PUBLICATIONS OF THE MUSEUM TEXAS TECH UNIVERSITY Three publications of The Museum of Texas Tech Uni¬ versity are issued under the auspices of the Dean of the Graduate School and Director of Academic Puhlications, and m cooperation with the International Center for Arid and Semi-Arid Land Studies. Short research studies are published as Occasional Papers whereas longer contributions apj^ear as Special Publications. Papers of practical application to col¬ lection management and museum operations are issued in the Museology .series. All are numlx'red separately and pub¬ lished on an irregular basis. The preferred abbreviation for citing Ehe Museum’s Occa¬ sional Papers is Occas. Papers Mus., Texas Tech Ihiiv. Institutional subscriptions are available through Texas Fech Press, Texas Tech Ihiiversity, Lubbock, Texas 79409. Institutional libraries interested in exchanging publications should address the Exchange Librarian at Texas Tech Uni¬ versity. Indi\iduals can purchase separate numbers of the Occasional Pairers for $1.00 each from Texas lech Press. Remittance in U.S. currency check, money order, or bank draft must be enclosed with request (add $1.00 per title or 200 pages of publications requested for foreign postage; resi¬ dents of the state of Texas must pay a 5 per cent sales tax on the total purchase price). Copies of the “Revised checklist of North American mammals north of Mexico, 1979’’ (Jones et al., 1979, Occas. Papers Mus., Texas Tech Univ., 62:1-17) are available at 60 cents each in orders of 10 or more. T t ^ 7 r7 GW OCCASIONAL PAPERS., THE MUSEUM S. COMO ZC'JI L ^ 9 4.. TEXAS TECH UNIVERSJ(TY v/ ry M MBER 64 20 JUNE 1980 KEY TO SELECTED PLANT SPECIES OF TEXAS USING PLANT FRAGMENTS Gretchen Scott and B. E. Dahl Accurate e\aluation of the seasonal diet of grazing animals greatly facilitates application of range and wildlife management principles. Deciding which season(s) of the year is most appro¬ priate to use the range, what the proper kind(s) of grazing animals should be, or when the animal’s diet is most likely to need a nu¬ trient supplement obviously requires knowledge of food habits. .Accurate identification of plant fragments in animal feces would reflect which plant species were being eaten. Ob\ious adxantages of assessing diet composition via these means are: wild and domesticated herbivores need not be sacrificed to examine stomach contents, diet information can be gathered from animals occupy¬ ing rough terrain where ocular observations or fistula techniques are not possible, animals can graze or browse naturally without observer distraction, and one to several days diets is integrated into one sample (that is, observations are not limited to one or two hours per day). Although unequal digestion of consumed plant spec ies can bias quantitative diet values, the rnicrohistological evaluation of feces has proven to be of real value in diet analyses. .A good approxi¬ mation of the diets of grazing animals now is considered feasible (Deardene/fl/., 1974). The diagnostic key presented herein was prepared as an aid for those interested in applying the rnicrohistological technique in Texas or in areas where similar vegetation is found. Measure¬ ments in text are given in millimeters, volumes in mililiters, and 2 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY weights in grams. For convenience, photomicrographs of reference and fecal material are grouped into plates. Diagnostic Characteristics Grasses Grasses have a linear cell arrangement that can be divided into costal and intercostal zones (Metcalf, 1960). The costal zone, occurring over the veins, is the most useful for species identifica¬ tion because the veins and adjacent cells are not digested as easily as cells of the intercostal zone (areas between veins). Diagnosti¬ cally useful structures of the costal zone are silica cells, cork cells (collectively called short cells), and bristles. In the intercostal zone lie long cells, stomata and their accompanying guard and subsid¬ iary cells, and protrusions such as microhairs, bristles, and tri- chomes. Cork cells, bristles, and silica cells also are present in the intercostal zone of some species. Silica cells are especially important in diet analysis for they assume a variety of distinctive shapes as shown in Fig. 1. These cells, filled with silicon dioxide, are not digested by the animal and are sometimes the only remnant of the grass visible in the feces. If a grass has silica cells in the intercostal zone, they may not be the same shape as those in the costal zone. The frequency and pattern of occurrence of silica cells are important for identify¬ ing grasses. Cork cells are visible in the costal and intercostal zones of most grasses. They occur individually, usually at the end of a long cell, or in pairs with silica cells. Cork cells also assume a variety of shapes as shown in Fig. 2A-D. Bristles can be present in the costal or intercostal zones and at leaf margins. They appear as flat, hairlike protrusions that are rounded at one end and pointed at the other as in Fig. 2E. Microhairs are two-celled microscopic epidermal protrusions with or without a stem (Fig. 2F-H). They can be found in both the costal and intercostal zone. The distal segment can vary in shape from short and round to long and narrow. Often the seg¬ ment is missing. Trichomes, or macrohairs, arc large unicellular hairs visible with the naked eye or a hand lens (Fig. 3A). Trichomes of grasses often are not seen in fecal slides as they occur only at the leaf margins. Long cells of the intercostal zone of grasses vary in shape and size as shown in Fig. 3B-E. The ends of these long cells are often SCOTT AND DAHL— PLANT SPECIES OE TEXAS 3 Fig. 1. — \'arious form.s of silica cells; A, rouiui; B, square; C., barbell; D. wreiic b; E, nodular; F, H-shaped; G, X-shaped; H, saddle-sba|)ed. Pig. 2. — \'arious forms of cork cells; A, round; B, srpiare; C, oblong; D. paired with a silica cell to appear crescent-shaped; P., bristle — a flat, bairlike protrusion. \'arious forms of microhairs; F, with stem and rounded distal cell; C., without stem and with long distal cell; H, with distal cell missing. Fig. 3. — \’arious forms of macrohairs in grasses; \. long and thin (left) and short and thick (right). \’arious forms of long cells of the intercostal /one; B, rec¬ tangular; C, square; D, hexagonal; E, oval. \’arious forms of long tell walls; P, pointed (top), rounded (middle), or square (bottom); G, deep (top) and shallow (bottom); H, even (top) and uneven (bottom) undulations. 4 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY 4 5 Fig. 4. — Various forms of subsidiary cells of grass stomata: A, round; B, square; C, triangtdar; D, oval; E, flat. Leaf sheath epidermis, F. Costal and intercostal arrangement of grass leaf, G. Grass seed, H. Fig. 5. — Various forms of unicellular trichomes of forbs; A, smooth (top) and pubescent (bottom); B, branched (top) and unbranched (bottom); C, attached at an end (top) and attached in the center (bottom); D, straight (top) and curved (bot¬ tom). Various forms of multicellular trichomes of forbs: E, dendroid; F", peltate; G, stellate; H, single row of cells. useful in identifying plant fragments in the feces. The cells may be joined by silica cells, cork cells, or a pair containing both. Microhairs also can serve as part of the cell end. Shape of the cell wall is distinctive and hence a good diagnostic character in grasses (Fig. 3F-H). Stomata in Graminea and Cyperacea are similar, but there are noted differences in the shape of the subsidiary cells. Subsidiary cells of grass stomata can assume any of the various shapes out¬ lined in Fig. 4A-E; these are diagnostic but they can be distorted during digestion or preparation of the microscope slide. There¬ fore, species identification solely on the appearance of the subsid¬ iary cell could be misleading. All grass stomata have two such cells parallel to the stoma’s long axis. Guard cells appear barbell- SCOTT AND DAHL— PLANT SPECIES OE TEXAS 5 6 Fig. 6. — Various forms of stellate trichomes of forbs; A, many long thin arms with special center attachment; B, arms of medium length and width, center point of attachment: Ci, few short thick arms with no spetial form of attachment; D, arms evenly (left) or unevenly (right) spaced; E, arms uniform length (left) and variable in length (right); h', arms bent (left) and straight (right); Ci, arms tapering from wide at base to thin at distal end (left) and arms uniform in width (right). Components of forb stomata are two half-moon shaped guard cells surrounding the pore or opening itself, H. Fig. 7. — \'arious arrangements of subsidiary cells around the stomata of forbs: .\, anomocytic with lU) special cell arrangement; B, anisocytit with three sidtsidiary cells present one smaller than the other two; paracytic with one or more subsid¬ iary cells octtirring on either side oi the stomata parallel with its long axis; D, diacytic with two subsidiary cells enclosing the stomata, their (ommon wall at right angles to the long axis of the stomata; E, actinotvtii with subsidiarv (ells arranged in a circular pattern. .Shapes of (cll walls ol forbs are dentate (left) oi smooth (right), F. Components of brush stomata are two kidney-shaped guard tells surrounding the pore or opening itself, CF Basit shape ol tiit homes ol woody spe¬ cies, unicellular and short, H. shaped, due to the center pore or opening itself. Stomata fre¬ quency may differ according to site and environmental condition within any one species. I'hus, this feature is not often useful in identifying species. 6 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Different parts of grass plants have different epidermal charac¬ ters, for example, the leaf sheath (Fig. 4F) is composed only of long cells, and the leaf itself consists of costal and intercostal zones (Fig. 4G) and all their components. Consequently, leaves are the best tissue for identification of grasses. Grass seeds are poor diagnostic tissues for they all are fairly similar and usually too dense for light from the microscope to penetrate, as shown in Fig. 4H. Forbs Forbs do not have a linear cell arrangement, nor can they be divided into costal or intercostal zones. Furthermore, cork and sil¬ ica cells are absent. Trichomes are the outstanding character by which forbs may be identified under the microscope because they exhibit distinctive shapes and are not easily digested. They may be either unicellular or multicellular (Fig. 5A-H). Stellate trichomes vary in the length, width, and number of arms they support and also in the manner in which the arms are attached (Fig. 6A-G). Stomata consist of the pore, two half-moon shaped guard cells (Fig. 6H), and occasionally subsidiary cells. Subsidiary cells form special arrangements around the stomata as shown in Fig. 7A-E. Cell walls can be dentate or smooth (Fig. 7F). The size, shape, and arrangement of the cells are useful in diet analysis if they are visible m the fecal slide. Shape and depth of the cell wall undula¬ tions are also helpful in identifying plant fragments. Woody Plants Shrub or woody species have cell arrangements and configura¬ tions similar to forbs. The cells usually have smooth walls, and stomata are small with kidney-shaped guard cells (Fig. 7G). (The guard cells of some woody species are similar to the half-moon shaped guard cells common in forb species). Trichomes are gener¬ ally unicellular (Fig. 7H), the one exception being the Quercus species, which have peltate trichomes. The cell structure of woody species is usually visible in the fecal slide. However, pigments are not always removed during diges¬ tion and this can mask characters needed for identification. Cell walls may be smooth or dentate. Epidermal cells of woody species are most often smaller than those of forbs. Nuts, berries, and seeds from woody plants are useful aids in determining the species of a plant fragment. SCOTT AND DAHL— PLANT SPECIES OE TEXAS 7 Methods and Materials Reference Slides There must be a complete plant collection from the area to be studied in order to prepare reference slides. Two separate slides of each plant part (leaf, stem, flower, seed, berry, and so forth) shoidd be prepared. The pigments in grass tissue must be removed with hot water and 95 per cent ethanol so that epidermal characters can be seen. Fresh material, which loses its pigments readily, is easier to work with than dried material; however, either is acceptable. It is advisable to cut fresh grass into small pieces and soak them for at least 24 hours in 95 per cent ethanol. Frag¬ ments are next blended until pigment is removed, and slides pre¬ pared according to instructions in the following section. Check slides under the microscope to be sure epidermal characteristics are visible. If still obscured by pigment, take the remaining plant material from the 200 mesh screen and reblend it with hot water and alcohol. Repeat until all epidermal characters arc clearly visible. Forbs require only the use of hot water for preparation of refer¬ ence slides. Slides should also be prepared of any flowers, seeds, or berries. It is difficult to remove pigments from many woody species. Soaking plant parts in 95 per cent ethanol for at least 24 hours will usually aid in removing the pigments. Following soaking, leaves are blended with hot water and alcohol. This method will not extract all color from nuts and seeds, but it will closely simu¬ late the action of an animal’s digestive system. Before discarding plant material collected for the preparation of reference slides, check reference slides to be sure epidermal characters needed for identification are visible. Slide Preparation Microscope slides are prepared using the method described by Cavender and Flansen, 1970, and Hansen et ai, 1971. Ibis tech¬ nique is described below. Materials needed are: binocular microscope, lOOX; glass micro¬ scope slides, standard size and laboratory grade; glass cover slips, 22X40 mm.; slide labels; dropping bottles, 30 ml. (2); teasing nee¬ dle; spatula with narrow flexible blade; paper towels; 200 mesh screen; drying oven and racks; Waring blender (1 quart). Two chemical solutions are also used in making slides. Hert- wig’s solution is a clearing agent that consists of 270 g. cloral 8 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY hydrate crystals (a restricted drug requiring a BNDD number to purchase), 10 ml. of IN HCl, and 60 ml. glycerin. The glycerin and HCl are combined and then the chloral hydrate crystals added. The mixture is next warmed over an alcohol lamp and stirred until all crystals dissolve. Hoyer’s solution is a mounting medium containing 200 g. chloral hydrate crystals, 50 ml. water, 20 ml. gly¬ cerin, and 30 g. photo purified gum arabic. After the glycerin and water are combined, the chloral hydrate crystals are added and the mixture warmed until the crystals dissolve. The gum arabic is added to the solution, which is then placed in a dark place until the gum completely dissolves. This could take as long as a week. Fecal samples should be blended at high speed for one minute, and two slides ought to be prepared from each sample. Plant fragments should be spread evenly over the slide and should not overlap. Best results are obtained when, at 100 power magnifica¬ tion, there are about three large fragments per field. Place approximately 10 ml. of ground or blended sample in a 0.1 mm. (200 mesh) screen and wash under running water for one minute. Remove a small amount of the washed material from the screen with a spatula and spread it near one end of a microscope slide. Add three or four drops of Hertwig’s solution to the wet material on the slide, then carefully evaporate most of it by hold¬ ing the slide above a small alcohol burner, while stirring with teasing needle. It is important not to completely evaporate the Hertwig’s solution, as it will make slides difficult to read. When most of the solution has evaporated, add enough Hoyer’s solution to cover an area about two-thirds as large as a cover slip. With a teasing needle, mix the plant material with the Hoyer’s and spread evenly over an area as large as a cover slip. Place a cover slip on the preparation and heat the slide over the burner until the Hoyer’s solution starts to boil. Immediately wipe the bottom surface of the slide with a cold, damp paper towel to draw air bubbles out of the solution. Using the handle of the teasing needle, gently press on top of the cover slip to squeeze out excess mounting medium and remove any remaining air bubbles. (Very tiny bubbles usually disappear during the drying process and are not detrimental.) Apply a thin ring of Hoyer’s solution around the edges of the cover slip, if needed, to form a seal as the slide dries. Slides are placed flat on racks at 55°C, for two or three days, or until the Hoyer’s solution has hardened, and are then stored in a dry place. Hoyer’s solution forms a permanent mounting medium SCOTT AND DAHL— PLANT SPECIES OF TEXAS 9 when hardened, bin is soluble in water allowing easy ( leaning lor reuse oi slides. Collection and Preparation of Fecal Material lo preserve tecal material until slides are to be made, store in 95 per cent ethanol, 10 {)er cent lormalin, or oven dry. Freezing tecal material can cause the cell walls of the plant fragments to burst. This makes identification extremely difficult, if not impossible. Feces from animals that eat many bard seeds or nuts should be air dried (or oven dried below 70°C) and then ground in a W'iley Laboratory Mill using the delivery tube with the 20 mesh (1 mm.) screen. Ground samples may be stored in coin envelopes or in jars until slides are to be prepared. To prepare slides from ground fecal material, place the sample in a 200 mesh (0.1 mm.) U.S. Standard Sieve and wash under running hot water for one min¬ ute, then prepare slides. Feces from animals that eat mainly grasses and forbs may be stored in 95 per cent ethanol. To prepare slides, put sample (and alcohol in which it was stored) into the blender, add hot water (at least enough to cover blender blades), and blend for one to three minutes depending on coarseness of plant material in sample. Pour blended sample into the 200 mesh screen and rinse with hot water, let drain, and prep^are slides. Key to Selected Plant Species Selected Major Groups I. (;ell arrangeniem linear . Ciell arrangement other than linear . 2. Distinct (ostal and intercostal zones; long cells ret tangular oi stjiiare; t ell walls sinufjus, hairs unicellular; stomata with suhsitliary cells paratytit; short tells present (silica and cork tells) . (.ramineae 3. No distinct zones trr true shtrrt tells . Plants with smotrth cell walls; stt)mata antrintu yt tit . . . some . Plants with cell walls sinuous ((Aperateae has bright cells, but do not appear tt) be true t)nes) . some . . 3 . Liliateae . spt)ts resembling silita . (Aperateae . Junt at eae 4. Tissue fragments without \isihle sttrmata, without t)icht)mes, thuse pies- . Tat tat eae I richomes uni or multicellular; druse absent; cells nt)t rectangular, nt) tlistinct zones or short cells; subsidiary cells, if present, vary in type . 5 10 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Cells colorless: tissue fragments usually absent in feces; trichomes common; normal stomata shape . Forbs Cells of tissue fragments appear thick, usually some pigment remains (yellow, brown, tan); trichomes usually unicellular (multicellular and peltate in Quer- cus species); stomata usually kidney-shaped . shrubs or trees Gramineae 1. Silica cells of the costal zone never H-shaped . 8 Silica cells of the costal zone H-shaped or similar . 2 2. Silica cells of the costal zone not distinctly H-shaped, varying from near H- shaped, to barbell-shaped, to X-shaped . 5 Silica cells of the costal zone distinctly H-shaped or nodular . 3 3. H-shaped silica cells over the veins greater than 0.0347 mm. in height; rounded cork cells at the ends of long cells in the intercostal zone . . Paspalum dilatatum H-shaped silica cells over the veins greater than 0 0347 mm. in height; without rounded cork cells at the ends of long cells in the intercostal zone . 4 4. Plants with H-shaped silica cells at the end of the long cells in the intercostal zone; the H-shaped silica cells are paired with crescent-shaped cork cells; sub¬ sidiary cells of the stomata triangular . Bothriochloa saccharoides Plants without H-shaped silica cells at the ends of long cells in the intercostal zone; cqrk cells in the intercostal zone round; subsidiary cells of the stomata oval . Schizachyrium scoparium 5. Long cells of the intercostal region not distinctly rectangular, more hexagonal or ov al . 7 Long cells of the intercostal region distinctly rectangular . 6 6. Silica cells of the costal zone not bone-shaped but saddle-shaped or nodular; silica cells of the intercostal zone rounded and paired with crescent-shaped cork cells . Panicum obtusum Silica cells of the costal zone bone-shaped to H-shaped; silica cells of the inter¬ costal zone similar and paired with square cork cells . Panicum obtusum Silica cells of the costal zone bone-shaped to H-shaped; silica cells of the inter¬ costal zone similar and paired with square cork cells . . Panicum coloratum 7. Silica cells of the costal zone predominantly H-shaped; large oval cork cells at cell ends in the intercostal zone; long cells more rectangular, but with rounded ends . Setaria leucopila Silica cells of the costal zone predominantly bone-shaped; sone H-shaped; occasional large oval cork cells . Setaria geniculata 8. Silica cells of the costal zone not round . 11 Silica cells of the costal zone rounded . 9 9. Silica cells of the costal zone irregularly rounded to oblong; infrequent long cell walls smooth; long trichomes or evidence of attachment of trichomes . . Bromus unioloides Rottnded silica cells of the costal zone smooth . 10 SCOTT AND DAHL— PLANT SPECIES OE TEXAS 11 10. Silica cells ol the costal /one rounded and paired with crescent-shaped cork cells; inicrohairs in the intercostal /one . Sporobolus cryptandrus Silica cells ol the costal /one rounded hut without cork cells; intercostal /one has round silica cells paired with crescent-shaped cork cells; long cell walls otily slightly detitate; subsidiary cells ol the stomata almost square . . Hordeum pusillum 1 1. Silica cells ol the costal /one not bone-shaped . 12 Silica cells ol the costal /one bone-shaped; hairs common, distinctive, shaped like rose thorns . Aristida purpurea 12. Silica cells of the costal /one not wrench-shaped . 13 Silica cells ol the costal /one wrench-shaped, usually in rows of three . . Hilaria belangeri 13. Silica cells of the costal zone square, not saddle-shaped . 16 Silica cells of the costal zone saddle-shaped . H H. Plants without distinct X-shaped silica cells in the intercostal zone . 15 Plants with distinct X-shaped silica cells in the intercostal zone, sometimes paired with accompanying cork cells; long cell ends rounded . . Cenchrus incertus 15. Plants with silica cells of the costal zone paired with crescent-shaped cork cells, long cells large (0.2316 mm. long by 0.0347 mm. high); short hairs at ends of the long cells . Elyonurus tripsacoides Plants with long cells of the intercostal zone rectangular; cell walls bulge dis¬ tinctly for stomata; numerous large, round, cork cells in intercostal zone; large hairs in t ostal zone or evidence of the attachment of such hairs . . Stipa leucotricha 16. Plants with stjuare silica cells in the costal zone, but without bristles . 18 Plants with square silica cells; bristles in the costal zone . 17 17. Ciell wall between silica cells relatively smooth; silica cells small (0.01158 mm. wide); bristles short (0.04632 mm. long) . Bouteloua curtipendula (iell wall between silica cells irregularly undulating . Chtoris verticillata 18. Plants with square silica cells in the costal zone only . 20 Plants with stpiare silica cells in both the costal and intercostal zones . 19 19. (iell walls of the costal zftne are relatively smooth or straight-sided, large oval stomata; silica cells paired with cork tells; some silica tells in the intertostal zone paired with cork cells . Trtdens congrstus Silica cells that octur iti the intertostal /true eath attomjranied by a cork tell; silica cells 0.0347 mm. high, cell walls t)f the costal ztttte ilentate anti . poitited . Bouteloua htrsula 20. C:ell walls of the costal zone slightly dentate . Buchloe dact\Undes Cell walls t)f the costal zone dentate and rountletl; Itrng cells of the intercostal zone much elongated . Eragrostis silveana Forbs 1. Platits with trichomes . Plants without visible trichomes 12 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY 2. Cell arrangement linear . 3 Cell arrangement not linear, stomata paracytic . Xanthocephalum texanum 3. Cell walls dentate . Cyperus species Cell walls smooth . 4 4. Linear rectangular cells having stomata without special subsidiary cells (anomocytic) . 5 Linear cells, semi-rectangular, with widest portion of cell at middle; stomata with paracytic subsidiary cells . Salsola kali 5. Plants with exceptionally long cells and with sunken stomata . . Allium drummondii Plants with rectangular cells, stomata not sunken . Nothoscordum bivalve 6. Trichdmes multicellular (having both multi and unicellular trichomes in Sida species) . 11 Trichomes unicellular . 7 7. Unicellular trichomes not branched . 8 Unicellular trichomes branched . Lesquerella lindheimeri 8. Trichomes without center attachment . 9 Trichomes with center attachment . Phyla incisa 9. Trichomes without minute spines . 10 Trichomes with minute spines . Oxalis dillenii 10. Trichomes curved . . . Trichomes not curved Oenothera speciosa ... Verbena plicata 11. Plants with stellate trichomes . 19 Plants without stellate trichomes . 12 12. Plants with trichomes consisting of a single row of cells . 13 Plants with dendroid trichomes . Chamaesarcha sordida 13. Top segment or cell of trichome elongated into a long tapering point . 15 Top segment of cell of trichome having a very short, acute point . 14 14. Trichomes with numerous minute spines having one long middle segment in addition to the basal attachment and the short top segment . . .Zexmenia hispida Trichomes without spines, having three middle segments in addition to the basal attachment and the short top segment . Simsia calva 15. Trichomes not having top segment hook-shaped . 16 Trichomes having top segment hook-shaped, stomata sunken . Commelina erecta 16. Trichomes more than two segments . 17 Trichomes with two segments bearing minute pubescences .... Kochia scoparia 17. Trichomes with predominantly three segments . 18 Trichomes with 2, 3, or 4 segments; trichomes unusually long, shortest 0.926 mm. average 1.3896 mm . Rudbeckia serotina SCOTT AND DAHL— PLANT SPECIES OF TEXAS 13 18. Distal sfgnu'iit of trichoiiu' k“ss than 0.2316 inm. long; basal segnunit much thicker than other segments . -irnbrosia pstlostachya Distal segment ol trichome more than 0.2799 mm. long; top segment much longer than other segments . Ratibida columnarts 19. Stellate trie homes with more than four arms . 20 I richomes with four arms in parallel pairs, resembling a large H . . Malva.strurn coromandeltanum 20. rrichomes with 10 arms or less . 23 Erichomes with inc^re than 10 arms . 21 21. Erichomes with arms wider at base and tapering to a point, not stringlike . 22 Erichomes very slim, appearing siringlike, not wider at base of arms . . Sphaeralcaea lindheimeri 22. Erichome arms less than 0.405 mm. in length . Solarium elaeagnijolium Erichome arms more than 0.405 mm. in length; two trichomes commonly connected by a section of tissue . Croton capitatus 23. Trichome arms over 0.174 mm. in length . 25 Erichome arms 0.174 mm. or less in length . 24 24. Erichcjme arms unequal with at least two arms conspicuously longer than the others; when visible, there is a basal attachment for the trichome . . Si da filicaulis Erichome arms relatively equal in length; basal attachment for trichome con¬ stricted just above attachment . Abutilon incanum 25. Erichome arms relatively symmetrically arranged and of equal length . . Malvastrum aurantiacum Erichome arms not symmetrical, with at least two arms conspicuouslv longei than the erthers . Sida ciUaris Shrubs 1. Plants without glandular trichomes . 2 Plants with glandular trichomes . Rhus aroniatica 2. Trichomes unicel hilar . 3 Erichomes multicellular, [rebate . Qurreus larginiana 3. Trichomes with basal attac hment . ^ Erichermes with center attachment . Rumrha lanuginosa 4. Trichomes relatively short and thick, under 0.19686 mm . 6 Erichomes Icrng and thin, over 0.19686 mm . 5. Trichomes over 0.19686 mm. but under 0.3474 mm . Ziziphus obtusijolia Trichomes over 0.3474 mm., thicker at base . Celtis reticulata 6. Cell walls w^avy and stomata anomocytic . Diospyros texana Cell walls smooth and stomata paracytic . Prosopis glandulosa 14 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Grasses Aristida purpurea. — Silica cells in the costal zone barbell¬ shaped; occasionally, oval to square-shaped cork cells at the ends of the long cells in the intercostal zone. Long cell walls dentate; cells rectangular. Cork cells best seen at 4()0X. A. purpurea has bristles paired with silica cells over the veins. Trichomes resemble rose bush thorns. Reference slide lA; fecal slide IB. Bothriochlea saccharoides . — Silica cells H-shaped, occurring in the costal and intercostal zones. Cork cells rotmd, coupled with silica cells or at ends of long cells. Long cell walls thick and sin¬ uous. Stomata have triangular-shaped subsidiary cells. Reference slide 2A; fecal slide 2B. Bouteloua curtipendula . — Even, smooth rows of square silica cells in the costal zone, as well as microhairs present in this region. kTequent bristles occur in the costal zone. In the intercos¬ tal zone, long cells rectangular in shape with ends either cork cells or cork cells paired with square silica cells or sometimes bris¬ tles. In fecal slides, the costal zone, with its smooth cell walls, will be apparent. Reference slide 3A; fecal slide 3B. Bouteloua hirsuta. — Silica cells of the costal region square; those of the intercostal zone each accompanied by a cork cell. Cell walls of the costal zone dentate and pointed. Bristles infrequent or absent. Reference slide 4A; fecal slide 4B. Bromus unioloides. — Silica cells of the costal zone circular to oblong with sinuous walls, whereas silica cells of the intercostal zone oval, paired with crescent-shaped cork cells. Cell walls of the long cells have shallow undulations. Trichomes long and thin when visible with large base— usually appears to have no silica cells and smooth long cell walls. Stomata without visible sub¬ sidiary cells. Reference slides 5A, 5B; fecal slides 5C, 5D. Buchloe dactyloides.—SiVu^. cells of the costal zone square. Rows of long cells containing stomata wider than other rows of long cells. Cell walls of the costal zone wavy or moderately sinu¬ ous. \Try long microhairs in the intercostal zone, when \isible. Cell ends are silica cells paired with cork cells. Reference slide 6A; fecal slide 6B. Cenchrus incertus. — Silica cells in the costal zone saddle- shaped, bristles also a{)parent in the zones. Silica cells in the intercostal zone X-shaped. Long cells rectangular and sinuous. Subsidiary cells of stomata indistinct. Cork cells of intercostal zone round, occurring at the ends of long cells. Reference slide 7A; fecal slide 7B. SCOTT AND DAHL— PLANT SPECIES OF TEXAS 15 Chloris verticillata. — Silica cells in costal /(jiie scjuare, with \eiy dentate cell walls between them. Bristles in costal zone. Sto¬ mata lrec|uent, evenly spaced, and round. Long cells reciangnlar with dentate cell walls. Ciork cells present at ends oi long cells. Reference slide 8.V; fecal slide 8B. Elyoiiurus tripacoides. — Silica cells in costal zone sacfdle- shapecl, sometimes paired with crescent-shaped cotk cells. Lc^ng cells ol intercostal zone rectangnlar to diamond-shaped, with cork cells at their ends. Ciell walls thick and sinuous. Stomata have oval to triangular subsidiary cells. Bristles at the ends of some long cells. Reference slide 9A; fecal slide 9B. Eragrostis silveana. — Silica cells of costal zone square, some¬ times paired with cork cells; silica cells of intercostal zone not paired with cork cells. Lhiiform cell structure. Stomata round. Reference slide lOA; fecal slide lOB. Hilaria belangeri. — Silica cells of costal zone wrench-shaped, usually in rows of three; bristles noted in costal zone. Intercostal zone occasionally appears covered with black dots. Reference slide llA; fecal slide IIB. Hordeum pusillum. — Silica cells in costal zone round; those in intercostal zone paired with crescent-shaped cork cells. Long cells of intercostal zone with shallow, sinuous cell walls. Stomata appear square. Reference slide 12A; fecal slide 12B. Panicum coloratum. — Silica cells in costal zone bone-shaped. Long cells of intercostal zone rectangular to diamond-shaped; cell walls not deeply sinuous. Bristles frequent in intercostal zone, sometimes paired with cork cells. Silica cells of intercostal zone bone to X-shaped, occasionally paired with a square cork cell. Subsidiary cells of stomata sometimes indistinct. Reference slide 13A; fecal slide 13B. Panicum obtusum. — Silica cells of costal zone saddle-shaped to nodular. .Silica cells of intercostal zone, when {iresent, rounded and paired with c rescent-shajied cork cells at ends ol long cells. Long cell walls of intercostal zone dentate, uneven, rounded; microhairs visible at ends of long cells. Stomata appc'ar triangu¬ lar. Reference slide 14A; fecal slide MB. Paspalum dilatatum. — .Silica cells of costal zone prc'clominantly H-shaped to nodular. Cell walls of intercostal zone unevenly dentate. H-shaped silica cells paired with cc^rk cells at ends of long cells. Stomata large. Reference slide L5A; fecal slide 1.5B. Schizachyrium scoparium.—Sihea cells in costal zone H-shaped to barbell-shaped. Cork cells oval, occurring at cell ends in inter- 16 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY costal zone. Bristles at some cell ends. Cell wall thick and sinu¬ ous. Cell ends are bristles, round cork cells, cork cells paired with silica cell, or a microhair. Long cells rectangular. No H-shaped silica cells in intercostal zone. Reference slide 16A; fecal slide 16B. Setaria geniculata. — Silica cells in costal zone bone-shaped, usually in rows of three. Long cells of intercostal zone rectangular to diamond-shaped, with cell ends rounded. Round cork cells present at ends of long cell; sometimes paired with oval silica cells. Reference slide 17A; fecal slide 17B. Setaria leucopila. — Silica cells of costal zone either saddle- shaped to H-shaped or nodular. Long cells of intercostal zone rec- tangidar, some hexagonal. Mict'ohairs present. Round cork cells present at some cell ends. Reference slide ISA; fecal slide 18B. Sporobolus cryptandrus . — Silica cells round, paired with crescent-shaped cork cells, in costal and intercostal zones. No apparent unpaired short cells. Long cells of intercostal zone bulge at stomata. Long cells rectangular and paired short cells at cell ends. Reference slide 19A; fecal slide 19B. Stipa leucotricha. — Silica cells of costal zone saddle-shaped, sometimes paired with square cork cells. Long cells of intercostal zone rectangidar and bulge at stomata; their ends have cork cells, sometimes paired with silica cells. Reference slides 20A, 20B; fecal slide 20C. Tridens congestus. — Silica cells of costal zone square and not paired with cork cells. Cell walls of costal zone smooth and straight sided. Long cells of intercostal zone rectangular, with cork cells at cell ends. Reference slide 21 A; fecal slide 21 B. Forbs Abutilon incanum. — Stellate trichomes, usually five to 12 short arms; basal attachment is constricted just above the point of at¬ tachment. Arms relatively uniform in length. Reference slide 22A; fecal slide 22B. Allium drummondii. — Cells arranged in parallel rows, walls smooth, ends indistinct. Cells wider in middle than at either end; cells exceptionally long and without visible trichomes. Stomata sunken, anomocytic. Reference slide 23A; no photo of fecal slide available as digestion is complete. Ambrosia psilostachya. — Cell walls smooth. Trichomes pre¬ dominately three segmented, basal segment being much thicker than others. Stomata anomocytic. Reference slide 24A; fecal slide 24B. SCOTT AND DAHL— PLANT SPECIES OE TEXAS 17 Cfiamaesarcha sordida. — Cell walls dentate and angnlai. Iii- choines dendroid, nsually branched into two arms. Stomata ano- mocytic. Reference slide 25A: fecal slide 25B. Commelina erecta. — Oil walls smooth, angular, rrichomes three-segmented; distal segment bent and resembling a hook. Stomata large, sunken, and paracytic. Reference slide 26A, sunken stomata; 26B, trichomes; fecal slide 26Ci, trichome. Croton capitatus. — Stellate trichomes, 10 to 15 arms. Arms uni¬ form in length and evenly spaced, llsually two trichomes are con¬ nected. Reference slides 27A, 27B; fecal slide 27C. Cyperus stringosus. — Costal and intercostal zones both appear present. Silica cells visible as bright bumps. Long cells cuboidal. Stomata diacytic. Reference slide 28A; fecal slide 28B. Juncus brachycarpus. — Cell walls smooth. Stomata anomocytic. Reference slide 29A (leaf), 29B (seed). No fecal slide photo availa¬ ble as digestion is complete. Kochia scoparia. — Trichomes with two long, thin, pubescent segments. Reference slide 30A; fecal slide SOB. Lesquerella gordonii. — Trichomes branched, usually with four main arms, each of which branches into two arms. Trichomes also show a circular protrusion at the center. Cells puzzle-shaped. Stomata small and anisocytic. Reference slide 31 A; fecal slide 3 IB. Malvastrum aurantiacum. — Trichomes stellate with approxi¬ mately eight, thick, yellow-colored, arms. Arms uniform in length and evenly spaced. Reference slide 32A; fecal slide 32B. Malvastrum coromandelianum. — Trichomes large and Id- shaped. Arms thick and yellow. Pollen round and spikey. Refer¬ ence slide 33A (pollen), 33B (trichome); fecal slide 33C7 Nothoscordum bivalve. — Cells in a linear arrangement in paral¬ lel rows. Cells also rectangular with smooth walls. Stomata ano¬ mocytic, not sunken. Reference slide 34A; no fecal slide available as digestion is complete. Oenothera speciosa. — Cell walls wavy. Iric homes unicelhdar and sometimes pubescent. Stomata anomocytic. Pollen dark gc;)lcl, having three winglike parts marked with parallel lines. Reference slide 35A (pollen), 35B (trichome), 35C (flower); fecal slide 351). Oxalis dillenii. — Trichomes unicelhdar, pid)escent, and occa¬ sionally appearing pink or purple in color. I richomes also slightly curved; a small stem attaches it to epidermal tissue. Refer¬ ence slide 36A; fecal slide 36B. Phyla incisa.— Trichomes unicellular, tapered at both ends, and attached at center. Reference slide 37A; fecal slide 37B. 18 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Ratibida columnaris. — Trichomes three-segmented; distal seg¬ ment at least twice as long as others. Reference slide 38A; fecal slide 38B. Rudbeckia serotina. — Trichomes extremely large, usually con¬ taining four segments. Reference slide 39A; fecal slide 39B. Salsoa kali. — Cells in a linear arrangement in parallel rows. Cell walls smooth, narrower at ends than in middle. Stomata paracytic. Reference slide 40A (leaf), 40B (trichome). No fecal slide photo available as digestion is complete. Sida ciliaris. — Trichomes stellate with at least two arms longer than others; some trichomes extremely long and unicellular. Arms thick and unevenly spaced. Reference slide 41A; fecal slide 41B. Sida filicaulis. — Trichomes essentially stellate with basal at¬ tachment; stellate arms, short and thin, numbering approximately seven; at least two arms longer than others. Some short unicel¬ lar trichomes. Reference slide 42A; fecal slide 42B. Simsia calva. — Trichomes smooth and four-segmented; distal segment very short and pointed, caplike. Reference slide 43A; fecal slide 43B. Solanum elaeagnifolium. — Trichomes stellate. Arms usually eight to 14 in number, uniform in length and spacing, but wider at base than tip. Reference slide 44A; fecal slide 44B. Sphaeralcea lindheimeri. — Trichomes stellate. Arms generally 14 to 16 in number, long, and very thin, curved, and evenly- spaced. Reference slide 45A; fecal slide 45B. Verbena plicata. — Trichomes unicellular, not curved, and with basal segment much larger than distal segment. Cell walls angu¬ lar. Stomata anomocytic. Reference slide 46A; fecal slide 46B. Xanthocephalum texanum. — Cell walls smooth; cells square or rectangular. No visible trichomes. Stomata paracytic. Reference slide 47A; fecal slide 47B. Zexmenia hispida. — Trichomes with a basal cell, a long middle segment, and a caplike distal segment. Trichomes covered with minute spines, except for the caplike distal segment. Reference slide 48A; fecal slide 48B. Shrubs Bumelia lanuginosa. — Trichomes unicellular and attached to the epidermis by a branched arm at the center. Reference slide 49A; fecal slide 49B. Celtis reticulata. — Trichomes unicellular, long, and thin; basal portion much thicker than distal portion. Reference slide 50A; fecal slide 50B. SCOTT AND DAHL— PLANT SPECIES OE TEXAS 19 Diospyros texana. — riichonies short, thick, anci unicellular. Ck‘11 walls wa\y. rriangular attachment. .Stomata anomocytic. Reterenee slide 51 A; teeal slide 51 B. Opuntia polycantha. — Ckdls, octangular in shape, oftentimes dense and yellc^w in color. Other parts of epideiniis with indis¬ tinct cell walls and large round druse or circular indentations where druse had been. Stomata paracytic. Pollen is large and round, golden brown in color. Lighter gold areas sunouncled by darker colored cells; appear lacy. Seed coat a series cjf stacked cir¬ cular cells. Reference slides 52A (octangular cells), 52B (druse), 520 (pollen), 52D (seedcoat); fecal slide 52E (druse). Prosopis glandulosa. — Trichomes unicellular, short, pubescent. Leaf cells smooth walled, scptare or rectangular in shape. Stomata paracytic. Sprouts with very small, unicellular, pubescent tri- chc:)iTies. Lhorns show small, paracytic stc:)mata and very short, smcjoth trichomes. Bean pod has indistinct cell walls but enlarged stomata. Reference slides 53A (leaf), 53B (bean), 530 (sprout), 53D (thorn): fecal slides 53E (leaf), 53k' (bean), 53G (thorn). Quercus virginiana. — Trichomes peltate; center attachment unicjue, much different from forbs. Arms uniform in length and all curved in same direction; arms lacking special means of at¬ tachment, just come together. Reference slide 54A: fecal 54B. Rhus aromatica. — Trichomes nmltic elhdar, glandular, with a single base cell; several cells attached to base cell give trichome a mushroomlike a{)pearance. Trich(3mes also large, unicellular. Oell walls smooth. .Stc:)mata frecjuent, anomocytic. Ehe berry of this [jlant is important in diet work. .Stomata large, cells cuboidal and cream colored. Centers of cells are either I^aler or darker than rest of cell. Reference slides 55A (glandular trichcjme), 55B (berry), 55Ci (trichome), 55D (bark): fecal slides 55E (trichome), 55 E (berry). Ziziphus obtusifolia. — Ei ic home’s itdrecjueni, unic ellular. C.ell wall smooth; cells scjuare to rectangidai. Stomata paracytic. Ref¬ erence slides 56A (trie home), 56B (bark); fecal slide 56G. Insect Part \o cell walls, pigmented, usually ai)pears transparent, kecal slide 57 A. CTossarv Costal zone. — longitudinal zone of grass leaf that follows the veins. Dentate. — indentations in cell wall. 20 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Druse. — a group of crystals formed by deposits of inorganic materials, usually calcium oxalate. Group of crystals united into a compound structure. Intercostal zone. — longitudinal zone of the grass leaf between the veins. Long cell. — found in the intercostal zone of grasses; usually of a somewhat rec¬ tangular shape, being longer than wide. Microhair. — two-celled hair, although the distal cell is commonly missing, that appears in the costal and intercostal zones. Short cells. — occur in the costal and intercostal zones of grasses, but predomi¬ nantly in the costal zone. There are two kinds: cork cells, which are usually paired with silica cells or occur at the end of a long cell; silica cells, which appear in the costal and intercostal zones — those occurring in the costal zone are most useful as diagnostic characteristics of grasses. Sinuous. — with a strongly wavy margin. Stellate trichome. — refers to star-shape; many arms extend from a central point of attachment. Stomata. — in grasses, they occur only in the intercostal zone. In shrubs and forbs, the stomata are dispersed throughout the leaf. Stomata consist of three parts; pore, the opening itself; guard cells, two cells that surround the pore and control the size of the pore opening; subsidiary cells, which always number two in grasses and occur next to the guard cells. In shrubs and forbs there are two or more sub¬ sidiary cells, or none at all, also next to guard cells. Trichome. — epidermal hair, sometimes called macrohair in grasses. Bristle. — also known as prickle hair. Robust, sharply but shortly pointed struc¬ ture with swollen base. In grasses only. Observed in the costal and intercostal zones. Peltate hairs. — shield-shaped hair attached by its lower surface. Undulations. — indentations in the cell wall. References Cavender, B. R., and R. M. Hansen. 1970. The miscroscopic method used for herbivore diet estimates and botanical analysis of litter and mulch of the Pawnee site. Tech, report. Ft. Collins, Colorado State Univ., 18:1-10. Croker, B. H. 1959. A method of estimating the botanical composition of the diet of sheep. New Zealand J. Agric. Res., 2:72-85. Dearden, B. L., R. M. Hansen, and R. K. Steinhorst. 1974. Analysis of the discernability of plant species during digestion. Tech, report, Nat. Res. Ecol. Lab., Colorado State Univ., 261:1-80. Esau, K. 1965. Plant anatomy. 2nd ed. New York, Wiley, xx+ 1-767. Hansen, R. M., A. S. Moir, and S. R. Woodmansee. 1971. Drawings of tissue of plants found in herbivore diets and in the litter of grasslands. Tech, report, P't. Collins, Colorado State Univ., 70:1-15+84 pis. Metcalf, C. R. 1960. Anatomy of the monocotyledons. I. Gramineae. Oxford, Clarendon, l;ixi+ 1-732. Metcai.f, C. R., and L. Chalk. 1950. Oxford, Clarendon. 1 :ixiv+ 1 -724; 2;725-1500. Schrumpf, B. J. 1968. Methodology for cuticular identification of selected east¬ ern Oregon range plants. Unpubl. M.S. thesis, Oregon State Univ. SCOTT AND DAHL— PLAN I SPECIES OF TEXAS 21 Plate 1.— Photomicrographs of reference and fecal slides for Anstida purpurea, lA-B; Bothriochlea saccharoides, 2A-B; Bouteloua curttpendula, 3A-B; Bouteloua hirsuta, 4A-B. 22 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY J 4 I 7A 7B Plate 2. — Photomicrographs of reference and fecal slides for Bromus unioloides, 5A-D; Buchloe daclyloides, 6A-B; Cenchrus mcertus, 7A-B. SCOTT AND DAHL— PLANT SPECIES OF TEXAS 23 Plate 3. — Photomicrographs of reference and tecal slides for Chloris verttcjllata, 8A-B; Elyonurus tnpsacotdes, 9A-B; Eragrostis silveana, lOA-B; Hilaria belangen, llA-B. 24 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY 12A -A' A ^ ■’ tv i .,;‘ 1 \\\' !•* ■‘■V. v - r< ■•/ ' ' — ) TEXAS TECH UNIVERSITy'"^""^ NUMBER 65 25 JULY 1980 SCORPIONS FROM THE VIRGIN ISLANDS (ARACHNIDA, SCORPIONES) Oscar F". Francke and VV'. David Sissom Three scorjDion species have been reported from the U.S. Virgin Islands, but no published records exist from the British Virgin Islands. Scorpio griseus Fabricius, 1793, originally was described from “America Insulis,’’ and subsequently was reported from St. Tho¬ mas as Tityus griseus by Kock (1845). Pocock (1893:391), however, considered both nominal taxa to be “of doubtful position both generically and specifically,” and indicated that “there is no apparent reason for su})posing that it [Tityus griseus Koch] is Scorpio griseus of Fabricius.” Kraepelin (1895, 1899), on the other hand, regarded them as conspecifics and treated griseus as a jun¬ ior synonym of Centruroides teslaceus (DeCieer, 1778) from Monteserrat. Fhe original description of .S', griseus Fabricius is so brief that even the familial position of this taxon cannot be determined with certainty. It was characterized in part as “Cor|)us parum, pallide testaceum, immaculatum...”, whereas T. griseus Koch was described and illustrated as having a definite fuscous pattern. 7'hus, as indicated by Pocock (1893), there is no apparent reason for recognizing .S. griseus Fabricius and T. griseus Koch as con- specifics. Furthermore, S. griseus is hereby considered a uoruen dubium because the type specimen(s) could not be located and must be regarded as lost (Dr. Henrik Enghoff, personal communi¬ cation), and the description and locality data available are insuffi¬ cient to identify this taxon with any degree of assurance. Study of