of its 693,120 acres in native grass pastures (Bushnell 1923). A majority of the same grasses are found in the adjoining counties of

Comanche, Eastland, Hood, and Sommerville. Their floristic unity is evident from the distributional sequences of Cory

(Cory and Parks 1937) in that the completed list of collected grasses includes most of the grasses of the west section of his plant areas 4 and 7. Erath County is located in the western section of plant area 4 and joins area 7.

Erath County is situated slightly north of the center of

Texas and about 80 miles southwest of Dallas (Fig. 1). The coordinates of the county are 980 17t W. longitude and 320 10t

N. latitude. The enclosed land mass is irregular, is about

40 miles long by 30 miles wide, and has an area of approximately 1,083 square miles (Bushnell 1933), (Fig. 2). The eastern section of Erath County is a part of the

Grand Prairie. This association is characterized by a discon- tinuous mosaic of small clumps of liveoaks and associated species grading into a mesquite tree and scattered scrub 3

savannah in the southern part. The western portion is a part

of the West Cross Timbers. Structurally, the forest is dom-

inated by postoak and blackjack oak to a lesser degree. In

the prairies coarse grasses predominate with grama grasses

and short grasses in the lower synusiae. In the southern area

mesquite comes in as a ruderal subseral invader (Carter 1931).

The county has a climate characteristic of the grasslands

formation, even though forest communities exist because of

secondary edaphic control. That is, the average annual rain-

fall, determined by the records of the United States Weather

Bureau at Dublin, Texas, is 29.38 inches and the mean annual

temperature is 64.60 F. The growing season consists of 239 days.

Physiographically, the southern two- thirds of the county

consists of a smooth southwardly sloping plain, with a few

flat-topped hills in the southeastern part of the county.

This smooth plain is bordered on its northern edge by a nar-

row belt of hilly country formed by a series of narrow valleys

and terminated by an abrupt drop to a lower plain. The rough

belt including the abrupt drop is about three miles wide and

runs east and west across the northern part of the county,

turning southward along the eastern margin for several miles.

North of this rough belt is a parallel, smooth lowland strip

three to five miles wide, which gradually rises northward and merges into a low hilly area occupying the extreme northern part of the county (Bushnell 1923). 4

The elevations in the central part of the county range from 1,200 feet to 1,500 feet. The maximum altitude for the county is over 1,750 feet and the average elevation is 1,466 feet.

The soils of the county include the six soil series:

San Saba, Denton, Crawford, Brackett, Bell, and Lewisville of the Grand Prairies region and Windthrost, Nimrod, and

Milam of the Western Cross Timber region. The San Saba soils are black or dark brown in color with very dark-gray clay subsoils. These soils have the deepest profile. The Denton and Crawford soils are shallower and the Brackett soils are very thin. The soils of the Windthrost and Nimrod series are sandy, being very deep in some areas and thin in others. These top soils contain little organic matter and are lighter in texture than the subsoils (Carter 1931). METHODS

The orientation of this study began with a collection of the grasses of Erath County during their flowering periods.

Collections were made in the. spring and fall of 1950 and 1951 to obtain both vernal and autumnal grasses. Identifications were made from the grass floras previously mentioned (Hitch-

cock 1935; Silveus 1933) and checked against specimens in the herbarium of North Texas State College for verification. In addition, the list was checked by W* A. Turney, Conservationist,

United States Department of Agriculture of Dublin, Texas. Fi-

nally, the list was compared with that prepared by W. M. Cory for the plant areas of which Erath County is a part (Cory and Parks 1937).

On the basis of the above inder fications, a critical

study of the vegetative characteristics was made and a key

based on these features prepared. The width of the blade and

characteristics of the ligule, roots, culms, and sheaths were used to distinguish each of the eighty-six specimens found in

the collection area. A drawing was made of the longitudinal section of the

juncture of the blade and the sheath of each grass. This diag- nostic section includes the collar, ligule, a part of the blade

and sheath, and auricles, if present.

5 6

A glossary of special terms was prepared from the descriptions made in the key to facilitate its use. And in addition an index was made of the scientific designations together with a cross index of common names recognized by Hitchcock, Silveus, and Cory. USE OF THE KEY

Mechanics

The key prepared is of a dichotomus nature, The pairs of contrasting characters lead one to an ultimate decision of the entity in that only one of the two designations is correct.

For example, if a collected plant is either grass or grass- like, as might be the case of a sedge or rush, a determination is made first from Oa and Ob. If it is found from Oa that the plant is a grass one proceeds, then, to la and lb, a pair of- characters which separates all grasses into annuals and peren- nials. If it is the former, one proceeds to 2a and 2b. Next, pubescence of the leaf and sheath must be determined. Should one find both parts pubescent one follows through to number 13 and investigates the culm node, and if glabrous, continues to number 14a. Then if the ligule is ciliate and the blades

7-16mm. wide, the plant is Panicum texanum. Otherwise 14b, with ligule membranaceous and entire, and blades 2-7mm. wide, would identify the grass as Chloris vata. A further check

may be made by comparing the specimen with the drawings of the

two above species, either Fig. 25 or Fig. 26 of Plate VI.

Glossary

The glossary of terms which follows will aid in the use

of the descriptions found in the key. Acuminate--graduAlly tapering to a sharp point, more tapered than acute (Fig. 13). 7 8

Acute--tapered rather evenly to a point.

Annual--living but one year. Annual grasses have neither dead culms nor leaves of the previous year's growth at the base.

Antrorse--directed upward and forward. Opposed to retrorse.

Apex--tip of the blade, sheath, ligule, or culm.

Appressed--lying against an organ or part.

Aristate--awned, provided with a bristle at the end. Attentuate--tapering into a long slender point.

Auricle--having ear-like appendages or projections at the

juncture of the base of the blade and the sheath.

Blade--the expanded part of the leaf above the sheath.

Bulbous--enlarged and fleshy, bulb-like in shape or structure

(Fig. 4).

Canescent--gray-pubescent or hairy.

Cartilaginous--gristly, hard and tough but elastic.

Ciliate--fringed with hairs on the margin (Fig. 7).

Collar--the region on the outside of the grass leaf which

marks the juncture of sheath and blade (Fig. 10b).

Conduplicate--folded together lengthwise with upper surface

within.

Coriaceous--leathery in texture.

Culm--the stem of the grass; often restricted to the true

stem above the ground and to distinguish it from rhizomes and stolons which are modified stems (Fig. 3). Decumbent--more or less reclining or spreading along the

ground. 9

Decurrent--extending down an organ below the insertion; especially used concerning ligules decurrent on the margins

of the sheath.

Depauperate--reduced or undeveloped, plants below the average size.

Erose--irregular notched at apex as if gnawed (Figs. 7 and 8).

Finbricate--fringed, the hairs longer or coarser than the

ciliate condition, finer than laciniate.

Flexuous--bending in opposite directions.

Glabrous--devoid of hairs; smooth in the sense of absence of all hairiness.

Glaucous--covered with a waxy coating that gives a blue-green

color as in the leaf of a cabbage. Hirsute--With short, straight, fairly stiff hairs.

Hispid--bristly; beset with stiff, rough, bristle-like hairs.

Hispidulous--minutely hispid.

Imbricate--overlapping.

Internode--the part of a stem between two successive nodes.

Involute--inrolled, that is, with both edges rolled in toward

the center, as a grass blade, each edge presenting a spiral

appearance in cross section (Fig. 10b).

Keel--projecting ridge on a surface as the keel of a boat (Fig. 9).

Knotted--with enlargements along the root stock.

Lacerate--irregular, as though frayed out by being cut or torn.

Lanate--covered with soft tangled long hairs. 10

Lanceolate--rather narrow tapering to both ends, the broadest part below the middle; lance shaped.

Lanciniate--narrowly incised or slashed.

Ligule--the thin appendage on the side of a leaf at the junc-

tion of sheath and blade (Figs. 3, 6, 13, and 15). Membranous --membrane-like.

Mm.--millimeter; about 1/25 of an inch.

Navicular--boat shaped; shaped like the bow of a canoe.

Nerve--the vascular veins of the blades, glumes, and lemmas

approximately parallel.

Node--the joint of the culm; swollen and joint-like portion

of the stem (Fig. 3).

Ovate--egg-shaped in longitudinal section, broadest below the middle.

Papillose--bearing minute nkpple-shaped projections.

Papillose-hispid--bearing hairs with bases that are slightly

swollen and somewhat nipple-shaped.

Perennial--lasting more than one year; applied to grasses in

which the underground parts last more than one year; and

to woody culms to distinguish them from those which die to

the ground even though the undergrounds are perennial.

Pilose--pubescent with soft, straight hairs. Puberulent--with very short, soft hairs.

Pubescent--in a general sense, and as used here, with hairs. Pustulate--blistery, furnished with pustules or irregular raised pimples. 11

Retrose--turned backward or downward.

Revolute--rolled back from margin of the apex.

Rhizome--an underground stem; rootstock; recognizable by

the scale-like leaves at regular intervals (Fig. 4).

Rigid--stiff and firm.

Rootstock--rhizomes (Fig. 4).

Scabrous--rough to the touch, like sandpaper, due to scale-

like projections from the surface.

Scaly--wi th minute scales on the surface.

Scarious--thin, dry, membranaceous, not green.

Sericeous--velvety.

Setaceous--bristle-like.

Sheath--the lower part of a leaf which usually enfolds the stem (Figs. 3, 15, and 16).

Stolon--a trailing or reclining stem, above ground, which

strikes roots where the joints touch the ground, there send-

ing up new shoots and new plants (Fig. 11).

Striate--marked with slender, longitudinal grooves; minutely

channeled.

Sulcate--grooved longitudinally.

Truncate--square tipped, as though chopped off.

Villous--with long, soft hairs. IEY TO GENERAL AND SPECIES

a, "tens (Gulms, see Fig. 1) hollow, sometimes solid; cylindrical, flattened, not triangular; nodes

conspicuous; leaves two-ranked ...... (1)

Ob. Stems, leaves, and nodes not as above. . . .

grass-like plants. . . . st;op $edges, 0 rushes, and other la. Plants annual. 2) lb. Plants perennial ...... a5)

2a. Blades and sheaths pubescent ...... (2L3)

2b. Blades and sheaths glabrous...... (3)

2c. Either blades or sheaths glabrous...... (6)

3a. Blades navicular . . . . . Poa annua (Fig. 17)

3b. Blades not as above...... (4) 4a. Ligule membranaceous, margins fringed Chloris verticillata (Fig. 18)

4b. Ligule membranaceous, margins entire . . . . (5)

5a. Ligule very thin 4mm. long ...... Phalaris canariensis (Fig. 19)

5b. Ligule very short 0.6mm. long, somewhat erose-ciliate sometimess lower sheath pubescent)

Pestuca octoflora (Fig. 20)

6a,. Blades glabrous; sheathS pubescent (at least lower sheaths as in Horde-2 pusillum sometimes glabrous

as in Eleusine indica) ...... (7) 12 13

6b. Blades pubescent; sheaths glabrous ...... (11)

7a . LoWer sheaths pubescent; upper sheaths scabrous. Hordeum pusillum (Fig. 21)

7b. Lower sheaths glabrous,; upper sheaths pubescent,

papillose at margins ...... Eleusine indica (Fig. 22)

7c. Lower and upper sheaths pubescent...... (8)

8a. Blades 5-10m. wide; sometimes 15mm. wide. . Setariafviridis (Fig. 23)

8b. Blades 6mm. wide or less ...... (9)

9a. Blades 2mm. wide or less. Eragrostis piosa (Fig. 24)

9b. Blades 2-6mm. wide ...... (10)

10a. Ligule membranaceous, fringed . Limnodea arkansana (Fig. 25)

10b. Ligule a ring of hairs .

Eragrostis cilianensis (Fig. 26) h1a. Culms decumbent, flattened; ligules ciliate.

(upper sheaths pubescent on margin) Cenchrus echinatus (Fig. 27)

11b. Culms erect...... (12)

12a. Blades 1-2mm. wide; nodes slender...... Aristida oliganth (Fig. 28)

12b. Blades 2-7mm. wide; nodes swollen...... Bromus secalinus (Fig. 29)

13a. Nodes glabrous ...... (14)

13b. Nodes pubescent...... (15)

-1 -4- 14

14a. Ligule ciliate; blades 7-6mn. wide ...... Panicum texanum (Fig. 30)

14b. Ligule membranaceous, entire blades 2-7Im, wide Chloris virgata (Fig. 31)

I5a. Ligule a ring of hairs...... (16)

15b. Ligule membranaceous or partly so ...... (is)

16a. Blades more than 4mm. wide,...... Panicum fasciculatum (Fig. 32)

16b. Blades less than 4mm. wide...... (17)

17a. Blades roAgh ciliate towards base sometimes

papillose-ciliate ......

Triplasis purpurea (Fig. 33) 17b. Blades glabrous or sparingly pilose

Eragrostis cafllaris QFig. 34)

18a. Ligule barely pubescent ......

porbolus neglectus (Fig. 35)

18b. Ligule entirely glabrous...... (19)

19a. Nodes sparsely pilose, hairs retrose. . . . . Bromus mollis (Fig. 36)

19b. Nodes distinctly pubescent...... * . . (20)

20a . Sheaths as long as or longer than the internode . (21)

20b. Sheaths shorter than the internode...... (22)

21a. Ligule ciliate......

Pauicuo capillare (Fig. 37)

21b. Ligule toothed or erose ...... Bromus secalinus (Fig. 29) 15

22a. heaths green ...... (23)

22b. Sheaths canescent, sericeous......

Bromus aponicus (Fig. 36)

23a. Sheaths open...... * . * .

Digtaria sa nL (Fig. 38)

23b. Sheaths closed...... (24)

24a. Sheaths usually retorsely pilose; sheaths and

blades strongly nerved......

Bromus comutatus (Fig. 36)

24b. Sheaths and blades not as above ......

Bromus catharticus (Fig. 39)

25a. Stolons present ...... (26)

25b. Stolons absent...... (29)

26a. 'tolons 7ith swollen nodes......

Panicum obtusum (Fig. 40)

26b. Stolons with slender nodes...... (27)

27a. Leaves rigid......

modon dacylon (Fig. 41)

27b. Leaves curly...... (28)

28a. Nodes glabrous; internodes short......

Buchloe dactyloides (Fig. 42)

28b. Nodes villous ......

Hilaria Belangeri (Fig. 43)

29a. Rhizomes present...... (30)

29b. Rhizomes absent ...... (45)

30a. Rootstock scales well developed ...... (31) 16

30b. Rootstock scales depauperate ...... (33)

31a. Sheath hairs papillose...... (32)

31b. Sheath hairs neither pustilose nor papillose.

Panicum virgtum (Fig. 44)

32a. Ligule very short, ciliate-fringed......

Bouteloua curtipendula (Fig. 45)

32b. Ligule a ring of short fine hairs . . . . .

Boutelous uniflora (Fig. 46)

33a. Rootstocks long and creeping...... (34)

33b. Rootstocks short...... (36)

34a. Lower section of culm and rootstock canescent or

pale; auricles present......

Agropyron Smithii (Fig. 47)

34b. Culm and rootstock not canescent...... (35)

35a. Ligule membranaceous, about 1mm. long, ovate;

leaf tip navicular......

Poa arachnifera (Fig. 48) 35b. Ligule 3-4mm. long, villous just back of ligule

Andropogon Hallii (Fig. 49)

35c. Ligule membranaceous, ciliate, 2-3mm. long.

Sohum alepense (Fig. 50)

36a. Sheaths longer than the internode ...... (37)

36b. Sheaths shorter than the internode...... (38)

37a. Leaves involute toward apex ...... Panicum Reverchoni (Fig. 51) 17

37b. Leaves flat at apex ...... * * * * Uniola la(Fig. 52) at 38a. Rhizome narrow; internodes long; barbed

nodes, otherwise glabrous ...... Leersia oryzoides (Fig. 53)

(9) 38b. Rhizome stout ...... *. glaucous. 39a . Culms glaucous or purplish; sheaths Andrpgon Drovincialis (Fig. 54) nor purplish . (40) 39b. Culms and sheaths neither glaucous

...... (41) 40a. Rootstock knotted ......

. . . (42) 40b. Rootstock not knotted ...... midribs large. 41a *Nodes swollen, usually dark; blade Paspalum dilatatum (Fig. 55) glabrous. 41b. Sheaths imbricate; sheath and blade Melica mutica (Fig. 56)

(43) 42a. Ligule membranaceous, short ......

. (44) 42b. Ligule 2-5mra. long...... - . . . . .

43a. Blades lanceolate tapering to the end; ligule truncate fringed with short hairs . . . . . Uniola latifolia (Fig. 57)

43b. Blades involute; ligule membranaceous * . . . Manisuris cylindrica (Fig. 58)

. . 44a. Ligule ciliate...... Soru h4haLepnse (Fig. 50)

. . . a 44b. Ligule lacerate ...... + * . * . A2ros2tis alba (Fig. 59) 18

45a. Blades and sheaths pubescent...... (61)

45b. Blades and sheaths glabrous ...... (53)

45c. Either blades or sheaths pubescent...... (46)

46a. Sheaths glabrous; blades with few scattered

long hairs......

Erajrostis sessilisica (Fig. 60)

46b. Blades glabrous; sheaths pubescent...... (47)

47a, Sheaths longer than internodes ...... (48)

47b. Sheaths, at least lower, shorter than internodes. (50)

48a. Culm base bulbous; ligule a ring of short hairs

E raostis curtipedicellata (Fig.61)

48b. Culm base not bulbous; ligule minutely ciliate,

not over 0.5mm. long...... (49)

49a. Blades involute, curved, or flexuous; sheaths

sparsely villous at throat......

Aristida glauca (Fig. 62)

49b. Blades involute drying flat; sheaths rough,

villous at throat . . . .

Aristida purpurea (Fig. 63)

50a. Ligule a ring of short hairs...... (51)

50b. Ligule membranaceous...... (52)

Sla. Upper sheaths longer than internodes inclosing

base of panicle; blades accuminate, margin

long ciliate. ... .s (Fg.

Sporobolus cryptandrus (Fig. 64) 19

51b. Blades flat soon becoming involute to apex with . . long narrow tip; tuf ts of hair at throat. Erarostis secundiflora (Fig. 65)

52a. Ligule short membranaceous, truncate; blades

6-8m . wide flat, auricled......

JElymus irginicus (Fig. 66) cilia 52b. Ligule very short membranaceous, ciliate, 3-6mm. long; blades 2-5mm. wide, long attentuate

Chloris Ea yana (Fig . 67 )

53a* Tip of plant turning scythe-shaped to ground;

. . . ligule decurrent down margins . . . . Schedonnardus paniculatus (Fig. 68)

. . . . (54) 53b. Not as above...... - . . . (55) 54a. Sheaths, as long as, or longer than internodes.

. . . (57) 54b. Sheaths shorter than internodes ......

. . . * (56) 55a. Blades 6-8mm. wide, flat......

55b. Blades 2mm. wide or less; ligules membranaceous,

4-6mm. long, fragile*...... - *. . . Muhlenbr Reverchoni (Fig. 69)

56a. Collar auriculate ...... Lolium multiflorum (Vig. 70)

. . . . 56b. Collar continuous; ligule truncate. . E u canadensis (Fig. 71)

...... 57a. Ligule a dense ring of hairs. . . T~rdia calbesens (Fig. 72) 57b. Ligule membranaceous or wanting ...... (58)

58a. Sheaths striate; ligule very short with a few

cilia . .0...... * * - Bouteloua gracilis (Fig. 73)

58b. Sheaths non-striate...... (59)

59a. Blades aristate ......

Chloris cucullata (Fig. 74)

59b. Blades not aristate ...... * (60)

60a. Ligule 3-4mm. long. . . . Qryzopsis hymenoides (Fig;. 75)

60b. Ligule 1-2mr. long...... Andro2poon saccharoides (Fig. 76)

61a. Culm with dark (contrasting) nodes. . . . . Bouteloua rigIdiseta (Fig. 78)

61b. Culm nodes of same coloration as internode (mostly

light color except in Paspalum ciliatfolium and Framrostis lugens where node and internode are

dark...... - - - - - . - - - - * (62)

62a. Sheaths, as long as, or longer than internodes. . (63)

62b. Sheaths, at least upper, shorter than internode . (69)

63a. Sheath nerves prominent; blades rounded and

ciliate at base, acuminate ......

Panicum Scribnerianum (Fig. 79).

63b. Sheaths nerves not prominent...... (64)

64a. Ligule merbranaceous, long, fringed at apex . Trichachne californica (Fig. 80) 64b. Ligules less than 4mm. long or a ring of hairs. . (65)

65a. Ligule a ring of hairs...... (66)

65b. Ligule membranaceous, at least partly so. . . . . (68)

66a. Blades 2mm. wide or less involute, setaceous. Sporobolus heterolepsis (Fig. 81)

66b. Blades expanded, setaceous...... (67)

67a. Ligule 2-4mm. long; blades not attentuate . Eragrostis pectabilis (Fig. 82)

67b. Ligule of short hairs; blades attentuate. .

Eragotis trichodes (Fig. 83)

68a. Blades 7mm. wide; ligule membranaceous, truncate,

fimbriate ...... - *****

l1 dropogon glomeratus (Fig. 84)

68b. Blades 2-6mm. wide, glaucous; ligule about 1.5mm. long, a short membrane with hairs at least 1mm.

long., Panicum Hallii (Fig. 85)

69a. Blades strongly ciliate along a cartilagenous

margin, ligule commonly produced into an auricle Paspalum ciliatifolium (Fig. 86)

69b. Blades with ligule not as above ...... (70)

70a. Sheath striate...... a * Eriochloa sericea (Fig. 87)

70b Sheaths not striate ...... (71)

71a. Ligule 2-4mm. long, thick and stiff; blades

flat above, conduplicate below...... Soraghastr. nuans (Fig. 88)

71b. Ligule thin; blades flat below...... (72)

72a. Ligule a short dense ring of hairs...... (73)

72b. Ligule membranaceous...... (76)

73a. Ligule hairs varying in length; nodes and inter-

nodes tinged with purple...... Eragrostis lumens (Fig. 89)

73b. Ligule hairs uniform in length...... (74)

74a. Blades scabrous on margins...... Triodia flava (Fig. 90)

74b, Blades not scabrous on margins, ...... (75)

75a. Culms striate; blades sparsely papillose-hispid

on margin ......

Bouteloua hirsuta (Fig. 91)

75b. Culms not striate; blades smooth along the margins,

with few hairs on upper surface near the base Eragrostis Beyrichii (Fig. 92)

76a. Ligule densely ciliate-villous; ciliate on margin.

Setaria macrostachya (Fig. 93)

76b. Ligule short ciliate or glabrous...... (77)

77a. Ligule 2-4mm. long; truncate...... Andropogon perf oratus (Fig. 94)

77b. Ligule less than 2mm. long...... (78)

78a. Ligule rounded, short ciliate ......

AndropogZ~on inicus (Fig. 95)

78b. Ligule tot rounded...... (79) 23

79a. Ligule truncate ...... (80)

79b. Ligule of membranaceous lines, minutely ciliate Sporobolus pilosus(Fig. 96)

porobolus asp er(Fig. 96)

80a. Culms solid ...... * . . . . . (81)

80b. Culms hollow...... (82)

Sla. Culms green or purplish; rarely glaucous; sheaths

flattened, rare conspicuously villous . . .

Andropogon sparius (Fig. 97)

81b. Culms glaucous; blades becoming revolute; sheaths

villous......

Andropogn t2rnarius (Fig. 98)

82a. Blades scabrous, white and often repand; culms

lanate at base......

LUtoloma cogntum (Fig. 99)

82b. Culm nodes pubescent; blades scabrous on upper

surface, hispidulous underneath ......

Stpa leucotricha (Fig. 100) CONCLUSIONS

The purpose of this paper was to prepare a simplified key based on vegetative characteristics, by which the grasses of Erath County, Texas, might be identified. It was found that no such key was available and it was evident that due to the seasonal florescence of grasses, a key based on floral morphology was not sufficient.

The results of the study show that there are at least eighty-six grasses native to Erath County. In addition, these grasses are generally prevalent in the area including the sur- rounding counties.

Vegetative taxa are distinctive and their systematic mechanics delineate in such a manner that any typical entity may be easily identified from the others. Such taxa include the point of blade and sheath divergence, ligule variation, width of the blade, characteristics of the root system, and the nature of the culms, and were used to distinguish the species.

While this study includes only a small area, it is evident that similar keys could be prepared for other regions and groups of angiospernts.

24 LITERATURE CITED

Bushnell, T. M., Soil Survey of Texas, Washington, Govern- ment Printin7ffice, l973J. Carter, W. J., Soils of Texas, Bulletin No. 431, Texas Agri- cultural Experiment-tation, 1931.

Cory, V. L., and Parks, H. B., Catalg e of' the Flora of the State of Texas, Bulletin No. 550, Gl lege Station, Texas.,T andM College, 1937.

Hitchcock, A. S., Manual of' the Grasses of' the United States, Washington, Government Printing Office, 1935.

Hitchcock, C. Leo, A Key to the Grasses of Montana, St. Lotis, John S. Swift Company, fl36.

Silveus, W. A., Texas Grasses, San Antonio, Texas, The Clegg Company, 1933.

Tharp, Benjamin C a.,the Vegtation of Texas, Houston, The Anson Jones Press, 1939.

25 APPENDIX

INDEX OF SCIENTIFIC NA'iES

Scientific Name Common Name Key No. Fig. No.

Agropron

Smithii. . . . . Western wheatgrass. . 34a. . 47 Agros tis

alba . . . . . Red top . . . . . 44a. . 59 Andropogon

.0 84 elomeratus . * . . Bushy beard-grass . 68a. .

Hallii . . . . . Hall 's beard-grass. * 35b. 48

perforatus. . 77a. . . 94

lrovincialis . . . Big bluestem. . . * 39a. . " 54 saccharoides 0 . 60b. * . 76

.Silverbeard-grass. sco ius.. , . . Little bluestem . 81a. * . 97 ternarius.. . . . Slivery beard-grass . 81b. . . 98

virginicus. . . . Broom sedge . . . . . 78a. . . 95

Aristida

glauca . * . . Reverchon three-awn 49a. * . 62

. 0 28 oligantha.. . . . Few-flowered aristida 12a.

purpurea. . . . Purple needle grass . 49b. " . 63 Bouteloua 45 curtipendula * . . Side-oats grama , . 32a. .. 0

* . . Blue grama. . . 0 . . . 58a.* . . 73 27

Scientific Name Common Name Key No. Fig. No.

hirsuta. . . ..Hairy grama . . . . 75a " . . 91

r igiLdi s eta . . . Texas grama . . . . 61a . . . 78

uniflora * . Mesquite grass. . . . . 32b . S. 46

Bromus

catharticus. * . Rescue grass. . . . . 24b . . . 38

comautatus . . . Hairy chess . . * . 24a " " " 38

jaonicus.. . . Japanese chess. . . . . 22b . . . 38

mollis . . .Soft chess. .. " . " . 19a 38

secalinus,.. . . chess ...... 12b . . 29

Buchloe

dactyloides.. * . Buffalo grass . " . 28a 42 oenchrus

echinatus. . . Southern sandbar. " . ila 27 Chloris

cucullata...... * " . 59a 74

gaysna . . . . Rhodes grass. . . . 52b 67

verticillata . . Windmill grass. . . .* 4a. . . 18

virta... . . Feather fingergrass 14b .-.

yndon 27a . dactylon .. . .Bermuda grass . . 41 Diitaria 39 sanuinal. Crab grass. . 23a *9 . Echinochloa

Crusgalli.. Barnyard grass. 60c . * . 79 No. Scientific Name Common Name Key No. Fig.

Eleusine

indica . . *.*.oosegrass...... 9 7b . .. * 22

E ymus

canadensis . . . Wild rye. . . . . 56b . . . 71

.9. 52a . . 66 virgini Cus ... * Virginia wild rye

Eragrostis

. . .9 92 Beyrichi... . Love grass. . . . . 75b

* . . . . . 17b, 34 Cazilaris . . * Lace grass.

. . . 9 * . 10b 26 cilianenis . . . . 9 . 9 - 9 9 9 9

curtipedicellata . Short stalked love grass . . 0 . .9 " . 48b . * . 61

" 9 73a . . . -89 lugens. . . . . 9a 24 ilosa. . . . * Indian love grass " 0 . . 65 secundiflora . . Clustered love grass. 51b .

. 9 9 59 sessilisPica . Love grass. . . . . 46a

67a . . , 82 spectabilis. . . Purple love grass .

. . . 83 trichodes. . Love grass...... 67b Eriochloa 87 sericea. . . . Texas cup-grass . . 70a

Festuca . . .* 20 octoflora. .. * Six weeks fescue. * . 5b

Hilaria 43 Belangeri. * Curly mesquite grass. 28b . , .

Hordeu= 7a 21 * . * Little barley . * * 9 . . . . Scientif ic Name Corson Name Key No. Fig. No. Leersia

oryzoides.. . . . ~Pice cutgrass . . . . . 38a . 0 0 53 Leptoloma

cognatuim . . . * Fall witchgrass . . . . 92a . .. 99 Limodea arkansana. 10 . .. 25 Lolium

multiflorum. . . . Italian rye grass 65a . . 70 Manisuris

fylinrica. . . . Pitted jointgrass . 43b . . 58 Melica

mutica . . . . . Two flower melic..* . , 41b .. 56 duhlenberia Reverchoni .. . . 0 0 . . . . 0 0 0 0 . 55b . 69

Oryzsis hMenoides. . . . Indian mountain rice. . 60a . . 75 Panicum

. . . 37 capillare. . . . Vitch grass . . . 21a

fasciculatum Brown top millet. . 0 16a . 32

Haallii . . . . HallAs panicum. . . 68b . 85

obtusum . . . . Vine mesquite grass 26a . 40

. . 79 Scribnerianum. . 0 . 0 0 0 0 0 0 . 0 . * 63a

Reverchoni . . 37a . . .0 51

texanum. . . . . Texas millet; Colorado grass. . . . 14a . . 0 30

Fig. No. ScientifiQ Iame Common Name Key No. 1b 44 virtatm, . - Switch grass. * . . . ..

Papalum * . 86 ciliatif olium...... * - - - . .* * 0 * 6 9 a 55 0 - . - . * . .* . . 41a . . dilatatum. . S * Phalaris

. - 0 - * .0 Sa . .9. 19 canariensis...... Poa

. 0 3a ... 17 annua...... Annual bluegrass. 35a . . 48 ,arachnifera. . Texas bluegrass Schedonnardus 68 Tumble grass. . . . 53a . . paniculatus. . * . Setaria 76a . 93 macrostachya Plains brittle grass. * 8a . . . 23 viridis. . . . * Green brittle grass

Sor hastrum grass. . . . 71a . . 88 nutans 0 0 . . * Indian

Sorghum 50 halepense. . . . Johnson grass . . . 44a .

jporobolus grass. 79b . 96 as p2r. .. * . * Long-leaved rush

51a * 0 64 cryptandrus. . . * Sand dropseed . . . 66a . 81 heter2l.Apsis 18a 35 * - Small rush grass. . neleftus.. .

. . 79b . 96 piA22u3 . .0...... - - . . - . . 0

Scientific Name Common Name Key No. Fig. No.

S tipa leucotricha. . . . Texas needlegrass 82b . . 100 Tri cha chne

californica. . . . Cotton top. . . . 64a . . 80 Triodia

albescens...... S * - - - * - 57a . . 72

74a . " 90 flava. . . * . Purple top.. . 0 . 0 . Trpflasis

17a * 33 purpurea . . . * Sandgrass ......

Uniola

latifolia.. * . . Broadleaf uniola. . .. 43a * " . 57

laxa . . . . Slender spike-grass . 37b . . . 52

CROSS INDEX OF COIvL ON NAMES

Common Name S cientific Name

Annual bluegras s . . . . *oannua

Barnyard grass * . * . . * Echinochloa Crusgali

Berrmuda grass. S. . . . . QCyodon dact.tlon

Big bluestem ...... 2ndrop n 2provincialis

Blue grams . .. .. Bouteloua gra cilis

Broadleaf uniola . . . . . Uniola latifolia

Broom-sedge. * . . . * * Andropogon virinicUP

Brown top mille S.4. . * . canicum fasciculatum Buffalo grass...... Buchloe dactyloides

Bushy beard&)gra ss. . . . . Androp nglomeratus 32

Common Name Scientific Name

Canary grass . . . . . Phalaris canariensis

Chess...... Bromus secalinus

Clustered love grass S. rarostis secundiflora

Cotton top ...... Trichachne californica

Crab grass ...... Digitaria sanuinalis

Curly mesquite grass . . Hilaria BelalnerI

Dallis grass . . . . Paspalum dilatatum

Fall witchgrass. . . .Leptoloma cognatum

Feather fingergrass. . . Chloris virata

Few-flowered aristida. . . Aristida oligantha

Fringed chloris. . . . Chloris cucullata

Goosegrass . . . . * . Eleusine indica

Green bristlegrass .Setaria viridis

Hairy chess...... Bromus commutatus

Hairygrama. . . . . Bouteloua hirsuta

Hall's beardgrass. AndropogonHallii

HallIs panicum . . S. 4anic Hallii

Hedgehog grass . . . Cenchrus echinatus

Indian love grass. Eagrostis pilosa

Indian grass . . . S. orhstrum nutans

Indian mountain grass. Oryzopsis hymenoidea multiflorum Italian rye grass. Lolium

Japanese chess . . . . Bromus japonicus

Johns on grass* ..*. .Jh.. Sorghum . halep ens e Comrmon Name Scientif ic Name

Lace grass ...... Eraorostis illaris

Little barley...... Hordeum Pusillum

Little bluestem...... Andropogon scoparius

Long-leaved rush-grass . . orobolus asper

Love grass ...... Eragrostis Beyrichii

Mesquite grass . . . . . Boutelous uniflora

Pitted joint grass . antsuris yndrica

. . SetariamacrostayehaPlains briotlegrass B

Purple needlegrass . . . . Aristida purpurea

Purple top ...... Triodia flava

Purple love-grass. . . . ragros tisspectabilis

Red top ...... Agrostis alba

Reverchon three-awn . . Aristida glauca

Rescue grass . Bromus catharticus

Rhodes grass ...... Chloris gaya

Rice cutgrass. . . . Leersia ozoides

Sand dropseed...... Sorobolus cryptandrus

Sand grass . . . . . Trilasis pururea

Short-stalked love grass . Eragrostis curtiedicellata

Side-oats grama...... Boutelous curtipendula

Silver beardegrass . . . Andropogon sacharoides

Silvery beard-grass . . . Andropoon ternarius

Six weeks fescue . . . . . Festuca octoflora

Slender spike-grass. . . . Uniola laxa

Small rush-grass . . . . orobolus neglectus 34

Common Na me Scientific Name

Soft chess ....- Bromus mollis

Switchgrass. SPanicum viratum

Texas bluegrass. . . . . Poa richnif era Texas cup-grass. Eriochloa sericea

Texas grama. . . . . Bouteloua rigidiseta -- Panicum texanumTexas millet . . .

Texas needlegrass Stipa leuchotricha paniculatus Tumblegrass. . Schedonnardus

Two-flowered meliLe . . . elica ntica

Vine mesquite gre ss. . . Panicum obtusum

Virginia wild ry S... Evirginicus Smithii Western wheatgra ss . . gropyron canadensis Wild rye . . . . , . Elxmus

Windmill grass. Chloris verticillata

XWitchgrass . . . . . -Panicumcapillare

IND2X OF PLATES

Plate I Plate III Figure Figure 1. Map of Texas showing 3. Culm and leaf of grass Erath County (--after 4. Roots, rhizomes, and base Tharp), Erath County of culms indicated by shaded 5. Leaves, ligule 6. Collar lines. 7. Pubescent bla de and sheath Plate II 8. Ligule wanting 2. Map of Erath County 9. Keel showing general sur- 10. Involute blade node, and innovation face features 11. Stolon, 35

INDEX OF PLATES--Continued

Figure 12. Erose ligule 50. Sor ghum halepense x2 13. Acuminate ligule 51. Uanicum evh 14. Ligule consisting of 52. Uniola laxa x6 ring of hairs 15. Ligule united in tube Plate VII 16. Closed sheath 53. Leersia. Dryzoides x12 54. AndroogniproIn- Plate IV cialis x3 x2 17. Poa annua xIO 55. Faspalum dilatatum 18. Chbloris vertiojllata X91 56. Melica ticaX4u canarienis x4 57. Uniola t~ifolia xl.5 19. Pharlis x6 20. Festuca o oiax20 58. Maniuriscylindrica 21. Hordeum pusillum x15 59. Agrostis alba x5 22. Eleusine indica x3 60. Eragrostis aessilis- 23. Setaria!viridi5 x6 pisa x10 rgrostis pilosa x20 61. Eragrostis curtipedic- 24. x5 25. Limnodea arkansana x6 &llata r10 62. Aristida glauca x1l 26. Eraros tis cilianen &"* purpurea x10 Cenchrus chinatus x3 63. AristId 27. crpndrus x6 28. Aristida oligantha xiQ 64. tSporobolus Plate V Plate VIII Bromus secalinus x7 65. Eragrotis. secundi- 29. flora x5 30. Panicum texanum x3 virgata x3 66. lymus virginicus x3 31. Chloris x 7 32. Tanicum as caculatumu x2 67. Chloris gayana re2a x5 68. 7chedonnardus Pani- 33. Triplasis~j2p cula tus R10 34. Era os tIs cparis x10 x20 69. ]Vluhlenbergia Rever- 35. snglectus choni x12 364 Bromus mollis x6 70. Lolium multiflorum x4 japonicus x6 canadensis x2 conmutatus x6 71. Elymus 72. Triodia albescens x4 374 Pani~ ~~caup11are x3 x3- 73. Bouteloua gra cilis x11 38.0I Digitaria sanguinais x3 74. Chloris cucullata x10 394I Bromus catharticus 75. oides x15 PanicumWobtusumx5 40 76. Andropogon sacchoroides x3 VI Plate Plate IX 414.S rynIdon dactylon x6 .S 77. Echinochloa Cru alli x6 42,4 -Buoqh7loe daf:I6idesx9 78. Sou te91olia r~ ~x 43 4 virga-tum x4 79. Panicum worlb- 44 anicum nerianum x3 S curtipendula x5 45 .S Bouteloua 80. Tri'hachne calif or- 46 Bouteloua untiflora x8 Asron Srithii x5 nica x6.i 2 47 81.0 pobou heterolei x20 48 Tgia chniea x5 spec- x4 82. Eragrostis 49 .7ndropogon Halmlii tabilis x5 36

INDEX OF PLATES---Continued

Plate IX--_con. Figure 83. Eragrostis trichodes x4 84. Andro o on iomeratus x5 85. Tn Cum1l18 86. uciliatifoliu x3 87. Eriochloa sericea x6 88. orattrum nutans x2.

Plate X 89. Erarostis lugens x12 90. Trioda flava x3 91. BouteloiThirsuta x12 92 jrgr osi Brih 4 93 $etaria macros 'Iah x6 94. perforatusX44ndropogon 95*. ndrop0on n icu0 x6 96. Sporobolus pilosus x6 97. dropogon scoparius x9 98. AndropOg n ternarius X9 99. Leptolomacoiatum X9 1000 3 paleucotrIca X4 I

Pate

1. Long-leaf pin.e. 2. Coastal prairie. Z. Feyette prairie. 4. Mesquite---ohaparrrl.

5. Coastal sand dunes.

6. Granitic Boll with oak and mesquite. 7. Edwards Plateau, oak---ceder. 8. Mountains: Gaudalupe, Davis, Glas, Crthedral, Chensti, Chiaos.

9. Live-oak, mesquite and Acacia on short grase.

10. Trans-Peco@:Sotnl lechuguilla. 11. Sandy south plains. 12. High plains. Fig.l 13. Mesquite---grassland.

14. Western cross timbers, oak---hickory.

15. Eastern cross timbers, oak---hickory. 16. Oak---hickory. 17. Loblolly pine, short-leaf Dine and oak---hickory.

18. Black land prairie.

-- after Benjamine C.Tharp. 38

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