SMITHSONIAN CONTRIBUTIONS TO BOTANY NUMBER 49

A Scanning Electron Microscope Survey of the Epidermis of East African Grasses, I

Patricia G. Palmer and Alice E. Tucker

SMITHSONIAN INSTITUTION PRESS City of Washington 1981 ABSTRACT Palmer, Patricia G., and Alice E. Tucker. A Scanning Electron Microscope Survey of the Epidermis of East African Grasses, I. Smithsonian Contributions to Botany, number 49, 84 pages, 9 figures, 48 plates, 1981.-In developing a reference collection as a standard for using fossil grass cuticles as a paleoeco- logical tool, we have examined leaf epidermal features of grasses with SEM. Anatomical structures are described, and a system of categorizing diagnostic features is proposed. Descriptions (abaxial and adaxial surfaces) of 24 East African species are presented comprising ten tribes: Bambuseae, Olyreae, Phareae, Streptogyneae, Oryzeae, Phyllorhachideae, Ehrharteae, Arundineae, Dant honieae, and Centosteceae.

OFFICIALPIJBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution’s annual report, Srnithsoniun Year. SERIESCOVER DESIGN: Leaf clearing from the katsura tree Cercidiphyllurn japonicurn Siebold and Zuccarini.

Library of Congress Cataloging in Publication Data Palmer, Patricia G A scanning electron microscope survey of the epidermis of East African grasses. (Smithsonian contributions to botany ; 49) Bibliography: p. Includes index. 1. Grasses-Africa, East-Anatomy-Atlases. 2. Grasses-Anatomy-Atlases. 3. Leaves- Anatomy-Atlases. 4. Epidermis-Atlases. 5. Ultrastructure (Biology)-Atlases. I. Tucker, Alice E., joint author. 11. Title. 111. Series: Smithsonian contributions to bot- any; no. 49. QKl.S2747 no. 49 [QK495.G74] 581s [584’.909676] 80-19201 Contents

Page Introduction ...... 1 Materials and M ...... 2 Acknowledgments ...... 2 Diagnostic SEM Features ...... 2 Stomata ...... 3 Long Cells ...... 3 Interstomatal Cells ...... 3 Papillae ...... 4 Short Cells ...... 4 Silica Bodies ...... 4 Microhairs ...... 5 Prickles ...... 5 Macrohairs ...... 5 Figures ...... 6 Format for Species Descriptions ...... 15 Tribe BAMBUSEAE...... 15 Arundinaria alpina K. Schumann ...... 15 Oreobambos buchwaldii K. Schumann ...... 16 Oxytenanthera abyssinica (A. Richard) Munro ...... 16 Puelia olyriformis (Franchet) Clayton ...... 17 Tribe OLYREAE...... 18 Olyra latifolia Linnaeus ...... 18 Tribe PHAREAE...... 18 Leptaspis cochleata Thwaites ...... 18 Tribe STREPTOCYNEAE...... 19 Streptogyna crinita P. Beauvois ...... 19 Tribe ORYZEAE...... 20 Leersia hexandra Swartz ...... 20 Maltebrunia leersioides Kunth ...... 20 Oryza punctata Steudel ...... 21

Tribe PHYLLORHACHIDEAE. . , , ...... 22 Humbertochloa greenwayi C. E. Hubbard ...... 22 Phyllorhachis sagittata Trimen ...... 22 Tribe EHRHARTEAE...... 23 Ehrharta erecta (Lamarck) var. abyssinica (Hochstetter) Pilger ...... 23 Tribe ARUNDINEAE...... 24 Phragmites mauritianus Kunth ...... 24 Tribe DANTHONIEAE...... 24 Asthenatherum glaucum (Nees) Nevski ...... 24 Crinipes abyssinicus Hochstetter ...... 111 iV

Elytrophorus globularis Hackel ...... , , ...... , , , , . , , , 26

Habroch loa bullockii H u bbard , , . . . . , , , ...... , , , . , , . 26 Neyraudia arundinacea (Linnaeus) Henrard ...... 27

Pentaschistis borussica (K. Schumann) Pilger , . , , , , , , , , , , , , , , , , 28

Triraphis schinzii Hackel . , , , . . . . , ...... , . , . . . , . . . . , . , . . , . 28

Tribe CENTOSTECEAE. , . . , , ...... , . , . . . . , . , . , , ...... , , , , , , , 29

Bromuniola gossweiieri Stapf and C. E. Hubbard . , ...... , . , . , , , . , , 29

Megastachya mucronata (Poiret) P. Beauvois , , , , , , , , , , , , , , , , , , , , , , 30

Orthoclada africana Hubbard . . . , , . . , ...... , ...... , . . . 30

Appendix: Material Studied . . , . . , , , . , , . . , . . , , ...... 32 Literature Cited ...... 34 Plates ...... 35

Index to Grass Species ...... , . . . , . . , , . . , . . , , . . . . . , ...... , , . . . , 84 A Scanning Electron Microscope Survey of the Epidermis of East African Grasses, I

Patricia G. Palmer and Alice E. Tucker

Introduction tion of Africa and may even permit the recon- struction of paleotemperatures. The taxonomic value of epidermal features of Pollen analysis by itself cannot provide all the grass leaves in identifying and classifying mem- information we need about the vegetational his- bers of the family is well established (Prat, 1932, tory of Africa, because grass pollen is identifiable 1936; Tateoka et al., 1959; Metcalfe, 1960; Jac- only to family. Many lake core samples from East ques-Fklix, 1962). Traditionally the microanat- Africa, which are rich in grass pollen, contain omy of grass leaves has been studied with light charred fragments of grass epidermis identifiable microscopy, but Palmer (1976) has shown that to tribe or even to genus (Palmer, 1976). These the diagnostic features of grass cuticles are re- charred fragments presumably were deposited markably well suited for study with scanning during naturally occurring fires and in modern electron microscopy. Palmer (1976) applied this time during fires associated with the activities of technique not only to modern day grasses but man. Consequently, vegetation types prone to extended it to fossil grass cuticular fragments burning may be overrepresented in the fossil rec- from East African lake sediments where the ord. Many vegetation types, however, are both opaqueness of the charred cuticles makes obser- rich in grasses and subject to burning: steppe, vation with light microscopy inadequate. grassland, savanna, and woodland. This tech- The potential for the use of grass cuticles as a nique will allow discrimination among these veg- new paleoecological tool led to this present study. etation types. Grasses are an important element in many mod- The charred appearance may also be a result ern vegetation types in Africa, and recently Liv- of chemical changes after deposition. In any case, ingstone and Clayton (1980) have shown that the fossil material is very well preserved and is there is high correlation between the percentage remarkably similar to modern leaves. Recent core of Cq grasses and temperature in East Africa. samples from Lake Bosumtwi in Ghana, West Better interpretation of grasses in the fossil record Africa, have revealed macroscopic fossilized grass will allow clearer understanding of past vegeta- leaves in great abundance and so intact that in many cases when observed with the scanning Patricia G. Palmer, Department of Biology, Louisburg College, electron microscope even the fragile apical cells Louisburg, N. C. 27549. Alice E. Tucker, Department of Zoology, Duke University, Durham, N. C. 27706. of the bicellular microhairs are visible. 1 2 SMITHSONIAN CONTRIBUTIONS TO BOTANY

The possibility of using grass cuticles in a stra- several species were examined to determine intra- tigraphic analysis of African lake sediments has generic variability. In some cases more than one made it necessary to develop a reference collection specimen of a species was examined to determine of modern grasses as a standard of comparison. intraspecific variability. Since most of the available lake cores are from AcmowLEmMmTs.-We are especially grate- East Africa, we decided first to survey the genera ful to D. A. Livingstone of the Zoology Depart- of East African grasses with scanning electron ment, Duke University, for research support and microscopy. We delimit East Africa to include for encouragement in this study. We appreciate Uganda, Kenya, and Tanzania, the region dealt suggestions on this study and comments on the with in “Gramineae” by Clayton (1970, 1974, in manuscript from T. Soderstrom, S. Renvoize, and prep.) in Flora of Tropical East Africa. We also D. Livingstone. V. Pearson deserves thanks for follow the nomenclature of Flora of Tropical East her assistance in the preparation of the manu- Africa. As the need arises we can expand our script. S. Hutchison provided assistance with reference collection to include other areas of Af- technical aspects of this study including some rica or the world where we are likely to be iden- scanning electron microscopy. We also wish to tifying fossil grass material. This paper presents thank W. D. Clayton and S. Renvoize of the Kew the results of the first part of this survey and Herbarium, T. Soderstrom of the National Her- includes 24 genera representing ten tribes: Bam- barium, and G. Davidse of the Herbarium of the buseae, Olyreae, Phareae, Streptogyneae, Ory- Missouri Botanical Garden for providing material zeae, Phyllorhachideae, Ehrharteae, Arundineae, for study. We are grateful for technical assistance Danthonieae, and Centotheceae (Centosteceae, by T. Caspar. This research was supported by Soderstrom and Decker, 1973). NSF grants BMS75-03441 and DEB76-80426 to MATERIALSAND METHODS.-Leaf material for D. A. Livingstone. scanning electron microscopy (SEM) was taken from dried herbarium material. A section from Diagnostic SEM Features the middle portion of a blade from an upper, mature, undamaged leaf was chosen for study. In The most complete compendium of descrip- a few cases, where the epidermis proved to have tions of epidermal features of grasses is that of a heavy coat of epicuticular wax, the wax was Metcalfe (1960). We have frequently referred to removed by soaking in xylene from 12 to 14 Metcalfe’s study, and in particular we have used hours. Two pieces of the leaf (one exposing the his system of cell orientation where the longitu- abaxial or lower surface, the other exposing the dinal axis of the leaf is referred to as the “hori- adaxial or upper surface) were mounted on stubs zontal” dimension and the direction at right an- with double-coated Scotch tape. The specimens gles to the long axis becomes “vertical” for de- were sputter-coated with gold-palladium, ob- scriptive purposes (see Metcalfe, 196O:xix). All served with a JEOL T20 scanning electron mi- photomicrographs are oriented so that the longi- croscope, and photographed using Polaroid P/N tudinal axis of the leaf is “horizontal” in the field 665 film. The photomicrographs are deposited in of view, but we have found it necessary to modify the laboratory of D. A. Livingstone, Department his terminology and develop a system more ap- of Zoology, Duke University. propriate for features viewed with SEM. Scan- Each specimen was analyzed at the microscope ning electron microscopy enables us to examine using a standard check sheet of diagnostic fea- certain structures more clearly than with light tures. By comparing the photomicrographs and microscopy, and some features have a different the check sheets, a complete description of each aspect when viewed with SEM as compared to taxon was compiled. At least one species of each light. We have established the following system genus was examined, and for some large genera of classification and terminology of epidermal NUMBER 49 3 features. This system is used as a standard the horizontal axis being parallel to the longitu- throughout our study, minor modifications being dinal axis of the leaf. We recognize the following made as the need arises. shapes of long cells: Square (cell about as long horizontally as it is wide vertically; STOMATA Figure 2a) Rectangular (cell about two to three times as long as wide; Each grass leaf stoma or opening is bounded Figure 2b) by a pair of guard cells having narrow middles Pentagonal (Figure 2c) and enlarged ends and a subsidiary cell adjacent Hexagonal (Figure 24 Long and narrow (cell more than three times as long as to each guard cell. The subsidiary cells have a wide, width uniform; Figure 2e) distinctive shape and stand out sharply against Long and narrow (cell more than three times as long as the background of regular epidermal cells. Ma- wide, width non-uniform, usually wider in the middle and ture grass stomata can be classified according to tapered at ends; (Figure 2A the shapes of these subsidiary cells as seen in The outline of the long cell walls as they abut surface view. We recognize four types of subsidi- cells in an adjacent horizontal row is categorized ary cells according to Metcalfe’s (1960) system: as non-sinuous (Figure 2e) ; slightly sinuous (Fig- Parallel-sided (Figure la) ure 3a); markedly sinuous, interlocking, raised Low-dome (Figure lb) (Figure 36); or markedly sinuous, interlocking, Triangular (Figure lc) flat (Figure 3c). High-dome (Figure Id) The presence or absence of papillae on long Special features of stomata are also described. cells is noted. If papillae are present, the number, In some genera (e.g., all of the tribe Oryzeae) distribution (i.e., row or rows, paired, irregular), papillate subsidiary cells occur (Figure lf). Oc- shape (globose or elongate), and size (uniform or casionally, the stomata are obscured by overarch- variable) are described (see section “Papillae”). ing papillae (see section “Papillae”) from adja- cent epidermal cells (Figure le) or are sunken in INTERSTOMATALCELLS grooves so that the shape of the subsidiary cells cannot be determined. The long cells that occur in the same horizontal Frequency and distribution of stomata are use- row as the stomata and that separate individual ful characters. Frequency is indicated according stomata are termed interstomatal cells or intersto- to four categories: absent, infrequent, common, matals (i.e., cells between stomata). Several cate- abundant. Stomata alternating with long cells gories of shapes of these cells are recognized: (interstomatal cells) occur as one or more hori- square, rectangular, pentagonal, hexagonal, long zontal bands in the intercostal (between veins) and narrow with uniform width, or long and zones. A band may consist of a single row or narrow with non-uniform width (see section several adjacent rows of stomata. Distribution “Long Cells”). The manner in which the end comprises the number of stomata1 bands per in- walls fit against the stomata is described as tercostal zone as well as the number of rows per straight to convex (Figure 34; slightly concave band. or U-shaped (Figure 3e); or markedly concave or V-shaped (Figure 3f). LONGCELLS The outline of the interstomatal walls as they abut cells in an adjacent horizontal row is cate- There are two types of epidermal cells in gorized as non-sinuous; slightly sinuous (Figure grasses: long cells and short cells. The bulk of the 3a); markedly sinuous, interlocking, raised (Fig- intercostal zone consists of long cells, which usu- ure 36); or markedly sinuous, interlocking, flat ally are much longer horizontally than vertically, (Figure 3c). 4 SMITHSONIAN CONTRIBUTIONS TO BOTANY

The presence or absence of papillae on inter- to as short cells. In many cases these cells are stomatals is noted. If papillae are present, the about as long as wide (unlike long cells that are number, distribution, shape, and size are de- commonly longer than wide), but their dimen- scribed (see sections “Papillae” and “Long sions can vary. Cells”). Note is made of the location of short cells, i.e., costal (over the vein) or intercostal (between PAPILLAE veins), and the distribution in each zone is de- scribed as solitary, paired (usually a cork cell and Protrusions from the outer walls of epidermal a silica cell), three to five cells per row, or more cells are termed papillae. Papillae occur primarily than five cells per row. When the short cells occur on long cells, including interstomatals, but we in rows, the cork and silica cells usually alternate. have observed papillate cork cells, subsidiary The frequency of silica cells and cork cells is cells, and even macrohairs with papillate shafts. indicated by four categories: absent, infrequent, In some instances, the papillae seem to be very common, and abundant. For all features of short thin-walled and fragile with a collapsed or de- cells, it is important to make clear in the descrip- flated appearance. On the other hand, papillae tion whether the cells are costal or intercostal, may be very thick and heavily cutinized (Met- since in a single leaf the costal short cells may be calfe, 1960) or silicified (Clark and Gould, 1975) very different from the intercostal ones. and remain rigid rather than becoming collapsed. Cork cells are not so easily detected with SEM Since papillae protrude from the cell surface, as with light and may sometimes be overlooked. they are well-suited for examination with SEM, When advisable the specimen is checked under and we believe that the taxonomic importance of light for verification. papillae may be greater than realized with light microscopy. SILICABODIES For various cells that possess papillae-notably the long cells-we indicate the number of pa- A silica cell usually contains a silica body that pillae per cell. The number varies from a single may or may not assume the same shape as the papilla per cell (Figure 4a) to a pair to many cell. Differences in the shape of the silica body (Figure 4b,c,df). We note the distribution of the within the silica cell have great taxonomic value. papillae on a cell: papillae occurring in a single We assume that the shape seen on the surface row (Figure 46) or in several rows; occurring in with SEM is that of the silica body and recognize pairs; irregularly distributed (Figure 4c). Two the following types, which are basically those of shapes are recognized: globose (Figure 46,c,d) and Metcalfe (1960) with a few minor modifications. elongate (Figure 4e). Size is denoted as uniform Our categories are based as much as possible on (Figure 46) or variable (Figure 4c). In some in- well-known geometrical shapes, and we have stances we note whether the papillae are large eliminated the use of generic names to describe (Figure 4c,d) or extremely small giving a warty types: appearance (Figure 4fl. Although a papilla is Tall and narrow (a shape described by Metcalfe, but not yet usually a single structure, there are examples of encountered in this study) compound ones, especially double or forked (Ter- Crenate-vertical (Figure 5a) re11 and Wergin, 1979) (Figure 4.4. Figure-eight (Metcalfe’s Oryta type; Figure 56) Saddle-shaped (Figure 5c) Elliptical (Figure 5d) SHORTCELLS Round (Figure 54 Crescent-shaped (Figure 5d) Epidermal cells that contain silica bodies (silica Cross-shaped (Figure 5e) cells) or that are suberized (cork cells) are referred Acutely-angled (Figure 5A NUMBER 49 5

Square (Figure 6a) calfe (1960) refers to these as prickle-hairs. These Oblong (Figure 66) appendages occur in both costal and intercostal Elongate-smooth (a shape described by Metcalfe, but not zones. We note the absence or presence of prickles yet encountered in this study) Elongate-sinuous (Figure 6c) and, if present, their frequency of occurrence- Nodular (Figure 64 infrequent, common, or abundant-and location. Dumbbell (Figure 64 This quantitative character of frequency of pric- Ends rounded (Figure 6fl, or straight (Figure 6f13 or kles may not be as reliable as the qualitative concave (Figure 6e) characters, since we and others (Metcalfe, 1960; Middle wide (Figure 6ef) or middle narrow Middle long (Figure 6A or middle short (Figure 6e) Stewart, 1965a,b) have observed that the abun- dance of prickles varies from one specimen to another within a species. MICROHAIRS We recognize two main types of prickle-like Microhairs are small, usually two-celled (some- appendages: prickles are large with a pointed times unicellular), epidermal appendages com- apex and a swollen base and more often occur prised of a basal cell and an apical cell. The cells costally (Figure 8a,b); hooks are smaller, with a of the microhair are very thin and fragile, partic- more abruptly pointed apex and a more promi- ularly the apical cell, which is often missing or nently swollen base and usually occur in the when present is often deflated and distorted. Mi- intercostal region (Figure 8a (arrow) ,c). The two crohairs are found in the intercostal zone, both in often intergrade and in some cases it is difficult and between stomata1 bands. to decide whether an appendage should be cate- The features of microhairs that are useful for gorized as a prickle or a hook. diagnostic purposes are presence or absence (the In addition to the more common prickles and Pooid grasses and other occasional genera lack hooks, we have occasionally encountered unusual microhairs), number of cells (one or two), propor- prickle-like appendages. In Asthenatherurn, for ex- tional length of basal and apical cells, length- ample, there are large, straight, bluntly pointed width ratios of cells, and nature of apex (rounded appendages without swollen bases that resemble or tapered). This last feature can be determined short macrohairs (see section “Macrohairs”) (Fig- only when the apical cell is neither collapsed nor ure 84. Another unusual prickle-like appendage distorted. observed in Asthenatherum is a short, unpointed The diagnostic characters that we recognize appendage with a swollen base that we describe are the following: as a papillate prickle since it resembles a papilla

One-celled (Figure 7a) (Figure 8e). In a few cases we have found what Two-celled, basal and apical equal in length, short (cells one appears to be a bicellular prickle (Figure 8J). to two times as long as wide) (Figure 76) Two-celled, basal and apical equal in length, medium (cells three to four times as long as wide) (Figure 7c) Two-celled, basal and apical equal in length, long (cells five MACROHAIRS or more times as long as wide (Figure 74 Two-celled. basal longer than apical (Figure 7e) Macrohairs are larger than the microhairs de- Two-celled. basal shorter than apical (Figure 7fl scribed earlier, and often they can be seen with Nature of apex the unaided eye or with very low magnification Rounded (Figure 7c) (X 5-10). Unlike the bicellular microhairs, ma- Tapered (Figure 7e) crohairs are usually one-celled, although special- PRICKLES ized basal epidermal cells may be associated with them. Prickles are robust, usually sharply pointed, The presence or absence of macrohairs is de- epidermal appendages with swollen bases. Met- termined for both the costal and intercostal zones. 6 SMITHSONIAN CONTRIBUTIONS TO BOTANY

FIGURE1 .-Stomata1 features: a, parallel-sided subsidiary d, high-dome subsidiary cells, ahaxial Chlorocahmma crytocan- cells, ahaxial Helictotrichon elongatum (A. Richard) Hubbard, tha Clayton, Greenway and Kanuri 13980, X 1696: e, stoma Liehenberg 12, X 867; b, low-dome subsidiary cells, ahaxial obscured by overarching papillae, abaxial Arundinarza alpina, Echinochloa pyramidalis (Lamarck) Hitchcock and Chase, Or- Mayer 7750, X 1285; f. papillate subsidiary cells, abaxial taggeup 372, X 1696; c, triangular subsidiary cells, abaxial Maltebrunia leersioides. Humbert 5783, X 2970. Eleusine coracana (Linnaeus) Gaertner, de Wet 3833, X 1285: NUMBER 49 7

FIGURE2.-Long cell shapes: a, square, abaxial Coelachne Snowden, Thomas 4544. X 867: t, long, narrow, width africana Pilger. Schlieben 4161, X 867; b, rectangular. adaxial uniform, abaxial Avena abyssinica A. Richard, Pappi 4901, Crinipes ubyssinicus Gay s.N.. X 867; c. pentagonal, abaxial X 295; long. narrow, width non-uniform, abaxial Dac@lis Comrnelinidium mayumbense (Franchet) Stapf, Chandler 1859, glomerata Linnaeus, Gillett 15753, X 416. X 295: d, hexagonal, abaxial Sacciolepis africana Hubbard and 8 SMITHSONIAN CONTRIBUTIONS TO BOTANY

FIC~JRE3.-Long cell wall outlines (a-c) and end walls of adaxial Ohra latijiolia, Palmer 901, X 867; d, straight to inttrstomatals (d-f): a, slightly sinuous, abaxial Or/hoclada convex, abaxial Sorghum arundinaceum Stapf, Myre 26, X 295; africana, Paterson s.n., X 867; 6,markedly sinuous, interlock- e, slightly concave, abaxial Orthoclada africana, Paterson S,n., ing, raised, abaxial Phacelurus huillensis (Rendle) Clayton, X 1696; J markedly concave, Triraphis fleckii Hackel, Webster T238, X 867; c, markedly sinuous, interlocking, flat. Schweickerdt 21 15, X 625. NUMBER 49 9

FIGURE4.-Papillae: a, single papilla per long cell. abaxial papillae, adaxial Lepturus repens (G. Forster) R. Brown. Bog- Echinochloa colona (Linnaeus) Link, de Wet 5416, X 295: dan 3642, X 867: e, elongate papillae. abaxial Vossia cusprdata b, single row of papillae per long cell, abaxial Daknopholis (Roxburgh) Griffith. Meyer 7503. X 867: ,J small. variable- boiuznzi (A.Camus) Clayton, Croat 30897, X 867: c, numerous sized papillae giving surface a warty texture. abaxial Orh- papillae per long cell, size variable, abaxial Or)ira barthiI clada afrrcana, Paterson s.n.. X 2970. A. Chevalier. de Wet 633, X 416: d, globose and compound 10 SMITHSONIAN CONTRIBUTIONS TO BOTANY

FIGURE5.-Silica bodies: a, crenate-vertical, abaxial Olyia drageana Steudel. Schweickerdt 18 18. X 867: e, cross-shaped, latfolia, Palmer 90 1, X 867: b, figure-eight, abaxial Oryra abaxial Phacelurus huiliensis (Rendle) Clayton, M’ebster T238, barthiz A. Chevalier. de Wet 626, X 1285: c. saddle-shaped, x 867: f. acutely-angled. adaxial Hetemanthoecia guineensis abaxial Chysochloa hindsii Hubbard. Lewalle 4841. X 867: (Franchet) Robvns, Simon and Williamson 1925. X 1696. a’. crescent-shaped (arrow). elliptical to round. abaxial Stzpa NUMBER 49 11

FIGURE6.--Silica bodies: a, square, abaxial Colpodium chion- Schweickerdt 2158, X 867: e, dumbbell. ends concave, mid- ogeiton (Pilger) Tzvelev, Wood 923, X 867: b. oblong, abaxial dle wide, short, abaxial Schmidtia bulbosa Stapf, Brass 17909, Tritzcum aestivum Linnaeus, Harshberger 1 139, X 867; X 867: f. dumbbell, ends straight to rounded, middle wide, c. elongate-sinuous, abaxial Avena abjssznica Hochstetter, long, abaxial Trichoneura mollis (Kunth) Ekman. Kapper 550. Pappi 4901, X 867: d, nodular, abaxial Ell'trophorusp.lobularis, X 867. 12 SMITHSONIAN CONTRIBUTIONS TO BOTANY

FIC~JRE7.-Microhair types: a, one-celled, abaxial DacQloc- long, apex tapered, abaxial Orlhucladu ayricana, Paterson sn., tenzum giganleum Fisher and Schweick, Bullock 305, X 1696; X 1285; e, two-celled, basal longer, apical shorter, apex b, two-celled, basal and apical equal, short, apex rounded, tapered, abaxial Harpachne schimperi Hochstetter, Milne-Red- abaxial Cpodon dac!ylon (Linnaeus) Persoon. Hitchcock head and Taylor 8828, X 867; f. two-celled, basal shorter. 24507, X 2970; c. two-celled, basal and apical equal. me- apical longer, apex tapered, abaxial Ebtrophorus globularis, diurn, apex rounded, abaxial Humbertochloa greenwuyi. M'ing- Schweickerdt 2158, X 1285. field 1680, X 1285; d. two-celled, basal and apical equal. NUMBER 49 13

FIGURE8.-Prickles: a, costal prickles and intercostal hooks straight. stiff. ends blunt. bases not swollen. abaxial Asth~n- (arrow), abaxial Sehima nercosum (Rohburgh and Willdenow) atherum forskalii (L-ahl) Nevski, Lfandaville 388. X 63; Stapf. Hudson 217, X 295: b. costal prickle. abaxial Dichan- e. papillate prickles, short, unpointed with swollen bases. thium aristatum (Poiret) Hubbard. Evles 2210. X 1285; adaxial of .4sthenatherum forskalii, Mandaville 388. X 295: /, c. intercostal hook; abaxial Brachiaria brizanthn Stapf, Hitch- bicellular prickle. adaxial .Wegustachy mucronatn. Faden 74/ cock 24884 X 867: d. short macrohair-like prickles. large. 345. X 867. 14 SMITHSONIAN CONTRIBUTIONS TO BOTANY

FIGURE9.--Macrohairs: a, raised basal cells absent, abaxial of macrohair curved. adaxial Orthoclada africana, Paterson Isachne buettneri Hackel, Baldwin 6718. X 867: 6, basal cells s.n., X 625; e, short macrohair, adaxial Oropelium lhomaeum slightlv raised. abaxial Andropterum stolziz (Pilger) Hubbard. (Linnaeus) Trinius, Olufsen 393, X 867; J papillate shaft of Wiehe N/293. X 4 16: c, basal cells markedly raised, abaxial macrohair, abaxial Danthoniopsis uiridis (Rendle) Hubbard. Cleistachne sorghoides Bentham, Thomas 1325, X 867: d, end Verhoon 1373, X 1285. NUMBER 49 15

When present, the frequency is divided into three Tribe BAMBUSEAE categories: infrequent, common, and abundant. Sometimes there is quantitative variation within Arundinaria alpina K. Schumann a species, and therefore, as with prickles, this PLATES1-2 character may not be as taxonomically valuable as other features. Note is made of the presence ABAXIAL (Figure 96,c) or absence (Figure 9a) of raised epidermal cells at the base of the macrohairs and, SToMATA.-common; appears to be high-dome when present, whether the cells are slightly (Fig- but not clear because of overarching papillae; 1 ure 96) or markedly (Figure 96) raised. stomata1 band/intercostal zone, 1 or sometimes 2 Occasionally, we have seen structures that are rows/band (Plate la&). intermediate between macrohairs and prickles INTERSTOMATALCELLS.-LOng, narrow, width (Figure 9e). In such cases, the feature is assigned uniform; ends indeterminable because of over- to one category and cross-reference is made to the arching papillae; markedly sinuous, interlocking, other. flat to slightly raised. Papillae: Many, usually In our survey of grass epidermis we have en- single row, globose, uniform, or sometimes none countered some specialized features of macro- seen (Plate la). hairs. In Orthoclada africana C. E. Hubbard, the tip LONGCELLs.-Long, narrow, width uniform; of the macrohair is curved forming a fishhook markedly sinuous, interlocking, flat to slightly type macrohair (Figure 9d). Another unusual fea- raised. Papillae: Many, usually single row, glo- ture is the papillate shaft of the macrohair in bose, uniform, or sometimes none seen (Plate Danthoniopsis uiridis (Rendle) Hubbard (Figure lc,e). PRIcKLEs.-Infrequent; intercostal prickles 98. (Plate Id). SHORTCELLs.-costal >.!)/row; intercostal sol- Format for Species Descriptions itary or paired. Silica Cells: Costal common; intercostal abundant. Cork Cells: Costal com- mon; intercostal abundant (Plate lc,e). SToMATA.-Frequency; subsidiary cell shape; distribution; special features. SILICA BoDIEs.-costal dumbbell, ends INTERSTOMATALCELLs.-shape; end walls; out- rounded to straight, middle wide and short; in- line of walls. Papillae: Number/cell, distribution tercostal saddle-shaped (?), not very distinct, shape difficult to ascertain (Plate lc,e). on each cell, shape, size. LONGCEus-Shape; outline of walls. Papillae: MICROHAIRS.-Infrequent, found near the mar- gin only; two-celled; basal and apical equal in Number/cell, distribution on each cell, shape, length, medium; apex rounded (Plate lf). size. PRICKLES.-Frequency; location and type. MACROHAIRS.-None seen. SHORTCELLs.-Location and distribution. Sil- ADAXIAL ica Cells: Location and frequency. Cork Cells: Location and frequency. SToMATA.-Infrequent; probably high-dome SILICABoDIEs.-~ocation and shape. but not clear because of overarching papillae: MIcRoHAIRs.-Frequency; number of cells; distribution indeterminable because stomata too shape; shape of apex. infrequent (Plate 2a). MACROHAIRS.-Frequency; location; nature of INTERSTOMATALCELLs.-Long, narrow, width base. uniform; ends indeterminable because of over- SPECIALFEATvREs.-Description of unique fea- arching papillae; markedly sinuous, interlocking, tures not covered in other categories. flat to slightly raised. Papillae: Many, single row, 16 SMITHSONIAN CONTRIBUTIONS TO BOTANY globose, uniform or sometimes none seen (Plate MIcRoHAIRs.-Abundant; two-celled; basal 26). longer, apical shorter; apex rounded (often de- LONGCELLS.-Long, narrow, width uniform; flated) (Plate 3e). markedly sinuous, interlocking, flat or slightly MACROHAIRS.-cOmmOn; costal; basal cells raised. Papillae: Many, single row, globose, uni- slightly raised; papillate around the base (Plate form or sometimes none seen (Plate 26). 3f). PR1cKLEs.-Infrequent; intercostal prickles or hooks (somewhat intermediate between prickles ADAXIAL and hooks) (Plate 24. SToMATA.-Infrequent; appears high-dome but SHORTCELLs.-costal >5/row; intercostal sol- somewhat obscured by overarching papillae; sto- itary or paired. Silica Cells: Costal common; mata too infrequent to form a regular distribu- intercostal abundant. Cork Cells: Costal com- tional pattern (Plate 4a,b,c). mon: intercostal abundant; some appear cross- INTERSTOMATALCELLs.-Rectangular; ends shaped (Plate 2ef). straight to convex; markedly sinuous, interlock- SILICABoDIEs.-costal dumbbell, ends straight ing, raised. Papillae: Few toward the ends and to concave, middle wide and ,short; intercostal overarching the stomata, globose, variable; usu- tall and narrow (Plate 2ef). ally many long cells separating the sporadically MIcRoHAIRs.-None seen. distributed stomata (Plate 4a,c), MACROHAIRS.-NOne Seen. LOXGCELLs.-Long, narrow, width uniform; markedly sinuous, interlocking, raised. Papillae: Oreobarnbos buchwaldii K. Schumann None seen. It is difficult to distinguish between PLATES3-4 costal and intercostal regions; a distinctive feature in the intercostal (?) is a wide band of long cells, ABAXIAL the ends of which are not discernible (Plate 4a,d). PRIcKLEs.-None seen. SToMATA.-Abundant; appears high-dome but SHORTCELLs.-Costal and intercostal paired. not clear because of overarching papillae; 2 sto- Silica Cells: Costal and intercostal abundant. matal bands/intercostal zone, 3 rows/band (Plate Cork Cells: Costal and intercostal abundant 3a,6). (Plate 4ef). INTERSTOMATALCELLs.-Square to rectangu- SILICABoDIEs.-costal and intercostal inter- lar; ends indeterminable because of overarching mediate between saddle-shaped and figure-eight papillae; outline of walls indeterminable. Papillae: (Plate 4ef). Many, irregular, globose, variable (Plate 36). MIcRoHAIRs.-None seen. LONGCELLs.-Rectangular to long, narrow, MACROHAIRS.-None seen. width uniform; outline of walls indeterminable. Papillae: Many, irregular, globose, variable (Plate 3a,e). Oxytenanthera abyssinica (A. Richard) Munro PRIcKLEs.-Common; intercostal prickles PLATES5-6 (Plate 3a). SHORTCELLs.-Costal paired or 3-5/row; in- ABAXIAL tercostal paired. Silica Cells: Costal and inter- costal abundant. Cork Cells: Costal and intercos- SToMATA.-Abundant; triangular; 1 stomata1 tal abundant (Plate 364. band/intercostal zone, 5-8 rows/band; stomata SILICABoDIEs.-costal saddle-shaped; inter- somewhat obscured by overarching papillae costal saddle-shaped, cross-shaped, or somewhat (Plate 5a,b). like the figure-eight type (Plate 364. INTERSTOMATALCELLs.-Rectangular or some- NUMBER 49 17 times square; nature of ends indeterminable be- Puelia olyriformis (Franchet) Clayton cause of papillae; outline of cells indeterminable. Papillae: Many, irregular, globose, variable PLATES7-8 (Plate 5c). LONGCELLs.-Rectangular; outline of cells in- ABAXIAL determinable. Papillae: Many, irregular, glo- SToMATA.-Abundant; triangular; 2 stomata1 bose, variable (Plate 5a,d). bands/intercostal zone, 3 or 4 rows/band: sto- PRIcKLEs.-Common; intercostal prickles; matal bands adjacent to veins and separated by prickles on either side of vein as well as in middle wide area of long cells lacking stomata (Plate of intercostal zone (Plate 54. 7a,b). SHORTCELLs.-Costal single, paired or >5/ INTERSTOMATALCELLs.--Kectangular; ends row (often a single silica cell or a pair of short straight to convex; markedly sinuous, interlock- cells alternates with a single papillate long cell); ing, slightly raised. Papillae: None seen (Plate intercostal not seen. Silica Cells: Costal abun- 7c). dant; intercostal not seen. Cork Cells: Costal LONGCELLs.-Rectangular to long, narrow, abundant: intercostal not seen; each cork cell width uniform; markedly sinuous, interlocking, generally has a single small papilla (Plate 5c,d,e). slightly raised. Papillae: None seen (Plate 74. SILICABoDIEs.-costal saddle-shaped; inter- PRICKLES.-None seen. costal not seen (Plate 5d,e). SHORT CELLS.-costal >5/row: intercostal MICROHAIRS.-common; two-celled; basal paired. Silica Cells: Costal and intercostal abun- longer, apical shorter; apex rounded (Plate 5f). dant. Cork Cells: Costal and intercostal abun- MAcROHAIRS.-None Seen. dant (Plate 7d,e). SILICABoDIEs.-costal and intercostal saddle- ADAXIAL shaped (Plate 7ef). MICROHAIRS.-Non~ seen. SToMATA.-Infrequent; shape of subsidiary cell MACROHAIRS.-None seen. indeterminable because of overarching papillae; stomata occur too infrequently to form a definite ADAXIAL distributional pattern (Plate 6a,b). INTERSTOMATALCELLs.-Not applicable. SToMATA.-Infrequent; triangular; distribu- LONGCELLs.-Long, narrow, width uniform; tion indeterminable because stomata too infre- markedly sinuous, interlocking, raised. Papillae: quent (Plate 86). Many, single row or sometimes irregular, globose, INTERSTOMATALCELLs.-Not applicable. variable; sometimes concealed by wax (Plate 64. LONGCELLs.-Rectangular to long, narrow, PRIcKLEs.-Infrequent; intercostal prickles width uniform; markedly sinuous, interlocking, (Plate 6a). slightly raised. Papillae: None seen (Plate 8a). SHORTCELLs.-Costal solitary (or paired?) ; in- PRrcKLEs.-Infrequent; on margins only (Plate tercostal solitary; short cells indistinct because of 8c). wax. Silica Cells: Costal common; intercostal SHORTCELLs.-Costal paired or >j/row; in- abundant. Cork Cells: None seen (?) (this may tercostal paired. Silica Cells: Costal and inter- be because of wax) (Plate 6c,e). costal abundant. Cork Cells: Costal and intercos- SILICABoDIEs.-costal saddle-shaped; inter- tal abundant (Plate 8d,ef). costal saddle-shaped or sometimes approaching SILICABoDIEs.-costal saddle-shaped: inter- figure-eight (Plate 6c,ef). costal saddle-shaped, figure-eight, or intermedi- MICROHAIRS.-None seen. ate between these two shapes (Plate 8d,ef). MACROHAIRS.-NOnC seen. MIcRoHAIRs.-None seen. 18 SMITHSONIAN CONTRIBUTIONS TO BOTANY

MACROHAIRS.-None seen. ADAXIAL SPECIALFEATuRES.-on the costal regions there are large irregularly distributed structures SToMATA.-Common; triangular; 2 or some- (perhaps silicified papillae) (Plate 80). times 3 stomatal bands/intercostal zone, 2 or sometimes 1 or 3 rows/band; occasional scattered solitary stomata (Plate 106). Tribe OLYREAE INTERSTOMATALCELLs.-Rectangular to long, Olyra latifolia Linnaeus narrow, width uniform; ends markedly concave; markedly sinuous, interlocking, flat to slightly PLATES9-10 raised. Papillae: None seen. LONGCELLs.-Rectangular to long, narrow, ABAXIAL width uniform; markedly sinuous, interlocking, STOMATA.-AbUndant; triangular; 2 or some- flat to slightly raised. Papillae: None seen (Plate times 3 stornatal bands/intercostal zone, 5 or 1 Oa,c) . sometimes 3 or 6 rows/band; bands adjacent to PRICKLES.-None seen. veins (Plate 9a,b). SHORTCELLs.-Costal solitary, paired, or >5/ INTERSTOMATALCELLs.-Rectangular to long, row; intercostal solitary or paired. Silica Cells: narrow, width uniform; ends slightly concave; Costal common; intercostal abundant. Cork Cells: markedly sinuous, interlocking, flat to slightly Costal common: intercostal abundant (Plate raised; often walls appear slightly sinuous because lOc,d,ef). of collapsed cells. Papillae: Many, irregular, glo- SILICABoDIEs.-costal cross-shaped to inter- bose, uniform; other cells lack papillae or papillae mediate between cross-shaped and figure-eight; so deflated as to be inconspicuous (Plate 96). intercostal crenate-vertical (Plate 10d,e). LONGCELLs.-Rectangular to long, narrow, MIcRoHAIRs.-None seen. width uniform; markedly sinuous, interlocking, MACROHAIRS.-None seen. flat to slightly raised; often walls appear slightly sinuous because of collapsed cells. Papillae: Many, Tribe PHAREAE long cells near the stornatal bands often with a single row of small globose uniform papillae; Leptaspis cochlea ta Thwaites sometimes irregular; other long cells usually lack- PLATES11-12 ing papillae; a band of long cells in center of intercostal zone (between stornatal bands) often ABAXIAL has longitudinal folds due to collapsed cells (Plate 9a,c,ej. SToMATA.-Infrequent; high-or sometimes low- PRICKLE^. -None seen. dome; stomata too infrequent to form a distri- SHORTCELLs.-costal >5/row; intercostal butional pattern (Plate 1 lc,dj. paired or sometimes solitary. Silica Cells: Costal INTERSTOMATALCELm-Long, narrow, width and intercostal abundant. Cork Cells: Costal and uniform; ends straight to convex; markedly sin- intercostal abundant (Plate 9d,e). uous, interlocking, raised. Papillae: None seen SILICABoDIEs.-costal cross-shaped to figure- (Plate 1 Id). eight: intercostal crenate-vertical or sometimes LONGCELLs.-Long, narrow, width uniform, figure-eight (Plate 9c,d,e j. sometimes tapered at end; intercostal zone of MIcRoHAIRs.-Abundant; two-celled: basal large veins with narrow band of markedly sin- slightly longer, apical shorter; apex rounded uous, interlocking, raised long cells, alternating (Plate 96f). with narrow bands (small veins?) of slightly sin- MACROHAIRS.-None seen. uous long cells. A single row of short cells occurs NUMBER 49 19 within the latter band. Papillae: None seen Tribe STREPTOGYNEAE (Plate 116). PRICKLES. -None seen. Streptogyna crinita P. Beauvois SHORTCELLS.-costal >5/row; intercostal not PLATES13- 14 seen. Silica Cells: Costal common; intercostal not seen. Cork Cells: Costal common; intercostal not ABAXIAL seen. Throughout the intercostal zone of large veins single rows of short cells (small veins?) occur SToMATA.-Abundant; triangular or some- (Plate lle). times high-dome; 1 stornatal band/intercostal SILICA BODIES.-cOstal dumbbell, ends zone, 3 or sometimes 2-5 rows/band; a small rounded, middle wide or sometimes narrow, short protrusion resembling an underdeveloped papilla (Plate 1 lef). present on each end of subsidiary cell (Plate MIcRoHAIRs.-None seen. 13a,b). MA~RoHAIR~.-None seen. INTERSTOMATALCELLs.-Square to rectangu- lar; ends slightly to markedly concave; markedly sinuous, interlocking, slightly raised. Papillae: ADAXIAL None seen (Plate 13c). LONGCELLs.-Long, narrow, width uniform or SToMATA.-Common; high-or sometimes low- sometimes rectangular; markedly sinuous, inter- dome; 2 stornatal bands/intercostal zone, 2 rows/ locking, slightly raised. Papillae: None seen band, bands adjacent to veins. Each cell adjacent (Plate 13a). to stoma obscured by large deflated papilla (Plate PRIcKLEs.-Infrequent to abundant (varies 12a,b,e). from one specimen to another); costal prickles INTERSTOMATALCELLs.-Each obscured by a (Plate 13e). single large deflated papilla (Plate 126). SHORTCELrs.-Costal solitary, paired or some- LONGCELLs-Long, narrow, width uniform, times 3-5/row or >5/row; intercostal paired. Sil- ends often tapered; slightly sinuous. Papillae: ica Cells: Costal and intercostal abundant. Cork None seen, except cells adjacent to stomata as Cells: Costal and intercostal abundant (Plate indicated above. Intercostal zone of large veins 13c,df). with narrow band of slightly sinuous long cells SILICABoDIEs.-costal and intercostal saddle- alternating with narrow bands (small veins?) of shaped (Plate 13c,df). nonsinuous long cells. A single row of short cells MICROHAIRS.-None seen. occurs within the latter band. Longitudinal stria- MA~R~HAIR~.-None seen. tions often present (Plate 12cf). SPECIALFEATURES.-Transverse veins present. PRIcKLEs.-Infrequent, costal prickles (Plate 12e). ADAXIAL SHORTCELLs.-Costal >5/row; intercostal not seen. Silica Cells: Costal common; intercostal not SToMATA.-common to abundant; triangular; seen. Cork Cells: Costal common; intercostal not 1 stornatal band/intercostal zone, 1 or 2 rows/ seen. In the intercostal zone between major veins, band (Plate 14a,b). single rows of short cells (small veins?) occur INTERSTOMATALCELLs.-Rectangular; ends (Plate 12c,e). slightly concave; slightly sinuous, interlocking, SILICA BoDIEs.-costal dumbbell, ends slightly raised. Papillae: None seen (Plate 14c). rounded, middle narrow or sometimes wide, LONGCELLs.-Long, narrow, width uniform; short; intercostal not seen (Plate 124. markedly sinuous, interlocking, slightly raised. MIcRoHAIRs.-None seen. Papillae: None seen (Plate 14a). MACROHAIRS.-None seen. PRICKLES.-None seen. 20 SMITHSONIAN CONTRIBUTIONS TO BOTANY

SHORT CELLs.-Costal >5/row; intercostal apical slightly longer; apex rounded (usually de- paired. Silica Cells: Costal and intercostal abun- flated) (Plate 15f). dant. Cork Cells: Costal and intercostal abun- MACROHAIRS.-None seen. dant (Plate 14d,e). SILICABODIES.-cOStal and intercostal saddle- ADAXIAL shaped (Plate 14d,e). SToMATA.-Abundant; triangular; 2 stornatal MICROHAIRS.-None seen. bands/intercostal zone, 1 row/band; each subsid- MAcRoHAms.-Infrequent; costal and intercos- iary cell has a pair of papillae (Plate 16a,b). tall basal cells slightly raised (Plate 14f). INTERSTOMATALCELLs.-Square to rectangu- SPECIAL FEATURES.-hrge PrOtrUSiOnS Occur- lar; ends markedly concave; wax obscures outline ring in a row in the midintercostal region (may of cell walls. Papillae: Many, irregular, globose, be silicified papillae) (Plate 14a). uniform (Plate 166 j, LONGCELLs.-Long, narrow, width uniform; Tribe ORYZEAE wax obscures outline of cell walls. Papillae: Leersia hexandra Swartz Many, irregular, globose, uniform (Plate 16c). PRIcKLEs.-Common; costal prickles; intercos- PLATES15-16 tal hooks; hooks usually with a ring of papillae ABAXIAL around base (Plate 16c,d). SHORTCELLS.-costal >5/row; intercostal not STOMATA.-COmmOn; triangular; 2 stomatal seen. Silica Cells: Costal abundant; intercostal bands/intercostal zone, 1 row/band; each subsid- infrequent. Cork Cells: Costal abundant; inter- iary cell has a pair of papillae (Plate 15a,6). costal not seen (Plate 16e). INTERSTOMATALCELLS.-Rectangular; ends SILICABoDIEs.-costal figure-eight or some- markedly or sometimes slightly concave; outline times cross-shaped; intercostal cross-shaped of walls obscured by wax. Papillae: Many, irreg- (Plate 16e j. ular, globose, variable (Plate 156). MICROHAIRS.-common; two-celled; basal cell LONGCELm-Long, narrow, width uniform; slightly shorter than the apical; nature of apex outline of walls obscured by wax. Papillae: indeterminable because of deflated apical cell Many, irregular to occurring in 1 or 2 rows, (Plate 16f). globose, variable. In the midregion of the inter- MACROHAIRS.-None seen. costal zone, on either side of a groove, there are several rows of long cells with very large papillae Ma1 tebr unia leersioides Kunth (Plate 1 ja,c). PRIcKLEs.-Common; costal prickles. Prickles PLATES17- 18 are very large and robust; often the pointed tip is ABAXIAL broken off, prickle then resembles a large papilla (Plate 15d). STOMATA.-Abundant; high-dome; 1 stornatal SHORTCELLs.-costal >5/row; intercostal not band/intercostal zone, 1 or sometimes 2 rows/ seen. Silica Cells: Costal abundant; intercostal band; each subsidiary cell has a pair of papillae, not seen. Cork Cells: Costal abundant; intercos- one at each end of cell (Plate 17a,b). tal not seen (Plate 15e). INTERSTOMATALCELLs.-Square; ends slightly SILICABoDIEs.-costal figure-eight or some- concave although sometimes obscured by pa- times cross-shaped; intercostal not seen (Plate pillae; outline of walls indeterminable. Papillae: 15). Many, irregular, globose, variable; some papillae MIcRoHAms.-Common; two-celled; basal and appear compound or doubled (the forked type of apical equal in length, medium or sometimes Terrell and Wergin, 1979) (Plate 176). NUMBER 49 21

LONGCELLs.-Long, narrow, width uniform or apical slightly longer; nature of apex indetermin- sometimes rectangular; outline of walls indeter- able because of deflated cells (Plate 18f). minable. Papillae: Many, irregular, globose, var- MACROHAIRS.-None Seen. iable; some papillae appear compound or dou- bled (the forked type of Terrell and Wergin, 1979) Oryza punctata Steudel (Plate 17f). PRIcKLEs.-Abundant; costal and intercostal PLATES 19-20 prickles; intercostal hooks (Plate 17e). SHORTCELLS.-costal >5/row; intercostal sol- ABAXIAL itary. Silica Cells: Costal and intercostal abun- SToMArA.-Abundant; triangular; 2 stornatal dant. Cork Cells: Costal abundant; intercostal banddintercostal zone, 2 or sometimes 1 row/ not seen (Plate 1764). SILICABoDIEs.-costal and intercostal figure- band; pair of papillae on each subsidiary cell eight (Plate 17c,d). (Plate 19a,b,d). MIcRoHAIRs.-Abundant; two-celled; basal INTERSTOMATALCELLs.-Square to rectangular or sometimes long, narrow, width uniform; ends and apical equal in length, long; apex indeter- slightly to markedly concave; outline minable because of deflated cells (Plate 17f). of walls obscured by wax. Papillae: Many, irregular or MACROHAIRS-None seen. sometimes in rows, globose to elongate, variable (Plate 196,d). ADAXIAL LONGCELLs.-Long, narrow, width uniform; outline of walls obscured by wax. Papillae: SToMATA.-Abundant; high-dome; 1 stornatal Many, irregular to sometimes in one or two rows, band/intercostal zone, 1 or sometimes 2 rows/ globose to elongate, variable (Plate 196,c,d), band; each subsidiary cell has a pair of papillae, PRIcKLEs.-Abundant; costal prickles (Plate one on each end of cell (Plate 18a,b). 19c). INTERSTOMATALCELLs.-Square; ends slightly SHORTCELLS.-costal >5/row; intercostal sol- concave; outline of walls indeterminable. Papillae: itary. Silica Cells: Costal abundant; intercostal Many, irregular, globose, variable; there seem to common. Cork Cells: Costal abundant; intercos- be fewer papillae than on abaxial, and the pa- tal not seen (Plate 19d,e). pillae are the simple type (Plate 186). SILICABoDIEs.-costal figure-eight; intercostal LONGCELLs.-Long, narrow, width uniform; figure-eight or sometimes crenate-vertical or outline of walls indeterminable. Papillae: Many, cross-shaped (Plate 19d,e). irregular, globose, variable; some long cells fairly MICROHAIRS.-common; two-celled; basal smooth without papillae. Papillae of the simple longer, apical shorter, apex rounded (apical cell type (Plate 18a,e). usually deflated) (Plate 19f). PRIcKLEs.-Common; costal prickles and an MACROHAIRS-None seen. occasional intercostal prickle (Plate 18e). SHORTCELLS.-Costal >5/row; intercostal sol- ADAXIAL itary. Silica Cells: Costal abundant; intercostal common. Cork Cells: Costal abundant; intercos- SToMATA.-Abundant; triangular; 2 stornatal tal not seen (Plate 18c,d). bands/intercostal zone, 1 or sometimes 2 rows/ SILICABoDIEs.-costal figure-eight; intercostal band; pair of papillae on each subsidiary cell figure-eight or sometimes elongated cross-shaped (Plate 20a,b). (Plate 18c,d). INTERSTOMATALCELLs.-Rectangular or some- MIcRoHAIRs.-common; two-celled; basal and times square or long, narrow, width uniform; apical cells equal in length, long, or sometimes ends slightly to markedly concave; outline of 22 SMITHSONIAN CONTRIBUTIONS TO BOTANY walls obscured by wax. Papillae: Many, irregu- Costal and intercostal abundant. Cork Cells: lar or sometimes in rows, globose to elongate, Costal and intercostal abundant (Plate 2 lc,d). variable (Plate 206). SILICABoDIEs.-costal saddle-shaped or some- LONGCELLs.-Long, narrow, width uniform; times figure-eight; intercostal figure-eight (Plate outline of walls obscured by wax. Papillae: 21c,d). Many, irregular or sometimes in rows, globose to MIcRoHAIRs.-Abundant; two-celled; basal elongate, variable (Plate 206,~). shorter, apical slightly longer; apex rounded PRIcKLEs.-Abundant; costal prickles (Plate (Plate 2 If). 20c). MACROHAIRS.-Infrequent; basal cells slightly SHORTCELLs.-Costal >5/row; intercostal sol- raised; margins only (Plate 21e). itary. Silica Cells: Costal abundant; intercostal common. Cork Cells: Costal abundant; intercos- ADAXIAL tal not seen (Plate 20d,e). SILICABoDIEs.-costal figure-eight ; intercostal SToMATA.-Infrequent; triangular; stomata too figure-eight or sometimes cross-shaped (Plate infrequent to form a distributional pattern (Plate 20d,e). 226). MIcRoHAIRs.-common; two-celled; basal INTERSTOMATALCELLs.-Not applicable. longer, apical shorter; apex indeterminable be- LONGCELLs.-Rectangular to long, narrow, cause of deflated apical cells (Plate 20f). width uniform; markedly sinuous, interlocking, MACROHAIRS.-NOne Seen. flat or sometimes slightly raised. Papillae: None seen (Plate 22~4). PRICKLES.-None seen. Tribe PHYLLORHACHIDEXE SHORTCELLs.-Costal solitary, paired, or >5/ row; intercostal paired. Silica Cells: Costal and Humbertochloa greenwayi C. E. Hubbard intercostal abundant. Cork Cells: Costal and in- PLATES21-22 tercostal abundant (Plate 22c,d,e). SILICABoDIEs.-costal and intercostal saddle- shaped and figure-eight (Plate 22c,d,e). ABAXIAL MICROHAIRS.-None seen. STOMATA.-AbUndant; triangular; 2 stornatal MACROHAIRS.-Infrequent; marginal only, bands/intercostal zone, 3 or sometimes 2 rows/ basal cells absent (Plate 22f). band; bands near veins, wide space between bands (Plate 2 la$). Phyllorhachis sagittata Trimen INTERSTOMATALCELLs.-Square to rectangu- lar; ends markedly concave; markedly sinuous, PLATES23-24 interlocking, flat or sometimes slightly raised. Papillae: None seen (Plate 216). ABAXIAL LONGCELLs.-Long, narrow, width uniform; markedly sinuous, interlocking, flat or sometimes STOMATA.-Abundant; triangular; 1 stornatal slightly raised. Papillae: None seen (Plate 21a). band/intercostal zone, 2 or sometimes 1 row/ PRIcKLEs.-Infrequent; margins only, prickles band (Plate 23a,b,c). (Plate 21e). INTERSTOMATALCELLs.-Rectangular to long, SHORTCELLs.-Costal solitary, paired, 3-5/ narrow, width uniform; ends slightly or some- row, or >!)/row; intercostal paired. Silica Cells: times markedly concave; markedly sinuous, inter- NUMBER 49 23 locking, flat or sometimes slightly raised. Papillae: Tribe EHRHARTEAE None seen (Plate 236). LONGCELLs.-Rectangular to long, narrow, Ehrharta erecta (Lamarck) var. abyssinica width uniform; markedly sinuous, interlocking, (Hochstetter) Pilger flat or sometimes slightly raised. Papillae: None seen (Plate 236). PLATES25-26 PRICKLES.-NOne Seen. SHORTCELLs.-Costal solitary or paired; inter- ABAXIAL costal solitary. Silica Cells: Costal and intercostal abundant. Cork Cells: Costal abundant; inter- SToMATA.-Common or sometimes infrequent; low-dome (often collapsed) ; 2 stomatal bands/ costal not seen (Plate 23d,e). intercostal zone, 1 row/band (Plate 25a,b). SILICABODIES.-cOStal cross-shaped; intercos- INTERSTOMATALCELLs.-Rectangular to long, tal crescent-shaped or sometimes tall and narrow narrow, width uniform (often collapsed); ends or figure-eight (Plate 2344. straight to convex or slightly concave, nonsin- MIcRoHAIRs.-Abundant; two-celled; basal uous. Papillae: None seen (Plate 256). shorter, apical longer; apex rounded (often de- LONGCELLs.-Long, narrow, width nonuni- flated) (Plate 23f). form (may be an artifact due to collapse of cell) MACROHAIRS.-NOne Seen. or sometimes uniform near margin; nonsinuous or sometimes slightly sinuous near margin. Pa- ADAXIAL pillae: None seen (Plate 25af). PRIcKLEs.-Common; costal prickles (Plate SToMATA.-Common; triangular; 1 or some- 25c,ef). times 2 stomatal bands/intercostal zone, 1 row/ SHORTCELLs.-costal 3-5 or >5/row; inter- band (Plate 24a). costal not seen. Silica Cells: Costal abundant; INTERSTOMATALCELLs.-Rectangular to long, intercostal not seen. Cork Cells: Costal and inter- narrow, width uniform; ends slightly concave; costal not seen (silica cells appear to be in rows without alternating cork cells) (Plate 254). markedly sinuous, interlocking, flat or sometimes SILICABoDIEs.-costal dumbbell, ends con- slightly raised. Papillae: None seen (Plate 24a). cave, middle narrow, short (often appearing sad- LONGCELLs.-Rectangular to long, narrow, dle-shaped because of indistinct middle portion) ; width uniform; markedly sinuous, interlocking, intercostal not seen (Plate 25c,d). flat or sometimes slightly raised. Papillae: None MICROHAIRS.-InfreqUent; two-celled; basal seen. shorter, apical longer; apex rounded to tapered PRIcKLEs.-Infrequent, marginal prickles (usually collapsed) (Plate 25e, arrow). (Plate 24e). MAcRoHAIRs.-Infrequent; costal, near margin SHORTCELLs.-costal solitary, 3-5/row, or only; basal cells slightly raised or absent (Plate >5/row; intercostal solitary. Silica cells: Costal 25f). and intercostal common. Cork Cells: Costal com- mon; intercostal not seen (Plate 246,c,d). ADAXIAL SILICABODIES.-cOStal cross-shaped or some- times saddle-shaped; intercostal tall and narrow, STOMATA.-cOmmOn; low-dome (often COl- saddle-shaped, or crescent-shaped (Plate 246,c,d). lapsed); 2 or 3 stomatal bands/intercostal zone, MICROHAIRS.-cOmmOn; two-celled; basal 1-3 rows/band (Plate 26a). shorter, apical longer; apex rounded (Plate 248. INTERSTOMATALCELLS.-sqUare to rectangu- MACROHAIRS.-NOne Seen. lar, sometimes long, narrow, width uniform; ends 24 SMITHSONIAN CONTRIBUTIONS TO BOTANY straight to convex; nonsinuous (often collapsed), PRIcKLEs.-Infrequent; intercostal hooks, mar- Papillae: None seen (Plate 26a). ginal prickles (Plate 27e). LONGCELLs.-Rectangular to long, narrow, SHORTCELLs.-Costal >5/row, paired; inter- width uniform to nonuniform; nonsinuous (often costal solitary. Silica Cells: Costal abundant; in- collapsed). Papillae: None seen (Plate 26a,c), tercostal infrequent to common. Cork Cells: Cos- PRIcKLEs.-Common; costal prickles, or costal tal abundant; intercostal not seen (Plate 27c,d). prickles and intercostal prickle-type structures SILICABoDIEs.-costal and intercostal saddle- ranging from prickles to short macrohairs (see shaped (Plate 27c,d). “Macrohairs” below) (Plate 26ef). MrcRoHAIRs.-Infrequent to common; two- SHORTCELLS.-costal >.!)/row; intercostal not celled; basal longer, apical shorter; apex rounded; seen. Silica Cells: Costal abundant; intercostal basal 5 to 6 times as long as apical (Plate 27f). MACROHAIRS.-None seen. not seen. Cork Cells: Costal and intercostal not seen (Plate 26c). ADAXIAL SILICABoDIEs.-costal dumbbell, ends con- SToMATA.-Abundant; shape indeterminable cave, middle narrow, short (often appearing sad- because of wax; 1 band/intercostal zone, 16-18 dle-shaped because of indistinct middle portion) ; rows/band; stornatal band covers entire intercos- intercostal not seen (Plate 266). tal zone (Plate 28a,6). MICROHAIRS.-Infrequent to common; two- INTERSTOMATALCELLs.-Square to rectangu- celled; basal shorter, apical longer; apex tapered lar; ends and outline of walls obscured by wax. (Plate 26d). Pupillae: None seen (Plate 286). MACROHAIRS.-Infrequent; restricted to mar- LONGCELLs.-Rectangular to long, narrow, gin or restricted to costal and marginal areas; width uniform; outline of walls obscured by wax. basal cells slightly raised (occasional “macro-pric- Papillae: None seen. Long cells seem to occur in kles,” somewhat intermediate between prickle 1 or 2 rows (alternating with silica cells) adjacent and macrohair, in intercostal zone) (Plate 26ef). to veins (Plate 28a). PRIcKLEs.-Common; costal prickles; intercos- Tribe ARUNDINEAE tal hooks infrequent along sides of veins (Plate 286). Phragmites mauritianus Kunth SHORTCELLs.-Costal and intercostal paired (?). Silica Cells: Costal and intercostal infrequent PLATES27-28 to common. Cork Cells: Costal and intercostal infrequent to common (Plate 28e). ABAXIAL SILICABODIES.-cOStal and intercostal saddle- shaped (Plate 28e). STOMATA.-Abundant; shape indeterminable MIcRoHAms.-Infrequent; two-celled; basal because of curly wax deposits; 2 bands/intercostal longer, apical shorter; apex rounded; basal 4 to zone, 3-6 rows/band (Plate 27a,b). 5 times as long as apical (Plate 28f). INTERSTOMATALCELLs.-Square to rectangu- MACROHAIRS.-None seen. lar; ends and outline of walls obscured by wax. Papillae: None seen (Plate 276). Tribe DANTHONIEAE LONG CELLs.-Square, rectangular to long, narrow, width uniform; outline of walls obscured Asthenatherum glaucurn (Nees) Nevski by wax. Papillae: None seen. A double row of PLATES29-30 square to rectangular long cells in middle of ABAXIAL intercostal zone; long cells adjacent to veins long, narrow, width uniform, alternating with silica SToMATA.-Common; low-dome to triangular; cells (Plate 27a,d). 1 stornatal band/intercostal zone, 2 or 3 rows/ NUMBER 49 25 band; often in grooves and somewhat obscured common, intercostal not seen. Cork Cells: Costal by overarching prickles (Plate 29a,6). common, intercostal not seen (Plate 30e). INTERSTOMATALCELLs.-Rectangular to long, SILICABoDIEs.-~ostal cross-shaped, square, or narrow, width uniform; ends slightly concave; dumbbell, ends rounded, middle wide and short; markedly sinuous, interlocking, slightly raised. intercostal not seen (Plate 30e). Papillae: None seen (Plate 29a,b). MIcRoHAIRs.-Infrequent; two-celled; basal LONGCELLs.-Long, narrow, width uniform; longer, apical shorter; apex rounded (Plate 30f). markedly sinuous, interlocking, slightly raised. MACROHAIRS.-None seen. Papillae: None seen (Plate 29af). PRIcKLEs.-Abundant; costal prickles, short, Crinipes abyssinicus Hochstetter stiff, macrohair-like prickles; sometimes intercos- tal, short, stiff, macrohair-like prickles; prickles PLATES31-32 often overarching the intercostal zone and ob- scuring features there (Plate 29c,e). ABAXIAL SHORTCELLs.-Costal paired or 3-5/row; in- SToMATA.-Infrequent; low-dome (?), subsidi- tercostal not seen. Silica Cells: Costal common; ary cell collapsed and shape difficult to deter- intercostal not seen. Cork Cells: Costal common; mine; stomata too infrequent to determine distri- intercostal not seen (Plate 29d). butional pattern (Plate 31a). SILICABoDIEs.-~ostal cross-shaped, square, or INTERSTOMATALCELLs.-Not applicable. sometimes elliptical or dumbbell, ends rounded, LONGCELLs.-Long, narrow, width uniform; middle wide and short; intercostal not seen (Plate markedly sinuous, interlocking, raised. Papillae: 29d). None seen. Surface striated; end walls raised MIcRoHAIRs.-Infrequent; two-celled; basal forming a transverse ridge, central portion raised longer, apical shorter; apex rounded (?), usually forming a longitudinal ridge (Plate 314. deflated (Plate 29f). PRICKLES.-None seen. MACROHAIRS.---Noneseen. SHORTCELLs.-costal >5/row; intercostal sol- itary. Silica Cells: Costal abundant; intercostal ADAXIAL not seen. Cork Cells: Costal and intercostal abun- dant (Plate 3 lc,d) . SToMATA.-Common; low-dome to triangular; SILICABoDIEs.-~ostal nodular with 3 or 4 2 stornatal bands/intercostal zone, 1 row/band; nodes; intercostal not seen (Plate 31c). often in grooves, overarched by prickles (Plate MICROHAIRS.-Infrequent; two-celled; basal 30a,b). longer, apical shorter; apex rounded (Plate 3 If). INTERSTOMATALCELLs.-Rectangular to long, MACROHAIRS.-None seen. narrow, width uniform; ends slightly concave; outline of walls indeterminable. Papillae: None ADAXIAL seen (Plate 306). LONGCELLs.-Long, narrow, width uniform; STOMATA.-Abundant; high-dome; 2 stomatal outline of walls indeterminable. Papillae: None banddintercostal zone, 2 or 3 rows/band; bands seen (Plate 30c). adjacent to veins with broad intercostal area PRIcKLEs.-Abundant; costal prickles, hooks, without stomata (Plate 32a,b). and short, straight, stiff, macrohair-like prickles; INTERSTOMATALCELLs.-Rectangular or some- sometimes intercostal hooks and macrohair-like times square; ends slightly concave; outline of prickles (Plate 30c,d). walls indeterminable. Papillae: None seen, sur- SHORTCELLs.-Costal paired, 3-5/row, or >5/ face striated (Plate 32a,b). row; intercostal not seen. Silica Cells: Costal LONGCELLs.-Long, narrow, width uniform, 26 SMITHSONIAN CONTRIBUTIONS TO BOTANY or rectangular, pentagonal, or sometimes square ADAXIAL or hexagonal; outline of walls indeterminable. Papillae: None seen. Surface striated; edges of STOMATA.-cOmmOn; low-dome; 2 stomata1 cells raised to form prominent ridges (Plate 32c,e). bands/intercostal zone, 3-4 rows/band; bands PRIcKLEs.-Common; costal prickles (Plate adjacent to veins with broad region of long cells 324. in between (Plate 34a). SHORTCELLs.-Costal >5/row; intercostal not INTERSTOMATALCELLS. -Long, narrow, width seen. Silica Cells: Costal abundant; intercostal appearing nonuniform (may be an artifact caused not seen. Cork Cells: Costal abundant; intercos- by collapsed cells) ; ends slightly concave; nonsin- tal not seen (Plate 32c). uous. Papillae: Many tiny papillae giving sur- SILICABoDIEs.-~ostal nodular, nodes 4 or face a warty texture; warty texture often obscured sometimes 3; intercostal not seen (Plate 326). by wax (Plate 346,~). M1cRoHAms.-Infrequent; two-celled; basal LONGCELLs.-Rectangular to long, narrow, shorter, apical longer; apex rounded (Plate 32f). width nonuniform (perhaps due to collapsed MACROHAIRS.-hfreqUent; intercostal; basal cells); nonsinuous. Papillae: Many tiny papillae cells markedly raised (Plate 32d). giving surface a warty texture (Plate 3464. PRrcKLEs.-Common; costal prickles; intercos- tal not seen (Plate 3464). Elytroph orus glob ularis Hackel SHORTCELLs.-costal >5/row; intercostal not seen. Silica Cells: Costal abundant; intercostal PLATES33-34 not seen. Cork Cells: Costal abundant; intercos- tal not seen (Plate 34e). ABAXIAL SILICABoDIEs.-costal nodular; intercostal not SToMATA.-Abundant; low-dome; 1-2 stoma- seen (Plate 34e). tal bands/intercostal zone, 1-4 rows/band; sto- MIcRoHAiRs.-Infrequent; two-celled; basal mata often difficult to see because of collapsed shorter, apical much longer; apex tapered (Plate cells (Plate 33a). 34f). INTERSTOMATALCELLs.-Long, narrow, width MACROHAIRS.-None seen. uniform; ends markedly concave; nonsinuous. Pa- Elytrophorus spicatus (Willdenow) A. Camus pillae: Many tiny papillae giving the surface a shows remarkable similarity to this species, the warty appearance (Plate 33a-c). major difference being the apparent absence of LONGCELLs.-Long, narrow, width uniform; the tiny papillae giving the surface a smooth nonsinuous. Papillae: Many tiny papillae giving rather than warty texture. The specimen observed surface a warty appearance (Plate 334. was very waxy, and the wax may obscure the PRIcKLEs.-Infrequent; primarily marginal papillae. (Plate 336). SHORTCELLS.-coSta1 >5/row; intercostal not Habrochloa bullockii Hubbard seen. Silica Cells: Costal abundant; intercostal not seen. Cork Cells: Costal abundant; intercos- PLATES35-36 tal not seen (Plate 33c,e). SILICABODIES.-cOStal nodular; intercostal not ABAXIAL seen (Plate 33c,e). MIcRoHAIRs.-~ommon; two-celled; basal STOMATA.-NOne Seen. shorter, apical much longer; apex tapered LONGCELLs.-Long, narrow, width uniform; (Plate33eJ). slightly sinuous. Papillae: None seen (Plate MA~R~HAIR~.-None Seen. 3546). NUMBER 49 27

PRIcKLEs.-Infrequent to common; costal pric- INTERSTOMATALCELLs.-Rectangular to long, kles (Plate 35a,c). narrow, width uniform; ends slightly concave; SHORTCELLs.-costal >5/row; intercostal not outline of walls obscured by wax. Papillae: None seen. Silica Cells: Costal abundant; intercostal seen (Plate 37c). not seen. Cork Cells: Costal abundant; intercos- LONGCELLs.-Long, narrow, width uniform; tal not seen (Plate 354e). outline of walls obscured by wax. Papillae: None SILICA BoDIEs.-costal dumbbell, ends seen (Plate 374. rounded, middle narrow, long or sometimes nod- PRIcKLEs-Cornmon; costal prickles (Plate ular with three lobes; intercostal not seen (Plate 37c). 35d,e). SHORT CELLS.-Costal >!)/row; intercostal MICROHAIRS.-InfreqUent; two-celled; basal paired. Silica Cells: Costal common; intercostal and apical equal in length, medium (Plate 35f). infrequent. Cork Cells: Costal common; intercos- MACROHAIRS.-None Seen. tal infrequent (Plate 37d,e). ADAXIAL SILICABoDIEs.-~ostal saddle-shaped or some- times cross-shaped; intercostal saddle-shaped SToMATA.-Infrequent; high-dome; 3 stornatal (Plate 37d,e). bands/intercostal zone, 1 row/band (Plate 36b,c). MICROHAIRS.-cOmmOn; two-celled; basal INTERSTOMATALCELLs.-Rectangular to long, longer, apical shorter; apex rounded (Plate 37f). narrow, width uniform to nonuniform (cells often MACROHAIRS-None seen. collapsed and difficult to ascertain width); ends straight to convex; nonsinuous. Papillae: None seen (Plate 366,~). ADAXIAL LONGCELLS.-Long, narrow, width uniform to nonuniform (cells often collapsed) ; nonsinuous. STOMATA.-cOmmOn; low-dome, 2 Stomata1 Papillae: None seen (Plate 36c). bands/intercostal zone, 1-2 rows/band (Plate PRIcKLEs.-Common; costal prickles; infre- 38a,b). quent, intercostal bicellular prickles (Plate 36d,e). INTERSTOMATAL CELLS. - Square to rect an gu - SHORTCELLS.-coStal >5/row; intercostal not lar; ends straight to convex or slightly concave; seen. Silica Cells: Costal abundant; intercostal outline of walls obscured by wax. Papillae: None not seen. Cork Cells: Costal abundant; intercos- seen (Plate 38a,b). tal not seen (Plate 36d). LONGCELLs.-Rectangular to long, narrow, SILICABODIES.-cOStal dumbbell, ends con- width uniform; nature of walls obscured by wax. cave, middle wide, long and short; intercostal not Papillae: None seen (Plate 38af). seen (Plate 36e). PRIcKLEs.-Common; costal prickles (Plate MIcRoHAIRs.-~ommon; two-celled; basal and 38c). apical equal in length, medium, or basal shorter, SHORTCELLS.-costal >5/row; intercostal not apical longer (apical often collapsed) ; apex inde- seen. Silica Cells: Costal abundant; intercostal terminable, apical cell collapsed (Plate 36f). not seen. Cork Cells: Costal common; intercostal MACROHAIRS.-NOnC seen. not seen (Plate 38d). SILICA BoDIEs.-costal dumbbell, ends Neyraudia arundinacea (Linnaeus) Henrard rounded or straight, middle wide, short; intercos- PLATES37-38 tal not seen (Plate 38d). MIcRoHAIRs.-~ommon; two-celled; basal ABAXIAL longer, apical shorter; apex rounded (often col- SToMATA.-Abundant; low-dome; 2 stornatal lapsed) (Plate 38e). bands/intercostal zone, 1 or sometimes 2 rows/ MAcRoHAms.-Infrequent; intercostal (Plate band (Plate 37a,b). 38f). 2% SMITHSONIAN CONTRIBUTIONS TO BOTANY

Pentaschistis borussica (K. Schumann) Pilger PRIcKLEs.-Infrequent; costal prickles (Plate 40c). PLATES39-40 SHORTCELLs.-costal 3-5/row or >5/row; in- tercostal paired. Silica Cells: Costal abundant; ABAXIAL intercostal infrequent (near margins only). Cork STOMATA. -None Seen. Cells: Costal abundant; intercostal infrequent LONGCELLs.-Long, narrow, width uniform; (near margins only ) (Plate 4044. markedly sinuous, interlocking, slightly raised. SILICABoDIEs.-costal nodular or dumbbell, Papillae: None seen (Plates 39a,e). ends rounded, middle wide and short; intercostal PRICKLES.-None seen. (margins only) dumbbell, ends rounded, middle SHORTCELLs.-Costal >5/row, paired; inter- wide and short (Plate 40d,e), costal solitary or paired. Silica Cells: Costal MIcRoHAIRs.-Abundant; two-celled; basal abundant; intercostal infrequent. Cork Cells: longer, apical shorter (basal 7 or more times as Costal abundant; intercostal infrequent (Plate long); apex tapered (Plate 40f). 39a,b). MACROHAIRS.-None seen. SILICA BoDIEs.-costal dumbbell, ends The adaxial of P. minor is very similar to P. rounded, middle wide and short, or sometimes borussica except that no intercostal short cells were square or elliptical (Plate 39a-c). seen. The intercostal zone of P. minor has a few MIcRoHArRs.-common; two-celled; basal large, straight, stiff prickles that resemble short longer, apical shorter (basal 7 or more times as macrohairs. long); apex tapered (Plate 39e). MAcRoHAIRs.-Abundant; basal cells mark- Triraphis schinzii Hackel edly raised (Plate 39f). Pentaschistis minor (Ballard and Hubbard) Bal- PLATES4 1-42 lard and Hubbard was also observed, and the features are remarkably similar to P. borussica. ABAXIAL The obvious difference is the common occurrence of paired or solitary short cells in the intercostal SToMATA.-Common; triangular; 1 stomata1 zone (Plate 394. The cells at the base of the band/intercostal zone, 3-4 rows/band; intercos- macrohairs in P. minor are only slightly raised in tal zone very narrow (Plate 41a-c). contrast to the markedly raised cells described INTERSTOMATALCELLs.-Long, narrow, width above. uniform; ends slightly to markedly concave; markedly sinuous, interlocking, raised. Papillae: ADAXIAL None seen (Plate 41c). LONGCELLs.-Long, narrow, width uniform; STOMATA.-COmmOn; low-dome; 1 Stomata1 markedly sinuous, interlocking, raised. Papillae: band/intercostal zone, 1 or 2 rows/band (Plate None seen (Plate 41a). 40a,b). PRICKLES.-None seen. INTERSTOMATALCELLs.-Square to rectangu- SHORT CELLs.-Costal >!)/row; intercostal not lar; ends slightly concave; outline of walls indis- seen. Silica Cells: Costal common; intercostal not tinguishable because of wax. Papillae: None seen seen. Cork Cells: Costal common; intercostal not (Plate 40a). seen (Plate 414. LONGCELLs.-Long, narrow, width uniform or SILICABoDIEs.-costal dumbbell, ends con- sometimes rectangular to pentagonal; markedly cave or sometimes straight, middle wide, short; sinuous, interlocking, slightly raised. Papillae: intercostal not seen (Plate 4 ld,e). None seen (Plate 40bf). MICROHAIRS.-common; two-celled; basal NUMBER 49 29 longer, apical shorter: apex tapered; occur in rows narrow, width uniform; ends slightly concave; on each side of veins (Plate 41f). markedly sinuous, interlocking, raised. Papillae: MACR~HAIRS.-None Seen. Many, irregular, globose, variable, extremely small giving surface a warty texture (Plate 436). ADAXIAL LONGCELLs.-Long, narrow, width uniform: markedly sinuous, interlocking, raised. Papzllae: SToMATA.-Common; triangular (shape some- Many, irregular, globose, variable, extremely times indistinct because of wax); 2 stomatal small giving surface a warty texture (Plate 43a). bands/intercostal zone, 2 or sometimes 1 row/ PRIcKLEs.-Common; intercostal prickles band (Plate 42a,b). (Plate 43a). INTERSTOMATALCELLs.-Rectangular to long, SHORTCELLs.-Costal >j/row; intercostal in- narrow, width uniform; ends slightly concave; frequent (?). Silica Cells: Costal common; inter- slightly to markedly sinuous; outline of walls costal not seen. Cork Cells: Costal common: in- indistinct because of wax. Papillae: None seen tercostal infrequent (?) (Plate 43c). (Plate 42a,c). SILICA BoDIEs.-costal dumbbell, ends LONGCELLs.-Long, narrow, width uniform; rounded or sometimes straight, middle narrow, slightly to markedly sinuous; outline of walls short; intercostal not seen (Plate 43c). indistinct because of wax. Papillae: None seen MIcRoHAIRs.-1nfrequent: two-celled; basal (Plate 42a). shorter, apical longer; apex rounded: demarca- PRIcKms.--Infrequent; costal prickles; com- tion between basal and apical cells usually indis- mon near margins (Plate 42dfi. tinct (Plate 434. SHORTCELLs.-costal >5/row: intercostal not MAcROHAIRs.-1nfrequent; intercostal: basal seen. Silica Cells: Costal abundant; intercostal cells markedly raised (Plate 43e). not seen. Cork Cells: Costal abundant; intercos- SPECIALFEATvREs.-Transverse veins present tal not seen (Plate 42a,c,d). (Plate 43f). SILICABoDIEs.-costal dumbbell, ends con- cave or sometimes straight, middle wide, short or ADAXIAL sometimes long; intercostal not seen (Plate 42c,d). MIcRoHAIRs.-Abundant; two-celled; basal SToMATA.-Infrequent; triangular: 1-2 stoma- longer, apical slightly shorter to basal and apical tal bands/intercostal zone, 1 row/band (Plate equal in length; apex tapered (Plate 42e). 44a). MACR~HAIRS.-None seen. INTERSTOMATALCELLs.-Rectangular to long, narrow, width uniform; ends straight to convex Tribe CENTOSTECEAE or slightly concave; markedly sinuous, interlock- ing, raised. Papillae: Some irregular, globose, Bromuniola gossweileri Stapf and variable, extremely small (surface features less C. E. Hubbard distinct than on abaxial because of wax) (Plate 44a). PLATES43-44 LONGCELLs.-Long, narrow, width uniform or ABAXIAL sometimes rectangular; markedly sinuous, inter- locking, raised. Papillae: Some irregular, glo- SToMATA.-Common; triangular; 2 stomatal bose, variable, extremely small (surface features bands/intercostal zone, 2 rows/band; bands ad- less distinct than on abaxial because of wax) jacent to veins, fairly wide region of long cells (Plate 446,~). between bands (Plate 436). PRIcKLEs.-Common; intercostal prickles and INTERSTOMATALCELLs.-Rectangular to long, hooks (Plate 44a,c). 30 SMITHSONIAN COXTRIBUTIONS TO BOTANY

SHORTCELLs.-costal >5/row; intercostal not ADAXIAL seen. Silica Cells: Costal common; intercostal not seen. Cork Cells: Costal common; intercostal not STOMATA.-Abundant; triangular; 2 or 3 sto- seen (Plate 444. matal bands/intercostal zone, 1 or 2 rows/band; SILICABoDIEs.-costal dumbbell, ends straight bands adjacent to veins (Plate 46a). to concave, middle wide, short (Plate 444. INTERSTOMATALCELLs.-Rec t angular to long, MIcRoHAIRs.-Infrequent; two-celled; basal narrow, width uniform; ends markedly concave; shorter, apical longer; apex rounded; demarca- markedly sinuous, interlocking, raised. Papillae: tion between basal and apical cells usually indis- Many, irregular, globose, variable, extremely tinct (Plate 44e). small giving surface a warty texture (Plate 466). MACROHAIRS.-cOmmOn; intercostal; basal LONGCELLs.-Rectangular to long, narrow, cells markedly raised (Plate 44f). width uniform; markedly sinuous, interlocking, raised or sometimes flat. Papillae: Many, irreg- ular, globose, variable, extremely small giving Megastachya mucronata (Poiret) P. Beauvois surface a warty texture (Plate 46c). PRIcKLEs.-Common; intercostal, appearing PLATES45-46 bicellular (Plate 46d). SHORTCELLs.-Costal >5/row; intercostal sol- ABAXIAL itary (?). Silica Cells: Costal abundant; intercos- tal not seen. Costal abundant; inter- STOMATA.-AbUndant; triangular; 6 or some- Cork Cells: costal common (?) (Plate 46a,e). times 5 stornatal bands/intercostal zone, 2 or SILICA BoDIEs.-costal dumbbell, ends sometimes 1 row/band (Plate 45a,b). IKTERSTOMATALCELLs.-Rectangular or some- straight, middle wide and short; intercostal not times long, narrow, width uniform; ends mark- seen (Plate 46e). edly or sometimes slightly concave; markedly to MICROHAIRS.-Infrequent; two-celled; basal slightly sinuous, interlocking, flat. Papillae: shorter, apical longer; apex rounded (?); basal cell appears to be sunken; apical cell tip often Many, irregular, globose, variable, extremely broken (Plate 46f). small giving surface a warty texture (Plate 45c). LONGCELLs.-Long, narrow, width uniform; MACROHAIRS.-None seen. markedly sinuous, interlocking, flat. Papillae: Many, irregular, globose, variable, extremely Orthoclada africana Hubbard small giving surface a warty texture (Plate 45c). PLATES47-48 PRIcKLEs.-Infrequent; on or near margin only. ABAXIAL SHORTCELLs.-Costal >5/row; intercostal not seen. Silica Cells: Costal abundant; intercostal SToMATA.-Common; triangular; 2 stornatal not seen. Cork Cells: Costal abundant; intercos- bands/intercostal zone, 2 or sometimes 1 or 3 tal not seen (Plate 454. rows/band, an occasional stoma outside rows; SILICABoDIEs.-costal dumbbell, ends straight bands adjacent to veins, wide space between or sometimes concave, middle wide and short; bands (Plate 47a,b). intercostal not seen (Plate 454. INTERSTOMATALCELLs.-Square to rectangu- MICROHAIRS.-cOmmOn; two-celled; basal lar; ends slightly concave; slightly sinuous, inter- shorter, apical longer; apex rounded (Plate 45e). locking, flat. Papillae: Many, irregular, globose, MACROHAIRS.-NOne Seen. variable, extremely small giving surface a warty SPECIALFEATuREs.-Transverse veins present texture (Plate 47a,b). (Plate 45f). LONGCELLs.-Rectangular; slightly sinuous, NUMBER 19 31 interlocking, flat. Papillae: Many, irregular, glo- INTERSTOMATALCELLS.-Rectangular; ends bose, variable, extremely small giving surface a straight to slightly concave; slightly sinuous, in- warty texture (Plate 47d,e). terlocking, flat. Papillae: Many, irregular, glo- PRICKLES.-None seen. bose, variable, extremely small giving surface a SHORTCELLS.-costal >5/row; intercostal sol- warty texture (Plate 48a). itary. Silica Cells: Costal common; intercostal LONGCELLs.-Square to rectangular; slightly infrequent. Cork Cells: Costal common; intercos- sinuous, interlocking, flat. Papillae: Many, irreg- tal not seen (?) (Plate 47c,d). ular, globose, variable, extremely small giving SILICABODIES.-cOStal dumbbell, ends straight surface a warty texture (Plate 486). to concave, middle wide and short; intercostal PRICKLES.-None seen. crenate-vertical, sometimes cross-shaped, figure- SHORTCELLs.-costal >5/row; intercostal not eight, or irregular (Plate 47c,d). MIcRoHAIRs.-Abundant; two-celled; basal seen. Silica Cells: Costal common; intercostal not and apical equal in length, medium, or sometimes seen. Cork Cells: Costal common; intercostal not basal slightly longer than apical, long; apex ta- seen (Plate 48c). pered (Plate 474. SILICABoDIEs.-costal dumbbell, ends straight MAcRoHA1Rs.-Infrequent; intercostal; basal to concave, middle wide and short; intercostal cells slightly raised; macrohairs short; ends curved not seen (Plate 48c). like a fish-hook (Plate 47e). MICROHAIRS.-Infrequent; two-celled; basal SPECIALFEATuREs.-Transverse veins present and apical equal in length, medium; apex tapered (Plate 47f). (Plate 484. MACROHAIRS.-Infrequent; intercostal; basal ADAXIAL cells slightly raised; macrohairs short; ends curved SToMATA.-Infrequent; triangular; too few sto- like a fish-hook (Plate 48e). mata to form a distributional pattern; those few SPECIALFEATURES.-Transverse veins present observed adjacent to veins (Plate 48a). (Plate 48f). Appendix

Material Studied (Ahiterisk indicates taxa treated in this study)

Species Collerliun Origin Herbarurn Andropterum stolzii W’iehe 5/293 Malawi K * Arundinaria alpina Dummer 3.508 Uganda US hleyer 7750 Uganda US Asthenatherum Sorskalii Mandaville 388 Saudi Arabia US * Asthenatherum glaucum Rains & Yalala 22 Botswana K Aiena abJJinica Pappi 4901 Ethiopia u S Brachiaria britanlha Hitchcock 24884 Cganda US * Bromuniola gossawleri Jackson 47 Rhodesia MO Chlorocaiymma cr).torunlha Greenway & Kanuri Tanganyi ka .MO 13980 Chiyoch loa h indsii Lewalle 4841 Burundi M 0 Cleistachne JorghoideJ Thomas 1325 Uganda US Coelachne ajricana Schlieben 4161 Tanganyi ka US Colpodium chionogeiton M‘ood 923 Tanzania K Commelinidium mayumbense Chandler 1859 Uganda US * Crinipes abyssinicus’ Gay s.n. Ethiopia US Cynodon dactylon Hitchcock 24507 Tanganyi ka us Dar!ylis glornerala Gillett 157.53 E. Jordan US Dactyloctenium giganteum Bullock 305 Tanganyi ka US Daknopholis boirinii Croat 30897 Madagascar MO Danthoniopsis ciridis \‘erhoon 1373 Rhodesia CS Dichanthium aristahm Eyles 22 10 Rhodesia MO Echinochloa colona de LVet 5416 Cultivated CEL Echinochloa pyramidalis Ortaggeup 372 Soudan US * Ehrharta erecta var. Renvoize 2099 Tanzania US a b) ssi n i ca Renvoize 2454 Tanzania US Eleusine coracana de LVet 3833 Cu li ivated CEL * Elytrophorus globularis Schweickerdi 2158 Southwest Africa US Elytrophorus spicatus Rensburg 190.5 N. Rhodesia US * Habrochloa bullockii M’ebster T234 Tanganyi ka MO Harpachne srhimperi Milne-Redhead & Tanganyi ka US Taylor 8828 Helictotrichon elongatum Liebenberg 12 Uganda US Heteroanthoecia guineensiJ Simon & M’illiamson Zambia MO 1925 * Humbertochloa greenwali Lyingfield 1680 Tanzania MO Isachne buetlneri Baldwin 67 18 Liberia MO * Leersia hexandru Milne-Redhead ti Tanganyi ka US Taylor 8664

’ Very similar to the East African species C. lvngijvlius Hubbard, which is poorly collected and for which no material was available. 32 NUMBER 49 33

* Leptaspis cochleata Shandler 2890 Uganda 0.S Brenan 8504 Nigeria CJ S Lepturus repens Bogdan 3642 Kenya L.S * Maitebrunia leersioides Humbert 5783 Madagascar I'S * Megastachya mucronata Faden 74/34? Tanzania MO * .Vtyraudia arundinacea Humbert 13042 Madagascar C! S * Olyra iattfolia Baldwin 100.59 Liberia I! S Clayton 623 Nigeria US Faulkner 1201 Tanganyi ka LJ S Hitchcock 24535 Tanganyi ka L: S Palmer 90 1 Ghana DUKE * Oreobambos buchwaidii Thomas 377.5 Uganda K Oropetium thomaeum Olufsen 393 French Sudan I: S * Orthoclada africana Paterson J.n. M w i n i I u n ga Lu a ke r a Ll S Falls, Zambia. Oct. 1937-Feb. 1938 Oryra barthii de Wet 626 C u 1 ti vai ed CEI. de Wet 633 Cultivated CEL * Oiya punctata GreenLvay 13 1.5 1 Tanganyi ka hl0 * Oxytenanthera abyssinica Snowden 105 1 Uganda L' S * Pentaschistis borussica Hitchcock 24629 Tanganyi ka US Pentaschistis minor Hitchcock 24641 Tanganyi ka US Phacelurus huillensis Webster T238 Tanzania K * Phragmites mauritianus Hitchcock 24910 Uganda Ll S Mearns 1211 British E. Africa US * Phyllorhachis sagitatta Guy 1636 Rhodesia .110 * Pueiia olyrijormis Callens 2678 French Congo K Sacciolepis africana Thomas 4.544 Cganda LS Schmidtia bulbosa Brass 17909 Malawi CS Sehima nervosum Hudson 271 Uganda u S Sorghum arundinaceum Myre 26 .Mozambique US Stipa drageana Schweickerdt 1818 S. Africa US * Streptogyna crinita Jones. Reag, & Ono- Nigeria .LI0 chic 14.564 Louis 12181 Zaire K Trichoneura moilis Napper .5.W Kenya US Triraphisfleckii SchLveickerdt 2 115 S.LV. Africa US * Triraphis schinrii Schweickerdt 1859 North Transvaal US Triticum aestivum Harshberger 1 139 Algeria US Cbssia cuspidata Meyer 7503 Ethiopia US Literature Cited

Clark, C. A,, and F. W. Gould Palmer, P. G. 1975. Some Epidermal Characteristics of Paleas of Di- 1976. Grass Cuticles: A New Paleoecological Tool for chanthelium, Panicum, and Echinochloa. American Jour- East African Lake Sediments. Canadian Journal of nal oJBotany, 62(7):743-748. Botany, 54(15): 1725-1734. Clayton, W. D. Prat, H. 1970. Gramineae, Part 1. In E. Milne-Redhead and R. 1932. L’Epiderme des graminees: Etude anatomique et M. Polhill, editors, Flora oJ Tropical Easl AJrica. syseimatique. Annales des Sciences ~Vaturelles.Bota- pages 1 - 176. London: Crown Agents for Oversea nique, series 10, 14: 117-324. Governments and Administrations, 1936. La Syseimatique des Graminees. Annales des Sciences 1974. Gramineae, Part 2. In E. Milne-Redhead and R. Naturelles, Botanique, series 10. 18: 165-258. M. Polhill. editors. Flora 01 Tropical East AJrica. Soderstrom, T. R., and H. F. Decker pages 177-449. London: Crown Agents for Over- 1973. Calderonella, a New Genus of Grasses and Its Re- sea Governments and Administrations. lationships to the Centostecoid Genera. Annals of In prep. Gramineae. Part 3. In E. Milne-Redhead and R. the Missouri Botanical Garden. 60(2):427-441. M. Polhill, editors, Flora of Tropical East Africa. Stewart, D.R.M. London: Crown Agents for Oversea Governments 1965a. The Epidermal Characters of Grasses, with Special and Administrations. Reference to East African Plains Species, Part 1. Jacques-Felix, H. Botanische Jahrbucher, 84(1):63-116. 1962. Les Graminees d’Afrique tropicale, I: GeneralieEs. 1965b. The Epidermal Characters of Grasses, with Special classification, description des genres. Bulletin Scien- Reference to East African Plains Species, Part 2. tifique D’Institut de Kecherches Agronomiques Tropicales Botanische Jahrbucher, 84(2):1 17- 173. et des Cultures Vtvieres, 8: xi + 345 pages. Tateoka, T., S. Inoue, and S. Kawano Livingstone, D. A,, and W. D. Clayton 1959. Notes on Some Grasses, IX: Systematic Signifi- 1980. An Altitudinal Cline in Tropical African Grass cance of Bicellular Microhairs of Leaf Epidermis. Floras and Its Paleoecological Significance. Qua- Botanical Gazette, 121(2):80-91. ternary Research, 13:392-402. Terrell, E. E., and W. P. Wergin Metcalfe, C. R. 1979. Scanning Electron Microscopy and Energy Dis- 1960. Anatomy ofthe Monocotyledons, I: Gramineae. Ixi + 731 persive X-Ray Analysis of Leaf Epidermis in Zi- pages. London: Oxford University Press. rania (Gramineae). Scanning Electron Microscopy, 3: 81-88.

34 Plates 36 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE1.-Abaxial epidermis Arundinarza alpina, Dummer 3508: a, overview, X 416; b, stoma with overarching papillae, X 1696; c, papillate long cells, X 867; d, prickle, X 1696; e, intercostal silica bodies (sb). cork cells (cc) and costal silica body (sb), X 867;J microhair, X 1696. NUMBER 49 37

PLATE2.-Adaxial epidermis ilrundinaria alpina. Dummer 3508: Q. stoma. X 1285: b. overview, interstomatal cell, X 416: c. long cells, X 416: d. intercostal prickles, X 867: e, costal silica bodies (sb) and cork cells (cc), X 867:J intercostal cork cell (cc) and silica body (sb), X 1696. 38 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE3.--.4baxial epidermis Oreobambos buchalaldii, Thomas 3775: a. overview. X 295; b, stomata, interstomatal cell. X 1285. c, costal silica bodies (sb) and cork cells (cc), X 1285; d. intercostal cork cell (cc) and silica body (sb). X 2970: e, microhair. X 867:J, baae of macrohair, X 867. NUMBER 49 39

PLATE4.-Adaxial epidermis Oreobambos buchwaldii, Thomas 377.5: a, overview, X 293: b. stoma. X 867; c, interstomatal cell, X 867; d, long cells (note wide band at arrow), X 116; e. intercostal silica bodies (sb) and cork cells (cc), X 867;J cork cell (cc) and silica body (sb). X 1696. 40 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE 5.-Abaxial epidermis Oglenanlhera abJss'nira, Snowden 105 1 : a, overview, X 416; b, stoma, X 1696; G, interstornatal cell, X 128.5; d, prickles, X 295; e, costal silica bodies (sb) and cork cells (cc), X 867;J microhair, X 1696. NUMBER 49 41

PLATE6.--Adaxial epidermis Oxylenanlheru abq..\.\inica. Snowden 10.5 1 : a, overview. X 295; b, stoma, X 1696: c, long and short cells, X 295: d, long cells. X 867: e. silica bodies (sb). X 62.5: J intercostal silica body. X 1696. 42 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE7.- Abaxial epidermis l’uelia o&r@rrnis. Callens 2678: a, overview. X 295; b, stoma, X 1696; c. interstomatal cells, X 62.5: d, long cells, X 625; e. costal silica bodies (sb) and cork cells (cc), X 867:J intercostal cork cells (cc) and silica bodies (sb), X 1285. NUMBER 49 43

PLATE8.-Adaxial epidermis Puelza o1yrtformzs, Callens 2678. a, overview, X 295; b, stoma, X 1285: c, marginal prickles, X 121: d, costal silica bodies (sb) and cork cells (cc), X 867: e. intercostal silica bodies (sb) and cork cells (cc), X 867; intercostal cork cell (cc) and silica body (sb), X 1696 44 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE9.-Abaxial epidermis O~YUiatfofolza, Hitchcock 24555 (a,b,e), Faulkner 1201 (c,dJ;): a, overview, X 161: b: stomata, X 867; c, stomata1 band, X 295; d, costal silica bodies (sb) and cork cells (cc), X 625: e, intercostal silica bodies (sb) and cork cells (cc), X 625;f,microhair, X 1285. NUMBER 49 45

PLATE10.-Adaxial epidermis Olyra latifolza, Faulkner 1201: a, overview, X 295: b. stoma, X 2970; c, intercostal long and short cells, X 416; d, costal silica bodies (sb) and cork cells (cc). X 1285: e, intercostal silica bodies (sb) and cork cells (cc), X 867:f, intercostal cork cell, X 1285. 46 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE1 1.-Abaxial epidermis Leplaspis cochleala, Shandler 2890: a, overview, X 295; b, banded intercostal zone between large veins, X 416; c, stoma, X 128.5; d, interstomatal cell, X 62.5; e, costal silica bodies (sb) and cork cells (cc), X 867;f, costal silica body, X 4290. NUMBER 49 47

PLATE12.-Adaxial epidermis Leplaspis cochleata, Shandler 2890: a, overview, X 161; 6, stomata with large deflated papillae on adjacent cells, X 1285; c, portion of a banded intercostal zone between large veins, X 625; a', costal silica bodies (sb) and cork cells (cc), X 867; e, costal prickles, X 416;J slightly sinuous long cells with longitudinal striations, X 1696. 48 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE13.-Abaxial epidermis Strepto~nacrznita Jones, Reag, and Onochie 14564 (a-c), Louis 12181 (d-f): a, overview, X 416; b, stoma, X 2970. c, interstomatal cell, X 1285; d, costal silica bodies (sb) and cork cells (cc), X 867; e, costal prickle, X 867,f, intercostal cork cell (cc) and silica body (sb), X 2970. NUMBER 49 49

PLATE14.--Adaxial epidermis Streptogym crznzta, Louis 12181: a. overview, X 29.5: b. stoma. X 2970: c. interstomatal cell, X 1285: d. costal silica bodies (sb) and cork cells (cc). X 867: e, intercostal silica body (sb) and cork cell (cc). X 2970:J base of macrohair. X 625. 50 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE15.-Abaxial epidermis Leersza hexandra. Milne-Redhead and Taylor 8664: a, overview, X 295; b, stomata and interstomatal cell. X 867; c. long cells, X 625; d, costal prickle. X 62.5; e, costal silica bodies (sb) and cork cells (cc). X 1696:,[. microhair. X 1696. NUMBER 49 51

PLATE16.--Adaxial epidermis Leersia hexandra, Milne-Redhead and Taylor 8664: a, overview. X 416; b, stomata and interstornatal cell, X 867; c, costal prickle. long cells, intercostal hooks. X 625: d, intercostal hook with papillate base. X 1696: e. costal silica bodies (sb) and cork cells (cc) and intercostal silica body (sb). X 867:s. rnicrohair. X 1696. SMITHSONIAK CONTRIBLTIOSS TO BOTANY

PLATE 1 i.-Abaxial epidermis ,Waltebrunia leersioides, Humbert 5783: a, overview, X 295; b, stoma with papillate subsidiary cells and inrerstomaral cell. X 1696; c, costal silica bodies (sb) and cork cells (cc). X 1696: d. intercostal silica body. X 2970; e. costal prickles. X 416; f. microhair, X 1285. NUMBER 49 53

PLATE18.-Adaxial epidermis Maltebrunia leersioides, Humbert 5783: a, overview, X 295; b, stoma with papillate subsidiary cells, X 1696; c, costal silica bodies (sb) and cork cells (cc), X 1696; d, intercostal silica body, X 2970; e, costal prickles, X 416;J microhair, X 1285. 54 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE19.-Abaxial epidermis Oiyra punclala, Greenway 151.5 1: a, overview, X 29.5; 6, stomata and interstomatal cell, X 128.5: c: costal prickles: X 625; d, costal silica bodies (sb) and cork cells (cc), X 1285; e, intercostal silica bodies, X 4290:J; microhair, X 128.5. NUMBER 19 55

PLATE20.-Adaxial epidermis Oyapunctata, Greenway 15151: a, overview, X 295; b, stomata and interstomatal cell. X 1285: c, costal prickle, X 625: d, costal silica bodies (sb) and cork cells (cc), X 1285: e, intercostal silica body. X 4290;f, microhair, X 1285. 56 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE2 1 .-Abaxial epidermis Humbertochlvu greenuqi, Wingfield 1680: a, overview, X 295; b, stomata and interstomatal cells, X 867; c, costal silica bodies (sb) and cork cells (cc), X 867; d, intercostal cork cells (cc) and silica bodies (sb), X 1285; e, marginal macrohair and prickles, X 121;J microhair, X 1285. NUMBER 49

PLATE22.-Adaxial epidermis Humbertochloa greenwayi, Wingfield 1680: a, overview. x 295; b, stoma, X 2970; c, costal silica bodies (sb) and cork cells (cc), X 1285; d, intercostal silica bodies (sb) and cork cells (cc), X 867; e, intercostal cork cell (cc) and silica body (sb), X 2970; J marginal macrohairs, X 80. 58 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE23.-Abaxial epidermis I’hyllorhachis sagiltata, Guy 1636: a, o\rerview. X 295: 6, intersto- matal cell, X 625; c, stoma, X 1696: d, costal silica bodies (sb) and cork cells (cc), X 867; e, intercostal silica bodies, X 867;,f, microhair, X 1285. NUMBER 49 59

PLATE24.-Adaxial epidermis I’hyllorhachis sagillala, Guy 1636: a, stomata and interstornatal cell, X 625; b, costal silica bodies (sb) and cork cells (cc), X 867; c, outline of long cells and intercostal silica body (arrow), X 1696; a‘, intercostal silica body, X 1696; e, marginal prickles, X 416;S, microhair, X 1285. 60 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE25.-Abaxial epidermis Ehrharla erecta var. abyssinzca, Renvoize 2099: a, overview, X 295; b, stoma, X 1696; c, costal prickles, X 867; d, costal silica bodies, X 128.5; e, microhair (arrow) and costal prickle, X 867;S, marginal macrohairs and prickles, X 121. NUMBER 49 61

PLATE%-Adaxial epidermis Ehrharta erecta var. abyssmica, Renvoize 2099 (a-c), Renvoize 2454 (e,fl: a, overview, X 416; b, stoma, X 2970: c, ostal silica bodies, X 867: d, microhair, X 1696; e, intercostal short macrohair. X 1696;f. marginal prickles and macrohairs, X 161. 62 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE27.-Abaxial epidermis I’hragmites mauritianus. Hitchcock 24910: a, overview, X 295; b, stomata (arrow), X 128.5: c, costal silica bodies, X 867; d, costal silica bodies (sb) and cork cells (cc), X 867; e, intercostal hook, X 2970:J microhair, X 1696. NUMBER 19 63

PLATE28.-Adaxial epidermis I’hragmiles maurilianus. Hitchcock 249 10: a. overview. X 293: b, stoma, X 2970; c. interstornatal cells, X 867; d. cosial prickle and hooks (arrow), X 1285; e. costal silica bodies, X l696:,/; microhair, X 1696. 64 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE29.-Abaxial epidermis Asthenatherum glaucum, Rains and Yalala 22: u, overview, X 295: b, stoma; X 1285; c, costal macrohair-like prickle, X 867; d, costal cork cells (cc) and silica bodies (sb), X 867; e, overvieL7. X 16l;J microhair, X 867. NUMBER 49 65

PLATE30,-Adaxial epidermis Asthenalherum glancum. Rains and Yalala 22: a. overview. X 161: b, stoma, X 867; c. interstomatal cells. X 416; d. costal macrohair-like prickles, X 128.7: e. costal silica bodies (sb) and cork cells (cc). X 625:J; microhair, X 867. 66 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE31.-.4baxial epidermis Crznipes abjssinicus. Gay s.n.: a. stoma. X 1696; 6, overview. X 293: c. costal silica bodies (sb) and cork cells (cc). X 867: d. intercostal cork cells. X 867: e. long cells, X 625: .f. microhair, X 1285. NUMBER 49 67

PLATE32.-Adaxial epidermis Crmipes abyssinms, Gay s.n.: a? stoma, X 1696; b. overview. X 295; c. costal silica bodies (sb) and cork cells (cc), X 867: d, base of macrohair, X 867: e, long cells. X 867;f, microhair, X 1696. 6% SMITHSONIAN CONTRIBCTIOKS TO BOTANY

PLATE33.-Abaxial epidermis Eblrophorus globularzs, Schweickerdt 2 158: a, stoma, X 1285: b, costal prickle, X 295; c, long cells, X 295: d. papillate warty surface, X 2970; e, costal silica bodies (sb) and cork cells (cc). X 867:J microhair. X 1285. NUMBER 49 69

PLATE31.-Adaxial epidermis Ebtrophorus globularis, Schweickerdt 2 158: a, stomata. X 1285: b, interstomatal cell. X 416: c, long cells, X 295: d, papillate warty surface, X 2970: e, costal silica bodies (sb) and cork cells (cc), X 867;f, microhair. X 1285. 70 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATESj.-Abaxial epidermis Habrochloa bullockii, Webster T234: a, overview, X 295; b. long cells. X 867: c, costal prickle. X 128.7: d, costal silica bodies, X 1285: e, costal silica bodies. X l696:J microhair. X 2970. NUMBER 49 71

PLATESfj-Adaxial epidermis Habrochloa bullockit, kl’ebster T234: a, overview. X 29.5; b. stoma. X 2970: c, long cells, X 867; d, bicellular prickle, X 1696: e. cosial prickles. silica bodies (sb) and cork cells (cc), X 867; J microhairs. X 1696. 72 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE37.-Abaxial epidermis JVeyraudia arundznacea, Humbert 13042: a, overview, X 295: 6, stomata, X 1696: c. costal prickles and interstomatal cell, X 625; d. costal silica bodies (sb) and cork cells (cc). X 867; e, intercostal cork cell (cc) and silica body (sb). X 1696;J microhair, X 1696. NUMBER 49 73

PLATE38.-Adaxial epidermis ?ieyaudia arundinacea, Humberi 13042: a, overview, x 4 16; b, stomata, X 1696; c, costal prickle, X 867; d, costal silica body (sb) and cork cells (cc), x I28.j; e, microhair, X 1696;f. macrohair, X 295. 74 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PL.ATE39.--r\baxial epidermis Pentaschislis borussica. Hitchcock 24629 (a-c, eJ). and abaxial epidermis 1’. minor (Ballard and Hubbard) Ballard and Hubbard. Hitchcock 24641 (4: a. overview. X 29.5: b. costal silica bodies (sb) and cork cells (cc)%X 867: c, long cells. X 295: d, intercostal silica body (sb) and cork cell (cc). X 1696: e, microhair, X 867:s. macrohair base. X 867. NUMBER 49 75

PLATE40.-Adaxial epidermis Penlaschisfis borusszca, Hitchcock 24629: a, stomata and intersto- matal cell, X 867; b, overview, X 29.5: c, costal prickle, X 867: d. costal silica bodies (sb) and cork cells (cc). X 867; e. marginal area, X 625:s. microhair. X 867. 76 SMITHSONIAS CONTRIBUTIONS TO BOTANY

PLATE4 1 .--.L\baxial epidermis Triraphis schznzii, Schweickerdt 1859: Q; overview. X 295; b. stoma, X 2970; c, interstomatal cell, X 625: d: costal silica bodies (sb) and cork cells (cc), X 625: e. costal silica body (partially obscured by wax), X 2970:J microhair, X 1285. NUMBER 49 77

PLATE42.-Adaxial epidermis Trzraphis schintii, Schweickerdt 1859: a, overview. X 295; b. stoma, X 1696; c, interstomatal cell, X 867; d, costal silica bodies (sb). cork cells (cc). and prickle. X 867: e, microhair, X 1285:f, margin with prickles, X 416. 78 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE43.-Abaxial epidermis Bromunzolu gosswezlerz, Jackson 47: a, overview, X 4 16; b, stomata and interstomatal cell, X 128.5; c, costal silica bodies (sb) and cork cells (cc), X 867; d, microhair, X 1696; e, base of macrohair, X 625;S, overview showing transverse veins, X 121. NUMBER 49 79

PLATE44.-Adaxial epidermis Bromuniola gossweileri, Jackson 47: a, stomata and interstornatal cell, X 416: b, long cells, X 1285; c, intercostal prickles and hooks, X 295; a', costal silica bodies (sb) and cork cells (cc), X 625; e, microhair, X 1696;h base of macrohair, X 29.5. 80 SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE45.-Abaxial epidermis Me,gaslachya mucronala, Faden 74/345: a, overview, X 295; b, stoma, X 1696; c, interstomatal cells, X 867; d, costal silica bodies (sb) and cork cells (cc), X 867; e, microhair with thin apical cell (arrow), X l696;J overview showing transverse veins, x 121. NUMBER 49 81

PLATE46.-Adaxial epidermis Megastachya mucronala, Faden 74/345: a, overview, X 295: b, stomata. interstomatal cell and long cells, X 416: c, papillate warty surface, X 1285, d, bicellular prickle, X 1285: e, costal cork cells (cc) and silica bodies (sb), X 867:J pcirtion of microhair, X 1285. 82 SMITHSONIAN COKTRIBUTIONS TO BOTANY

PLATE4i.-Abaxial epidermis Orlhoclada africana. Paterson s.n.: a, stoma, X 2970; b, interstornatal cell, X 867; c, costal silica bodies (sb) and cork cells (cc), X 867; d, intercostal silica bodies and microhair. X 867: e. macrohair with curved tip and long cells, X 625: J; overview showing transverse veins. X 63. NUMBER 49 83

PLATE48.-Adaxial epidermis Orlhoclada africana, Paterson .s.n.: a, stoma, X 867: b, long cells, X 416: c, costal silica bodies (sb) and cork cells (cc), X 867; d, microhair, X 867; e, macrohair with curved tip, X 625;J; overview showing transverse veins, X 63. Index to Grass Species

(Major treatment in italics)

Andropterum stolzii, 14 (fig.) Leersza hexandra, 20. 50 (pi ), 51 (pl.) ilrundinaria alpina. 6 (fig.), 1.5%3b (pl.), 37 (pl). Leptaspis cochleata. 18. 46 (PI.), 47 (pi.) Asthenatherum forsknlii, 13 (fig.) Lepturus repens, 9 (fig.) glaucum. 24. 64 (pl.). 65 (pi.) Aoena abyssinica. 7 (fig.). 1 I (fig.) Maltebrunia leersiotdes, 6 (fig.), 20, 52 (PI.). 53 (pi.) Megastachya mucronata. 13 (fig.), 30. 80 (pi ). 81 (pi.) Brachiaria brirantha, 13 (fig.) Bromuniola gossreieileri. 29, 78 (PI.), 79 (pl.) Ntyraudia arundinacea. 27, 72 (PI,), 73 (pl.)

Chloroca!ymma cytocantha, 6 (fig.) Obra luttfolia, 8 (fig.), 10 (fig.), 18, 41 (PI.), 45 (pi.) Chysochloa hindsii. 10 (fig.) Oreobambos buchrcaldii7 16, 38 (PI.). 39 (pl.) Cleislachne sorghozdes, 14 (fig.) Oropetium thomaeum. 14 (fig.) Cuelachne africana, 7 (fig.) Orthoclada africana, 8 (fig.), 9 (fig.). 12 (fig.). 14 (fig.). 15. 30, Colpodium rhionogeiton. 11 (fig.) 82 (pl.),83 (pl.) Commelinidium mayumbense, 7 (fig.) Orpa barthii, 9 (fig.): 10 (fig.) Crinipes abyssinicus. 7 (fig.). 25. 66 (pl.). 67 (pl.) punctata. 21, 54 (PI,), 55 (pi.) Cpnodon dacblon, 12 (fig.) Oxylenanthera abyssinica, 16, 40 (p1.j. 41 (pl.)

DacyliJ ,glomerata, 7 (fig.) Pentaschistis borussica, 28. 74 (pi.). 75 (pl.) Dacyloctenium giganteum, 12 (fig.) minor. 28 Daknopholis boiuinii, 9 (fig.) Phacelurus huillensis, 8 (fig.), 10 (fig.) Danthoniopsis uridis. 14 (fig.), 15 Phragmites maurit~anus,24. 62 (pl.). 63 (pl.) Dichanthium aristatum. 13 (fig.) Phyllorhachis sagittutu, 22, 58 (pi.)?59 (pl.) Pueiia o&rformis. 17, 42 (PI.), 43 (PI.) Ech~nochloacolona, 9 (fig.) pyramidalis. 6 (fig.) Sacciolepis africana. 7 (fig.) Ehrharta erecla, 23, 60 (pl.).61 (pl.) Schmidtia bulbosa, 11 (fig.) Eleuszne coracana, 6 (fig.) Sehima neruosum? 13 (fig.) Elqtrophorus globularis, 11 (fig.), 12 (fig.), 26, 68 (pl.)>69 (pl.) Sorghum arundinaceum, 8 (fig.) spi ca t us, 2 6 Stipa drageana, 10 (fig.) Streptogyna crinita, 19, 48 (pi.). 49 (pl.) Habrochloa bullockii, 26, 70 (PI.), 71 (pl.) Harpachne srhimperi. 12 (fig.) Trichoneura mollis, 11 (fig.) Helictotrichon elongalurn, 6 (fig.) Tnraphisfleckit, 8 (fig.) Heteroanthoecia guineenszs, 10 (fig.) schinrii, 28, 76 (PI.), 77 (pl.) Humbertochloa grfenwayi, 12 (fig.). 22. 56 (pl,). 57 (pi.) Triticum aesticum, 11 (fig.)

Isachne buettneri, 14 (fig.) Vossia cuspidata, 9 (fig.)

84