es eee beeeses 1% H ’ * t : i) 7 Tiretet rarer el Telefe seal ebubeh ni voie tite tokvbginbtedtve\ olin tedeseiedy nginsrftatelbitnstideytins OANA NEHER A RINRNCA beset S : pi =a : ar eWeCibspn- Inve Sei 1 Gaines Y OF ae aes i iE BOT Ea ai vane ye > ie : eee rye al . Che Kural Text-BWook Series EpItTEpD By L. H. Baitey MANN, BEGINNINGS IN AGRICULTURE WARREN, ELEMENTS OF AGRICULTURE WARREN, FarmM MANAGEMENT Lyon & Fippin, Sorin MANAGEMENT J. F. Ducerr, SourHERN FieLtp Crops B. M. Duaear, Puant PuystoLocy Harper, ANIMAL HUSBANDRY FOR SCHOOLS MontTcGomMErRy, Corn Crops WHEELER, MANURES AND FERTILIZERS Livineston, FreLp Crop PRopucTION WiptTsor, IRRIGATION PRACTICE Hircucocx, A Trext-Booxk or GRASSES Gay, Jupcine Live-Strocxk ae 7 Po fee Gwe ~ ye 7 "ae <——~ SS, ry AY) y “ % a ro —_—— — y = S SSO GET EZ fe a < a awe s aw Sf = . = CA Wg is \y : SS Aa = \ a i z ~ = Ses = = SS) Se . > _ = =~ SS zr iy : . 4 \ a = ————— . se ‘aaa ~~ é ® ~~ S —Ray=)\ = ~ 2 > . fe 5 — oa : SS S ‘ = Ses —= aS SSN ee N S YZ, S SASS = 3 \ x = =! \ ~ — % \ NS . SS SS : v AS = \ : “Wwe A TEXT-BOOK OF GRASSES WITH ESPECIAL REFERENCE TO THE ECONOMIC SPECIES OF THE UNITED STATES Me pelea 4 > > 3, , a - sie ‘ AV BMLICHOOCK "°c . e : 2 C.@ 1% SYSTEMATIC AGROSTOLOGIST, UNITED STATES DEPARTMENT OF AGRICULTURE, o° WASHINGTON, D. C.; FORMERLY PROFESSOR 9P cep IN’, mE? oie KANSAS STATE Agaisbuzy 341 col LEOE ae > ° ET , > 7 »s2 } 5 2 ov > a) dpew York THE MACMILLAN COMPANY 1914 All rights reserved Qe e a8 HSS Ooh: 1914 OMILLAN COMPANY a CopyRIGHT ° HE M e hd a PuWlished September, 1914. IPount Pleasant Press J. Horace McFarland Company Set up and electrotyped.* Harrisburg, Pa. PREFACE THE present work is primarily a text-book, but some technical information is included that might more properly be consigned to a reference book. To a considerable extent this reference matter is appended to text para- graphs in the form of notes in smaller type. Although the chief emphasis is placed on Systematic Agrostology, comprising Part II, a brief outline of Economic Agros- tology is presented in Part I. In this part the clovers and other forage plants not belonging to the grass family are referred to in classifying the forage plants and their uses. The reader will observe that by the plan adopted the information on a given grass is not found segregated in a single paragraph or chapter but is scattered to meet the necessities of the classification used. The index makes these scattered paragraphs readily accessible. The botanical information concerning each species will be found in the appropriate paragraph in Part II, but the economic information will be found classified in Part I, a part under the chapter on meadow plants, for example, and a part under the chapter on pasture plants. It seems to the author that this method has didactic advantages. In a reference book it might be more con- venient to have all the information on one species placed in sequence. Part'I is too elementary to meet the demands of a course in agronomy, but it is hoped that it may be found useful as a bridge to connect the subjects of Sys- tematic Agrostology and Agronomic Agrostology. (v) vi PREFACE The key to genera includes all the genera found grow- ing wild or in common cultivation in the United States. More complete descriptions of the more important genera are added under each tribe. For use as a reference work it would have been desirable to give full descriptions of each genus. But again the author’s course was modified by didactic requirements. It is unnecessary for the student to acquire information on the unimportant genera. The nomenclature followed is that of the American Code. Synonyms are introduced whenever a species or genus has been commonly known under another name. After careful consideration, the English system is used for all measurements except the small fractions of an inch. But for the smaller measurements the milli- meter is adopted as the unit. The English system is as yet more familiar than the metric for the larger measure- ments. The small fractions of an inch however are incon- venient. The line might be used but is unfamiliar and is too large a unit. The millimeter meets the requirements as to convenience and size of unit, and is sufficiently familiar to botanical students. | The habit drawings have been made by Mrs. Mary Wright Gill, the detailed drawings of the spikelet by Mrs. Agnes Chase. A..S. HITCHCOCK. WASHINGTON, D. C. May 12, 1914. TABLE OF CONTENTS PART I ECONOMIC AGROSTOLOGY CHAPTER I INTRODUCTION . eg ee =, ee Agrostology, 2—Economic agrostology, 2—Systematic agrostology, 3—The uses of grasses, 3—The value of farm crops, 4. CHAPTER II Economic CLASSIFICATION OF GRASSES Grains, 6—Uses of the grains for food, 6—Relative im- portance of the different grains, 7—Value and production of the cereals, 8—Starch, 11—Alcohol, 12—Miscellaneous uses, 12. CHAPTER III ForAGE PLANTS The importance of forage plants, 14—Natural classi- fication, 19—Legumes, 19—Miscellaneous, 21—Classi- fication of forage plants according to use, 22—Pasture plants, 22—Native pastures, 22—Ranges, 22—Over- grazing, 24—Rejuvenating wornout ranges, 25—Range grasses, 26. (vii) Paces 1-5 6-13 . 14-28 vill TABLE OF CONTENTS CHAPTER IV PaGes CurstvaTeEp PABTURES =. 3. Gee ok ee Permanent pastures .. . wo) aaa Pasture grasses, 5 Blue eraee, 20-Histalbiliahine a blue-grass pasture, 27—Bermuda-grass, 31—Estab- lishing a Bermuda pasture, 32—Other pasture- grasses, 33—Brome-grass, 33—Redtop, 33—Orchard- grass, 33—Meadow fescue, 33—Rye grasses, 33— Southern pasture-grasses, 35—-Two common tropical grasses, 35. Temporary pasture .. oie 1 aOo iF rr Annual plants for pee 36. CHAPTER V MeEapow PuANts. . . SO EES Ss Sy Native meadows, 38-—The commercial production of wild hay, 39—Salt-marsh grass, 40—Tame meadows, 40—Permanent meadows, 40—Alfalfa (Medicago sativa L.), 41—Clovers, 41—Timothy, 42—Redtop, 43— Johnson-grass, 43—Eradication of Johnson-grass, 44— Other meadow-grasses, 45—Slender wheat-grass, 45— Temporary meadows, 46—Grain hay, 46—The relative importance of grain hay, 46—Millets, 47—Sorghum; 48—Corn, 48—Other grasses producing hay or coarse fodder, 49—Japanese barnyard millet, 49—Proso millet, 50—Pearl millet, 50—Legumes, 50—Cowpea (Vigna sinensis (Torner) Savi), 51—Velvet bean (Stizolobium Deeringianum Bort), 52—Vetches, 52—Other legumes, 52. CHAPTER VI Hay AND GREEN FEED .. . 54-60 Hay, 54—In arid regions, 55—Stacks, 55—Hay in a. West, 56—The standard hay, 56—Baled hay, 56—Soiling and silage crops, 57—Soiling, 57—Silage, 58, TABLE OF CONTENTS ix CHAPTER VII reg eC ft ee Pes 28> en Aes Le Ss ISBT Essentials for a lawn, 61—Blue-grass, 61—Rhode Island bent, 62—Bermuda-grass, 62—Less important lawn- grasses, 63—Lawn mixtures, 64—Preparation of the soil, 65—Seeding, 65—Subsequent care, 66—Watering, 66—Turfing, 67. CHAPTER VIII Grasses USED FOR MISCELLANEOUS PURPOSES . . ... 68-74 Ornamental grasses, 68—The bamboos, 69—Soil- binding, 69—Sand-dunes, 69—Reclaiming sand-dunes, 70—Sand-binders, 71—Fixing sand with beach-grass, 71—Sugar-producing grasses, 72—Sugar-cane, 72— Sorgho or sorghum, 73—Textile grasses, 73—Other uses, 74—Green-manuring, 74. CHAPTER IX Rr ef ke eee gig STS Ak oe Classes of weeds, 75—Perennial weeds, 76—Weedy grasses, 76—Annual weeds, 76—On the Pacific coast, 77—Perennial weedy grasses, 77—The seriously trouble- some weeds, 78. CHAPTER X SEOs AABEAGS Sey ko isl ge pele a OS OESE Moisture, 77—Temperature, 79—The timothy area, 80— The Bermuda-grass area, 81—The Great Plains, 81— Forage crops for the Great Plains, 82—The arid section, 83—The Pacific slope, 84—The relative importance of the different kinds of forage in the different regions of the United States, 84—Remarks on Table XVII, 85. x TABLE OF CONTENTS PART SYSTEMATIC AGROSTOLOGY CHAPTER XI PaGEs MoRPHOLOGY OF THE VEGETATIVE ORGANS ... .. .95-111 Distinguishing characters of grasses, 95—Gross anatomy, 96—Perennial herbaceous species, 96—Distribution, 97— The root, 98—The stem, 98—Duration, 99—Stems modi- fied for propagation, 100—Stolons, 101—Corms, 102— Artificial propagation by means of stems, 102—The leaf, 103—Leaf-base and blades, 104—The prophyllum, 104— The sheath, 104—Sheath-nodes, 105—The collar, 105— The ligule, 105—The blade, 106—Nervation, 107— Auricles, 108—Roll leaves, 108—Scales, 109—Bracts, 110. CHAPTER XII MoRPHOLOGY OF THE FLORAL OrGANS ... . . «112-132 The inflorescence, 112—Kinds of inflorescence, 113— Unisexual inflorescence, 114—Moneecious genera, 115— The axis of inflorescence, 115—Branching of panicles, 116—Motor organs, 117—The spikelet, 117—Sterile spikelets, 120—The pedicel, 120—The glumes, 121— Anomalous glumes, 123—The lemma, 124—Sterile flo- rets and sterile lemmas, 125—Awns, 126—Twisted awns, 127—The palea, 127—The lodicules, 128—The stamens, 128—The pistil, 129—The fruit, 129—The seed, 130— The embryo, 131—The endosperm, 131—The rachilla, 131. CHAPTER XIII TUCOTIMEIIT 3s. cas) eh) alee ie Cel Seed dispersal, 133—Dispersal by wind, 133—Dispersal by animals, 135—Germination, 136—Germination of TABLE OF CONTENTS xl PAGE maize, 136—Impervious seed-coverings, 137—Self-burial, 137—Water-grasses, 138—Propagation by bulblets, 139 —Plant societies, 139—Mesophytes, 140—Xerophytes, 141—Prairie, 142—Sandy soil, 143—Sand-dunes, 143— Pine-barrens, 144—Rocks, 144—Deserts, 144—Halo- phytes, 146—Hydrophytes, 146—Geographical dis- tribution, 147—Distribution of grasses, 148—Distri- bution of species, 148—Circumpolar distribution, 149— Generic distribution, 149. CHAPTER XIV TAXONOMY OR CLASSIFICATION. . . . . . . . 151-158 Species, 151—Genera, 152—The grass family and its subdivisions, 154—The two series of tribes, 154—The tribes of grasses, 155—The more important genera of grasses, 156—Characters used in classification, 157— Phylogeny, 157. CHAPTER XV ren ROMIRIE J lk lw ee Ck el SOS Tripsacum L., 159—Euchlena Schrad., 160—Zea L., 161—Coiz L., 162. CHAPTER XVI TriseE I]. Andropogonee . . «eae t ABS Miscanthus Anderss., 166—Saccharum L., 166—Eri- anthus Michx., 167—Subtribe Huandropogonex, 167— Andropogon L., 169—Cymbopogon Spreng., 169—Holcus L., 170—Classification of the sorghums, 172—Tribe III. Naziex (Zoysiex), 173—Tribe IV. Melinidex (Triste- ginex), 175. xii TABLE OF CONTENTS CHAPTER XVII PaGEs Trimet V.. Pantter . .. . 3) . Dia Paspalum L., 175 Aadegde inion 180-—Syntheriema Walt., i) SPadarun GB. 181—-Belinochloa Beauv., 183— Tricholzena Schrad., 184—-Chztochies Seribn., 184— Pennisetum Pers., 186—Cenchrus L., 187—Stenotaphrum Trin., 187. CHAPTER XVIII Trips VI. Oryzexr . . os: =e Oryza L., Gs ens aa Te 191. CHAPTER XIX Tayern Vil. Phalaridee . ... . +. «2° =) See Savastana Schrank, 192—Anthoranthum L., 193— Phalaris L., 194. CHAPTER XX TriseE VIII. Agrostidex ax . . . ae Aristida L., 199—Stipa L., 199 -M shiooilents Schreb., 200—Phleum L., 20 Abamocunas L., 202—Agrostis L., Mie Calamagrostia Adans., 6 Aaemo ane Hose 206—Lagurus L., 207. CHAPTER XXI Trips IX... Avenee .. i. . «Zi Notholcus Nash, se eae L. -209—Origin of the cul- tivated oats, Bib: Arphenctharae Beauv., 212. TABLE OF CONTENTS xill CHAPTER XXII Paces mare &. Chiorider >. : -. oe 9) eee Capriola Adans., 214—Chloris ‘ehanx 216-—Bouteloua Lag., 216—Bulbilis Raf., 218. CHAPTER XXIII eee. Mesiueee.. ws ee og. te Bee Cortaderia Stapf, 224—Arundo L., ae ee Host, 225—Distichlis Raf., 225—Dactylis L., 226—Poa L., 227—Kentucky blue-grass (P. fies ANY L.), 228— Other economic species of Poa, 229—Festuca L., 230— Meadow fescue, 230—Sheep’s fescue (F. ovina L.), 231— Red fescue (F. rubra L.), 231—Bromus L., 232—-Awnless brome-grass, 232—Rescue-grass (B. unioloides Kunth), 233. CHAPTER XXIV Tripe XII. Hordex A ch het fect ees : Gaeme kee Lolium L., 236—Agropyron peg 237—Triticum Lie 238—Spelt and emmer, 239—Origin of wheat, 240— Classification of the wheats, 242—Secale L., 244— Hordeum L., 244—Elymus L., 246—Tribe XIII. Bambu- sex, 247. CHAPTER XXV NOMENCLATURE... ; 4 2eR=266 Generic names, 250-—Specific names, 251—N ouns in the genitive, 252—Nouns in apposition, 252—Names of a lower category, 253—Transferring specific names, 253—Authors of names, 254—Use of parentheses, 254— Capitalization, 255—Bibliography, 256—Valid names and synonyms, 257—Codes of botanical nomenclature, 258—Vienna code, 258—American code, 259—Compari- son of the two recent codes, 260—Common names, 260— List of books and articles relating to taxonomic agros- tology, 262. Fic. . Production of hay and forage in the United States. One large 15. 16. LIST OF ILLUSTRATIONS PaGE dot represents 500,000 tons; one small dot represents 100,000 . Production of timothy in the United States. One dot represents MOTT ERE oe eine CAR San cna rad thd ara wig Mipee ies g aterm ip axe ees . Production of timothy and clover mixed in the United States. ae watrepresents: 100:000 tons... . so Uo cbs cose oes . Production of clover alone in the United States. One dot rep- Rem ena Sy OPC CMO RITE So o5 spre a Sere a att pe Woes oe Eels Cee . Production of alfalfa in the United States. One dot represents ENNIS fa Ss Setar Gera g aok clog oe oss Pw afte OER al oie Seni rae . Production of millet and Hungarian-grass in the United States. Meera TEPRESENTS B2UUU TONE. - ot ojo utes G oie oe Silene ca Che ae . Production of other tame and cultivated grasses in the United States. One dot represents 10,000 tons.............e00sec< . Production of wild, salt and prairie grasses in the United Soaces. One dot represents 10;000 tons... 7... . osc eckson . Production of grains cut green in the United States. One dot ean EES PVE UNUMD ERTISS 0S 2, ce alas siege Ace Glee s: tale keer es oe ee . Production of coarse forage in the United States. One dot rep- (DEES Sen C80 Ag G2) 1s Omg a age ec Rt AS) . Euchlena mexicana. Portion of plant reduced; a pistillate in- florescence, and four fertile spikelets. (U.S. Dept. Agr. Div. 2 SE ET (OR |) ee et ee er Rn A CR SR, a Ba . Coix lacryma-Jobi. Inflorescence showing several pistillate beads, the staminate spikes protruding: x% ............... . Miscanthus sinensis. Plant much reduced; spikelet, x 3. (U.S. ivene nee Diy. Aerogh, vesisls ING: 20). .3 05.0. « aaeecbne aie . Saccharum officinarum. Plant much reduced; three joints of the rachis (a), a spikelet (6), and a flower (c), x3. (U.S. Beowsaer, diy. Arrost: Bull, No; 20)n:.). 3. vee cess ue ek: Erianthus divaricatus. Plant reduced; spikelet, flower, the two glumes, and the fertile lemma with lower portion of awn. io, 8. Dept. Agr. Div. Agrost. Bull. No. 17)i0. 02.066 ec ax oss Andropogon fureatus. Inflorescence, X14. A joint of the rachis with a fertile spikelet below and a staminate spikelet above, «5. (xv) 14 15 15 16 16 18 18 19 20 20 160 162 166 167 168 169 Xvi Fia. ie 18. 39. 40. LIST OF ILLUSTRATIONS Pace Holcus halepensis. Inflorescence and rhizomes, x 44; a terminal fertile spikelet with two staminate spikelets, X3 ........... 171 Hilaria cenchroides. Plant reduced; group of spikelets, a staminate spikelet, a pistillate spikelet, x 5. (U. S. Dept. Agr. Div. Agrost. Bull. Now20) 0.25 622.) 12. sat oe eee eee 174 . Paspalum dilatatum. Inflorescence, x 4; spikelet X5......... 179 . Syntherisma sanguinalis. Plant, x 144; two views of spikelet, x5. 180 . Panicum miliaceum. Inflorescence, x 2%; spikelet and fruit (fertile lemomia and palea), x 7... 05.0255 > 2. a ee 182 . Echinochloa frumentacea. Inflorescence, x 4; spikelet, X5... 183 . Chetochloa lutescens. Inflorescence, x 34; spikelet with sub- tendine bristles; X52 be os da debe va Sob ye 184 . Chetochloa italica, Hungarian-grass. Inflorescence, K 34 ...... 185 . Cheetochloa italica, common millet. Inflorescence, x 14; fruit x 5. 185 . Pennisetum glaucum. Inflorescence, X 14; spikelet with in- volrcre of bristles, < 5. ..e.5 3. kbs oc eee eee ee 186 . Cenchrus carolinianus. Upper portion of plant with inflor- escence, >< 39; spikelet, X 7.....0650. 40.0.0 2sn 5 oe a 187 . Stenotaphrum secundatum. Upper portion of culms with inflorescence, 14; spikelet,; 5 oi... oc. we ee bg os a 188 . Pharus glaber. Plant reduced; branchlet of inflorescence with a sessile pistillate and pedicelled staminate spikelet, and a fertile floret. (U.S. Dept. Agr. Div. Agrost.,Bull No. 20)... 189 . Oryza sativa. Inflorescence, X 14; spikelet, X3.............. 191 . Zizania palustris. Inflorescence, much reduced. (U. 8S. Dept. Agr. Div. Agrost. Bull.. No. 34)e:.. oo 5 0G. i< ee ee 191 . Anthoxanthum odoratum. Inflorescence, x 1; spikelet, the two sterile lemmas and the fertile floret, X 5..............2020- 192 . Phalaris arundinacea. Inflorescence, X 4%; spikelet and fertile i(c) 92) aD Gi ho Dian een eMen OE eke SR 193 . Phalaris canariensis. Inflorescence, X14; glumes and fertile floret with the pair of sterile lemmas, * 5.................. 194 . Aristida longiseta. Spikelet, the fertile lemma raised from the layne XK 1s oo oa on ken oe we wie bvelw bie 3 eo Ole ae 199 . Stipa spartea. Mature fertile lemma (fruit) with twisted awn, X1. 200 . Muhlenbergia gracilis. Plant, x14; spikelet, the floret raised from the glumes; glumes and floret. (U. S. Dept. Agr. Div. Bot. Bull, No. 26)... 35s 3. eee ew oe Boe ee 201 . Phleum pratense. Inflorescence, X 4%; glumes and mature POTEG OS oo ois an 5 spn nen wipe win Gow mre wa pee ere 202 Alopecurus pratensis. Plant reduced; spikelet and floret. (U..8. Dept. Agr. Div. Agrost. Bull. No. 20).......°.seeaus 203 Agrostis alba. Inflorescence and rhizomes, X%4; spikelet, x 5.. 204 Fia. 41. LIST OF ILLUSTRATIONS XVli PaGcE Calamagrostis scabra. Plant reduced; spikelet, the floret raised from the glumes. (U.S. Dept. Agr. Div. Agrost. Bull. RMON ERs et se eon eit dek PAS VO a OE Ld Be 205 42. Ammophila arenaria. Inflorescence and lower portion of plant, x4. (U.S. Dept. Agr. Div. Agrost. Buli No. 14).......... 206 43. Notholcus lanatus. Inflorescence, X%; spikelet, the two Hoerets. raised ‘from the elumes, 4 © «5 5 655 o Sen diwnlc See oss 210 44, Avena fatua. Spikelet and a lower floret, X1............000- 211 45. Arrhenatherum elatius. Inflorescence, X14; spikelet, X4....... 212 46. Capriola Dactylon. Plant showing stolons, X23; spikelet, X7. 215 47. Bouteloua gracilis. Inflorescence, X 1; spikelet, X 10.......... 216 48. Bulbilis dactyloides. Staminate plant, x 14; spikelet, X4...... paw 49. Bulbilis dactyloides. Pistillate plant, x 4%; cluster of spikelets 61. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. RaRMED EERE os OA! 3h Oe eral oa Meecha, ated alee Siete am i earch aca) teh 218 . Cortaderia argentea. A group of inflorescences greatly reduced; glumes of pistillate spikelet (a), florets of pistillate spikelet, (b) glumes (c), and florets (d) of staminate spikelet. (U. S. Bet Ase. Div. Asrost. bulk Ne. 20}oc.eties. s5cu oboe wees 224 Eragrostis cilianensis. Plant, reduced; two spikelets, showing variable number of florets; portion of rachilla from which some of the florets have fallen. (U. S. Dept. Agr. Div. Perea t EVENT ES GP 355 cls co eis cae ae as eo Bas atte of Rw Se ayers 225 Distichlis spicata. Staminate plant (at left) and pistillate plant (at right) reduced; pistillate and staminate spikelets... 226 Dactylis glomerata. Inflorescence, X24; spikelet, X7......... 228 Poa pratensis. Plant, X 4%; spikelet and floret, X5........... 229 Festuca elatior. Inflorescence, x 4%; spikelet, K4............. 231 Bromus inermis. Inflorescence, X 4%; spikelet, X3............ 233 Lolium multiflorum. Inflorescence, X 14; spikelet, with portion SMES SOG 7 PO ee a ih atone wid alg) tm eae Sa Wahi ae a gee are 237 Agropyron repens. Inflorescence and rhizomes, X 14; spikelet, Pa ey cee ee ie he Ia Sa aia Cae bin fate eesti 238 Triticum dicoccum. Inflorescence (head), X 14; spikelet with a disarticulated joint of the rachis, X 2.......00.--seceeees 239 Triticum xstivum. Inflorescence (head), X 1%; spikelet with MOrMOn-O! abtaAcned EACRIS, M2 ois 6s SEES Sain eo ka wees 241 Secale cereale. Inflorescence (head), X14; spikelet, x 2........ 244 Hordeum vulgare. Inflorescence (head), X14; cluster of 3 spikelets, and a single floret from the back showing the Partin renee bt eS, Lice bs ta we oo anta Sis aiden ate 245 Arundinaria macrosperma. Portion of culm with inflorescence reduced; floret, palea showing lodicules, and a caryopsis, reduced. (U.S. Dept. Agr. Div. Agrost. Bull. No. 20)...... 248 PART 1 ECONOMIC AGROSTOLOGY A TEXT-BOOK OF GRASSES CHAPTER I INTRODUCTION Economic botany is that branch of the science of botany which treats of the uses of plants. All animals, man included, are dependent directly or indirectly upon plants for their existence. With the exception of water and a small amount of mineral matter such as salt, the food- supply of all animal life finally may be traced back to the constructive metabolism of plants, a process depend- ent upon photosynthesis. Many animals derive a whole or a part of their food from other animals, but sooner or later in the chain of relations between animals and their food-supply a point is reached where the ultimate deriva- tion is from plants. The vegetable kingdom provides directly a large part of the food for man and for his domestic animals. It provides the fibers from which much of his clothing is made; much of the material for construct- ing his home and the articles with which it is furnished; many of the drugs, medicines, dyes, condiments, bever- ages, and a great variety of other useful articles or substances. . Of the natural families of plants that contribute their quota to supply the wants of man, the grass family exceeds all others in the amount and value of its products. To A (1) 2 A TEXT-BOOK OF GRASSES this family belong the grains, such as wheat, corn, and rice, that furnish the bulk of the vegetable food of the world for man, and feed for stock; the greater part of the pasture and meadow plants that furnish forage and hay; and many large grasses such as the sugar-cane, the sor- ghum, and the bamboos that are not usually classed with this family by those who are not botanists. 1. Agrostology—Agrostology is that branch of botany which treats of grasses. The term is derived from two Greek words, agrostis (@ypostis from 4aypés, a field) a kind of grass, and logos (Aoyos) speech. The subject is usually divided into two branches, economic agrostology and systematic agrostology. Like any other branch of botany, agrostology can be considered also from the standpoint of anatomy, morphology, or physiology. Up to the present time the study of grasses from these stand- points has not received distinctive recognition but has been merged with the anatomy, morphology, and physiol- ogy of plants in general, or has been included in syste- matic agrostology. 2. Economic agrostology.—This is that branch of economic botany which treats of grasses, or it is that branch of agrostology which treats of the uses of grasses. The uses of the grasses and their products are so many and various and touch so many industries that it is necessary to define the limits of the subject as it will be considered in this work. It is intended so far as practicable to restrict the discussion of economic agrostology to its botanical phases. The methods of growing grasses, that is, cultural methods, belong more properly, in case of the field crops, to agronomy; or, in case of the ornamental species to horticulture. The methods of obtaining the products of grasses and the course of the products after INTRODUCTION 3 they leave the plant, such as the extraction of sugar from sugar-cane, or the threshing of grain and its subsequent conversion into flour and bread or into starch or alcohol, may belong to chemical technology. In the present work it is proposed to emphasize the botany connected with the economic phases of agrostology, but information will not be excluded from brief mention when necessary for a proper understanding of the subject, even though this information would fall naturally under some allied branch such as agronomy. 3. Systematic agrostology—tSystematic agrostology treats of grasses from the botanical as distinguished from _the practical or economic side. Strictly speaking system- atic agrostology should be synonymous with taxonomic agrostology; that is, it should concern itself with the botanical classification or natural relationship of grasses. In the present work it includes also such morphology as is necessary for a proper understanding of. classification and also brief references to ecology and some general information less easily classified. 4. The uses of grasses.—In a future chapter grasses are technically defined and distinguished from other plants. The term grass is generally understood to include herbaceous plants with narrow leaves, such as timothy, blue-grass, and redtop. The farmer often understands by grass any small herbaceous plant, especially such as is used for forage. In this sense he includes among the grasses such leguminous plants as alfalfa and clover. There are a number of plants with narrow, grass-like leaves that also may be confused with the grasses. Among such plants are the sedges, rushes, and certain lilies or lily allies. On the other hand the layman may not recog- nize as grasses the larger members of the family, such as 4 A TEXT-BOOK OF GRASSES corn, sugar-cane, the giant reed, and the bamboos. In the popular mind even the grains may be excluded from the idea of grasses. Without introducing at this point the exact botanical definition of a grass, it may be said that grasses include such representative plants as timo- thy, wheat, corn, sugar-cane and bamboos, but exclude the clovers, the sedges, and the rushes. 5. The value of farm crops.——The total value of all crops produced in the United States in 1909 was $5,487,- 161,000.* In this respect, Illinois leads among the states. The following table gives the relative rank of the first ten states: TABLE I ToraL VALUE (DoxtiaRs) oF ALL Farm Crops In 1909 FoR THE TEN LEADING STATES aD aries) e's of icieal $372,270,470 6. Missouri . . .$220,663,724 CASE TOD re Se ee 314,666,298 7. Kansas ... . 214859509 Spee Res 2 SA eae 298,133,466 8. New York .. . 209,168,236 os O10 ea 230,337,981 9. Indiana ... . 204,209,812 7 Gy eo 226,595,436 10. Nebraska ... a The total value of the leading crops indicates the relative importance of those derived from the grass family as compared with those from other families: TABLE II ToTaL VALUE (DOLLARS) OF THE LEADING Crops IN 1909 Cereals ... . SUS aA MASS BAAS ©, ES Hay and forage SBCA TWh to ara rakrnae: yates sa 824,004,877 Tobacco .. MAMAS RC TIRANA BOE eC SC Cotton and eohiane abe OS Date Bak, Bee SIRE PCTODIS). 07 oS. ee cease um ed ee ee 61,648,942 Moarendbled |< h e oa al dae a pee ee Ie, ee Fruits and nuts .. 5 ee, ea sl Od ink 7s eae Forest products of farms. hs RET eS A 0 The total valuation in Table I does not include forest products except such as are produced on farms. The *The statistics of this and other tables are taken from the Thirteenth Census of the United States, Vol. V INTRODUCTION 5 value of cereals includes that of buckwheat ($9,330,592), which is not a grass. To the value of hay and forage might be added that of grass seed ($15,137,683) classed under ‘‘other grains and seeds.” Under ‘‘vegetables’’ is included potatoes as the most important single crop. It will be observed from Table II that the value of | cereals is about 48 per cent, of hay and forage 15 per cent, and of cotton 15 per cent, of the total value of all farm crops. By including grass seed, broom-corn, sorghum, and sugar-cane, and excluding buckwheat, it is found that about 641% per cent of the value of farm crops is derived from members of the grass family. The value of hay and forage does not include that of pasture and range, which if taken into consideration would swell enormously the total value of the products of the grass family. CHAPTER II ECONOMIC CLASSIFICATION OF GRASSES ACCORDING to their uses, grasses may be classified into three main divisions,—grains, forage plants and lawn grasses; and four minor divisions,—ornamentals, soil- binders, sugar-producing grasses, and textile grasses, leaving a few unclassified. Another category of grasses, the weeds, being the antithesis of useful plants, might be included under economic grasses. A special chapter is devoted to them (Chapter EX). GRAINS 6. The term grain is applied to those grasses whose fruit is used for food or for stock-feed. The fruit or seed is technically a caryopsis (Par. 162), or in popular lan- guage, a grain. The common grains are corn, sorghum, wheat, rye, barley, oats, rice, millet. 7. Uses of the grains for food.——The seeds are rich in starch and usually contain also a considerable quantity of protein. For this reason they are eminently fitted for use as food. In the United States, the grain of sorghum and millet is not used for human food, although both are extensively used for this purpose in some parts of the Old World, especially among primitive peoples. Oats, rye and barley, though used to a limited extent, are of secon- dary importance as food plants in America. The other three grains, wheat, corn, and rice, are of fundamental (6) ECONOMIC CLASSIFICATION OF GRASSES 7 importance as food plants for the white race both in America and the Old World. Wheat, oats, barley, and rye are usually designated by the American farmer as small grains, to distinguish them from corn. Rice is usually not included in this loose classification because its culture is confined to the moist regions of the coast, and it is not found in the grain-growing districts of the country. Emmer, spelt, and other species of wheat allied to our common bread wheat, are grown in the Old World, and the first mentioned is grown to a limited extent as a forage crop in America. (See Farmers’ Bul- letins Nos. 139, 466.) A classification of the grains with their botanical names is given in a future chapter. All the grains cultivated in the United States are annuals. Certain plants that belong to other families are cultivated in various parts of the world for the seed which is ground into flour and used for food, and hence might be classed as grains. The only one of these used in this country is the buckwheat (Fagopyrum esculentum L.). Certain others are cultivated among primitive peoples in other parts of the world, as for example, the quinoa (Chenopodium Quinoa Willd.) in the Andes. The seeds of certain wild grasses, especially the Indian rice (Zizania palustris), have been used by the North American Indians for food. 8. Relative importance of the different grains.—The grains are used primarily for human food. Scarcely less important is their use as feed for domestic animals. Wheat and rice are used almost exclusively as human food, but all the others are used in part or, in the United States, almost wholly for stock feed. In Europe, to a much greater extent than in America, barley and rye serve as bread- stuffs, while millet (Chetochloa italica) and proso millet 8 A TEXT-BOOK OF GRASSES (Panicum miliaceum) are used for porridge or mush. In America the latter grains are fed to stock only. Certain varieties of sorghum furnish an important part of the human food-supply in Africa and China, while in this country other varieties, such as kafir, are used as stock feed. .The most important grain is wheat, which is nearly all made into flour, forming the principal breadstuff. Corn is next in importance, furnishing a large part of the feed of domestic animals and serving also to a considerable extent for human food. Oats are produced chiefly for feeding horses, though some goes into oatmeal for human food. In this country barley is raised chiefly in the cooler regions, and is of importance as a food for stock in those regions where, because of. the short growing season or for other reasons, corn cannot be successfully grown, as in much of the West and Northwest. Large quantities are also used in the brewing industry. Rye as a grain is of comparatively little importance in the United States. Rice is of secondary importance in America because, requiring for its cultivation a warm climate and land that can be flooded, the area adapted to its growth is limited in extent, being confined to the low coastal region from North Carolina to eastern Texas. A variety known as upland rice is being grown in Louisiana and eastern Texas on drier land and is cultivated and harvested in the same manner as wheat. In the warmer parts of the Old World, especially in southeastern Asia, rice is the most important food plant grown. 9. Value and production of the cereals.—The value of the different cereals produced in the United States in 1909, excluding buckwheat, is shown in the following table: ECONOMIC CLASSIFICATION OF GRASSES 9 TABLE III Tue VALUE (Do.uars) oF CEREALS IN 1909 MOE ec ass a fel 4, OOS, 01O | Rye. we 6 we. 20,421,812 ete c. 4a. -. Ss) GSR, BSG,SOl- ! ae 26.7. 8! aS SOLS GOT ate =... .'°.°. .. 4). 414,697,422 Kafir and Milo... . 10,816,940 Barley ..... . . 92,458,571 Emmerand Spelt .. .5,584,050 The production of cereals in the United States as compared with the total world production: is shown in Table IV (see Farmers’ Bulletin No. 581): TABLE IV PRODUCTION (BUSHELS) OF THE CEREALS FOR THE UNITED STATES AND FOR THE WORLD IN 1913 United States World nes 21. . 62446998 000) Com —2 Ns 3 S67 S58.000 Hes . . . ; «>: °763;590,000. Wheat. ..: .-.:. 4,126,000,000 Dee Sis ts | ie DA ee eee. Oat so Soi olen: ae mares... . .. . 178,189,000 Barley.) 2 .. ...° 1,613,7438,000 Peet ie) ola os ARS OOO... Figo’ Sac ae. 3 ES It is seen from this table that the United States pro- duced about two-thirds of the corn, one-fifth of the wheat, and one-fourth of the oats of the world, but only a small part of the barley and rye. Other countries leading in the production of corn are Argentina, Hungary and Mexico; of wheat, Russia, Brit- ish India, France and Canada; of oats, Russia, Germany, Canada and France; of barley, Russia, Germany and Japan; of rye, Russia, Germany and Austria. The value of the cereals produced by the ten leading states is shown in Table V: TABLE V THE VALUE (DOLLARS) OF THE CEREALS PRODUCED IN 1909 BY THE TEN LEADING STATES Fimo”... ': °.§297,523,098 6. North Dakota .$149,133,451 oe 230,205,315 7. Missouri . . . . 147,980,414 3. Kansas ... . . 169,109,449 8. Minnesota . . . 140,864,148 4. Nebraska ... . 153,666,652 9. Ch oe. ol SE SOT Set 5. Indiana . . . . . 151,898,146 10. South Dakota. . 98,953,050 10 A TEXT-BOOK OF GRASSES TABLE VI PRODUCTION (BUSHELS) OF CORN FOR THE Five LEADING STATES IN 1909 1:- Timois® . ...-.. . 390,218,676 4. Missourl . . . © “S904 2, lowa > . .. . . 341,750,460 95. Nebrasks .-. .. J1S0ig2e 3. Indiana... . . . 195,496,433 TABLE VII PRopuctTION (BUSHELS) OF WHEAT FOR THE FIvE LEADING STATES IN 1909 1. North Dakota . .116,781,886 4. Nebraska ... . 47,685,745 Sa Aansas . . . . . @6,004,11b 6. South Dakota .°. 47-0saeee 3. Minnesota .. . . 57,094,412 TABLE VIII PRODUCTION (BUSHELS) OF OATS FOR THE FIVE LEADING STATEs IN 1909 1. Illinois . « » . 150,386,074 . 4. Wisconsin. ...... . @ija=eeae 2. fewa . . =.» « 128,198,055 5. North Dakota—... 65:33h- 000 o. Wemnescta «. . .°93,897,717 TABLE IX PRODUCTION (BUSHELS) OF BARLEY FOR THE FiIvE LEADING STATES IN 1909 1. Mimnesota .. .. 384,927,773 4. South Dakota .. 22,396,140 2. California .. . . 26,441,954 5. Wisconsin ... - 22,156 eee 3. North Dakota .. 26,365,758 TABLE X PRopucTION (BUSHELS) OF RYE FOR THE Five LEADING STATES IN 1909 1. Michigan... . . 5,814,394 4. Pennsylvania ... 3,496,603 2: Wisconsin. .-.°.. 4,797,775 5. New York . . . < 20a 3. Minnesota ... . 4,426,028 TABLE XI PRODUCTION (BUSHELS) OF EMMER AND SPELT FOR THE FIVE LEADING STATES IN 1909 1. South Dakota... . 6,098,982. #4. Kansas..... . .:. .° 78eeaee 2. North Dakota... 2,564,732 .5.Mimnesota ... .. « @eneeee an tuebraska:: 42) . 0,221.97 The production of grain from kafir and milo is indicated in Table XII. The statistics for these crops when grown for forage are included under “coarse forage: ECONOMIC CLASSIFICATION OF GRASSES 11 TABLE XII PrRopUCTION (BUSHELS) OF GRAIN OF KaFIR AND MILO FOR THE FIVE LEADING STATES IN 1909 Lok Gos 5,860,444 4. California ..... 938,049 “ay in: ae 5,115,415 5. New Mexico .°. . .. 543,000 3. Oklahoma .. . . 4,658,752 The production of rice has shifted in recent years from the South Atlantic coast to Louisiana and Texas, where upland rice is now grown. Over nine-tenths of the acreage of this crop is now in the two last- mentioned states: TABLE XIII PRODUCTION (BUSHELS) OF RouGcH RIcE FOR THE FIVE LEADING STATES IN 1909 me Woaasiagis . 4. 2s 10,839,973 4. South Carolina .. . 541,570 og Rake: i rao 2k De Sea ge © 2) ns: a me 148,698 Bee iCtAAS 57S Les 1,282,830 STARCH 10. All the grains mentioned may be used for the pro- duction of starch and alcohol—From the commercial standpoint, the chief starch-producing plants of the world are corn, wheat, rice, potatoes and arrow-root. Wheat is usually too valuable a human food to be used for any other purpose. Corn is the chief source of starch in the United States, although the other grains may be used when available. In the manufacture of starch from corn, the grain is soaked but not allowed to ferment. The softened kernels are then ground in water and the starch purified. A bushel of corn will yield twenty-eight pounds of starch and thirteen pounds of refuse available as cattle food. In Europe the potato is the chief source of starch. 12 A TEXT-BOOK OF GRASSES ALCOHOL 11. Another important product of the grains is alco- hol—For this purpose the starch is first converted by means of diastase into maltose, a kind of sugar, and the sugar is fermented by means of a yeast plant. The fer- mented liquor is distilled, the product being alcohol. The diastase is an unorganized ferment present in the germi- nating grains. This converts the stored starch of the seed into a soluble form, a sugar, which can be absorbed by the young plant. The grain to be used as a source of alcohol is allowed to germinate, is heated to kill the embryos, and is then fermented with yeast. This con- verts the sugar into alcohol and carbon dioxide. If beer is the product desired, barley is the grain usually employed and the process is stopped at this point. If a distilled liquor is desired, the material is distilled. The details of the manufacture of the various alcoholic products belong to the study of industrial chemistry. Wine is produced by fermentation from the juices of fruits containing sugar, especially the juice of the grape. This liquid, when dis- tilled, produces a brandy. MISCELLANEOUS USES OF THE GRAINS 12. In the manufacture of starch or alcohol, the grains furnish many other substances, often as by-products. Among these may be mentioned gluten meal and corn oil, the one from the protein and the other from the fat of the seed. Corn oil is expressed from the grain before the starch is extracted, or it is obtained from the residue in the fermentation vats in the manufacture of alcohol. Much of the commercial vinegar is produced from malt ECONOMIC CLASSIFICATION OF GRASSES 13 liquor, the alcohol being converted into acetic acid by means of ferments. Besides being used for the production of seed, the grasses mentioned above are extensively used for forage, a use which will be discussed in a future chap- ter. Corn in one of its varieties or species, sweet corn, is commonly used as a vegetable, the kernels being cooked when in the milk stage. Other varieties are cultivated for ornament and for pop-corn. The pith of the stalks of field corn has been used for many purposes, especially those involving the production of pure cellulose. CHAPTER IIT FORAGE PLANTS ScARCELY less important than the use of grasses for the production of human food is their use for forage. The domestic animals, upon which man depends in part for his food, in their turn depend upon wild or cultivated forage plants. Tr eheheteteten 2 Fie. 1. Production of hay and forage in the United States. One large dot repre- sents 500,000 tons; one small dot represents 100,000 tons. 13. The importance of forage plants is shown in part by the statistics given in the census report under the heading “hay and forage,” which includes plants cut and used dry or green for forage, but does not include plants used for pasturage. The figures also include an insig- (14) 15 FORAGE PLANTS ' ‘ ! ' ' ' 4 ‘ 000 tons. Production of timothy in the United States. One dot represents 100 Fig. 2. = - - -=- Fig. 3. Production of timoth y and clover mixed in the United States. One dot epresents 100,000 tons. r A TEXT-BOOK OF GRASSES 16 — One dot represents Fie. 4. Production of clover alone in the United States. 10,000 tons. One dot represents Production of alfalfa in the United States. 5. Fig. 20,000 tons. FORAGE PLANTS 17 nificant amount of root forage. The total acreage in 1909 is given as 72,280,776, which produced 97,453,735 tons of forage valued at $824,004,877. The value of hay and forage as compared with other crops is shown in Table Mo Par..5). The statistics partially classify the hay and forage as follows: TABLE XIV ACREAGE, PRODUCTION, AND VALUE OF Hay AND ForRAGE FoR 1909 BY CLASSES hase ue cee | ee | Timothy alone ~ 14,686,393 17,985,420 $188,082,895 Timothy and Clover feet oS tL eae 748 555 257,280,330 Clover alone . 2,443,263 3,158,324 29,334,356 Alfalfa x4 4,707,146 11,859,881 | 93,103,998 Millet or Hungarian / grass. . | 1,117,769 1,546,533 | 11,145,226 Other tame or culti- | : | vated grasses .. .| 4,218,957 4,166,772 44,408,775 Wild, salt or prairie grasses Bid heleg 17,186,522 18,383,574 91,026,169 Grains cut ae 4,324,878 5,367,292 61,686,131 Coarse forage 4,034,432 | 9,982,305 46,753,262 The production of hay and forage of the ten leading states is shown in Table XV. The production of all the states is graphically shown in Fig. 1. TABLE XV Propuction (Tons) of Hay anp ForRAGE OF THE TEN LEADING States IN 1909 B, tows . . . . . . 7,823,181 6. Wisconsin . 5,002,644 2. New Vark . £,055,429 7. Ohio . 4,521,409 3. Minnesota . 6,036,747 ‘8. Illinois , . 4,354,466 4. Kansas : . 5,936,997 9. California. . . 4,827,130 5. Nebraska . . 5,776,475 10. Missouri . 4,091,342 A TEXT-BOOK OF GRASSES 18 mee Fia. 6. Production of millet or Hungarian grass in the United States. One dot represents 5,000 tons. Fig. 7. Production of other tame or cultivated grasses in the United States ne dot represents 10,000 tons. FORAGE PLANTS 19 NATURAL CLASSIFICATION 14. In order to show the relative position of grasses among forage plants, a classification is here given based upon botanical relationships. Forage plants may be divided into three groups. These are: grasses, legumes, miscellaneous plants. The first group includes plants belonging to the grass family (Par. 118). Fig. 8. Production of wild, salt or prairie grasses in the United States. One dot represents 10,000 tons. 15. Legumes.—The second group includes those belonging to the natural family Leguminose or Fabacee. The plants of this family are characterized by the fruit, which is a legume or pod. To this family belong the clovers, alfalfa, vetches, beans, peas, and many similar plants. The importance of legumes as forage plants depends upon their high protein content, and hence their greater nutritive value. Another important character of leguminous plants is their ability to transfer nitrogen A TEXT-BOOK OF GRASSES 20 One dot represents Fic. 9. Production of grains cut green in the United States. 10,000 tons. Fic. 10, Production of coarse forage in the United States. One dot represents 20,000 tons. FORAGE PLANTS 21 from the air to the soil, thus increasing the soil fertility. This transfer is accomplished by means of organisms con- tained in nodules upon the roots of legumes, these organ- isms, which are allied to bacteria, being able to extract free nitrogen from the air. The accumulated nitrogen is in part passed on to the host plant. After the removal or death of the latter, the roots or such portions as remain in the earth return to the soil in a form available for absorption such nitrogen as was stored in them. For this reason the fertility of soils is increased by the growing of legumes, the following crops being correspondingly improved. The various grasses cultivated for forage are usually grown in combination with legumes either simulta- neously or successively, in order to increase the nutritive value of the product and at the same time to retain the fertility of the soil. 16. Miscellaneous.—The third group of forage plants includes all plants that do not belong to the grasses or the legumes. Certain plants of the mustard family, especially rape (see Farmers’ Bulletin No. 164), are cul- tivated for forage. Most of the plants of this group, with the exception of rape, are native range plants, deriving their importance from their presence in arid or semi- arid regions. The most important of those found in America are the salt bushes (species of Atriplex) (see Farmers’ Bulletin No. 108), winter fat (Hurotia lanata (Pursh) Mogq.) and the prickly pear cactuses (species of Opuntia). The cultivation of the opuntias has recently been undertaken in the southwestern states and gives much promise (see Farmers’ Bulletin No. 483). Species of Plantago, known to ranchmen as Indian wheat, are important winter grazing plants for sheep in the desert regions of Arizona and California. 22 A TEXT-BOOK OF GRASSES CLASSIFICATION OF FORAGE PLANTS ACCORDING TO USE 17. According to the way in which they are used, forage plants may be divided into three classes. These are: pasture plants, meadow plants, soiling and silage plants. PASTURE PLANTS 18. Pasture plants in the widest sense are those which furnish forage in situ, that is, those upon which stock graze. A pasture is an area supporting or containing pas- ture plants. In the restricted sense a pasture is a fenced area. In some localities the term is further restricted to areas of cultivated plants. Small pastures or areas of turf are sometimes known as paddocks. Pastures in the general sense may be divided into two classes, native pastures and cultivated pastures. Native pastures 19. Native pastures include all areas of native vegeta- tion upon which stock is grazed. Fenced pastures are common throughout the United States in connection with all farming operations that include the care of live-stock. Such pastures may include native prairie grass land, as is frequently the case in the region between the Mississippi River and the Rocky Mountains, or they may include areas that are wooded, that are rocky or sterile, that are too wet, or that are otherwisé not well suited to field crops. 20. Ranges.—Unfenced native pasture land is usually referred to, especially in the western half of the United States, as range, and animals feeding or grazing upon such eee aes eee FORAGE PLANTS 23 areas are said to be upon the range. During the last half of the last century vast areas in the West were utilized as range for stock, chiefly cattle and sheep. The usual practice in raising stock under range conditions is the ranch system. The ranch is the headquarters for the owner or manager of the farm and the stock. Here are the necessary buildings and other equipment. This central area is located near a stream or other water-supply, and more or less of the land in the vicinity is owned by the ranchman. The land lying beyond the limits of the ranch is open range, that is, unoccupied land, owned usually by the federal government, by the state, or by the bond- aided railroads. Such land at that time was of little value unless there was access to water. The result of these conditions was that the valley land along the streams was purchased for the use of the ranches, this ownership giving the use and virtual control of an indefi- nite area on the upland beyond. The cattle or sheep were herded on this range, the distance traveled being limited by the necessity of returning from time to time for water. Sheep are able to obtain water by eating snow, hence they can be herded during the winter upon desert regions lacking the ordinary water-supply, provided there is sufficient snowfall. It is therefore customary in the mountainous regions of the West to herd sheep in the mountains in the summer and take them out on the desert in the winter. Within recent years the demand for farm land has increased and the amount of open range has correspond- ingly decreased. Ranchmen in many cases have been obliged to buy and fence pasture land for their stock. Another modification of the original ranch system results from the policy adopted by the federal government in 24 A TEXT-BOOK OF GRASSES connection with the national forests. These reserves were formerly available as open range, but now stock is excluded except as permission is obtained for grazing by leasing. The terms of the lease provide for a maximum number of stock at a definite price a head to graze over a limited area for a limited season. In the open range system it was customary for the ranchmen to arrange among them- selves the use of the range. As they did not own or lease the open range they could not keep out rival ranchmen except by force. This not infrequently gave rise to strife, sometimes accompanied by bloodshed, between the opposing ranchmen or their herders, especially between the cattlemen and the sheepmen. The especial seriousness of the contests between the cattlemen and the sheepmen arose from the fact that cattle will not willingly graze after sheep probably because of some odor, whereas sheep will graze after cattle. Furthermore, sheep graze the forage much more closely than do cattle, so that after a band of sheep has passed over an area there is little or nothing left for the cattle. In former years ranchmen of the more southern regions carried their stock through the winter upon the range, depending upon the dry but nutritious grass remaining from the preceding season. Not infrequently there was loss of stock during stormy weather. In the northerly regions, and now, in accordance with the best practice also in the South, supplementary feed is supplied to stock during the winter months. 21. Overgrazing—Wild pasture land will permit of a certain amount of grazing without deterioration. Beyond this amount the grazing capacity becomes progressively reduced. This condition is caused partly by actual injury to the vegetation, partly by the reduction of its recupera- FORAGE PLANTS "25 tive power, and partly by the fact that grazing animals select the best plants, thus exterminating the valuable species, whose place is taken by the unpalatable or worth- less weeds. Range that has been grazed beyond its ability to recuperate is said to be overgrazed, and when the num- ber of stock on a given area is too great, the range is said to be overstocked. The amount of stock which the range will carry depends upon the kind and amount of vegeta- tion, the fertility of the soil, the rainfall, and various other conditions. The carrying capacity can be told only by experience. A range must be exceptionally good to average for a season one cow to every 5 acres, and such ranges would be found only in the less arid portion of the Great Plains where the grass is abundant. Overgrazing may be the result of necessity. The ranchman having in his possession a certain amount of stock may be confronted with an unfavorable season or a diminished range. As the free range decreases owing to the use of the land for general farming, or is bought up and fenced in by the ranchmen for self-protection, the tendency to overstock becomes greater. Too often under these conditions, the stockman is confronted with the necessity of providing feed for the stock he has, without regard to the ultimate welfare of the range. 22. Rejuvenating worn-out ranges.—As vast regions have been made temporarily unfit for grazing by the attempt to carry on the range for successive seasons more stock than it would bear, there has been an increasing pressure for methods that would quickly rejuvenate these areas. It has been thought that the seeds of grasses or other plants that are as well or better adapted to the conditions than was the preceding vegetation might be sown on the range to advantage. Many experiments have 26 A TEXT-BOOK OF GRASSES been tried along this line but with little success. The area involved is too large and the expense is too great. There is the further difficulty of finding plants better adapted. to the conditions than those that primarily occupied the soil. The plants that tend to come in to replace those sub- dued by grazing are usually weedy annuals that have little forage value. Such are the numerous species of Old World brome-grasses that are now so common on the Pacific slope and in some portions of the region to the east of this. There is one exception to this, the annual herbaceous plant known as alfilaria or ‘‘filaree’” (Hrodium cicutarium (L.) L’ Herit.) a member of the geranium family. This is an excellent forage plant and is gradually spreading on the ranges of the Southwest. The only practicable method to rejuvenate worn-out ranges is to give them rest. If stock is kept from them they will in time return to a condition of productiveness. The length of time necessary for an overgrazed range to recu- perate depends upon many conditions. If the overgrazing has been for a short period a single season of rest may be sufficient. If a considerable portion of the original vege- tation has been destroyed two or three seasons may be necessary. In the latter case the resulting vegetation will probably be different from the original and may be less valuable. Thoughtful ranchmen are learning to conserve their ranges by regulation and rotation and by limiting the stock to the carrying capacity of the range. (See Bur. Pl. Ind. Bulletin No. 117 and Yearbook for 1906.) Range grasses 23. The wild plants upon the range, unless they are positively distasteful because of bitter or acrid substances FORAGE PLANTS 27 or are protected by spines, are all more or less grazed by stock, especially sheep. If there is an abundance of forage the animals select the more palatable and nutritious spe- cies. In overstocked areas the animals are forced more and more to eat unpalatable or even poisonous species. On the prairies and plains of the western states, the grasses form the chief element of the forage. The most important single species probably is buffalo-grass (Par. 245). This is the dominant species on the Great Plains from the Dakotas to Texas and from the Rocky Mountains to the 100th meridian and beyond. This region is collo- quially known as the “short-grass country,”’ to distinguish it from the prairie regions to the east, where tall grasses prevail. On the plains of Texas and northern Mexico, the buffalo-grass is gradually replaced by a species of similar habit, the curly mesquite (Par. 212). The grama-grasses in numerous species in the West and Southwest and on the table-land of Mexico form an important and nutritive constituent of the ranges. The most important of these is the blue grama, called in the Southwest merely grama, and on the plains grama-grass, extending from Manitoba to South America. Like buf- falo-grass it is a “short grass’ and is frequently confused with that species. The three grasses, buffalo-grass, curly mesquite and grama-grass, form a nutritious forage after they have been cured in the autumn by the dry climate of this region. Hence the range will support stock through- out the winter if the conditions are favorable. Fall or winter rains, or an early frost, decrease the value of the forage. Other especially important western grasses are the various species of Agropyron, Andropogon and Muhlen- bergia. Pine-grass is important in Oregon and Washing- 28 A TEXT-BOOK OF GRASSES ton. The term “bunch-grass’”. is applied to diverse spe- cies in different regions. The name refers to any species that forms conspicuous tufts. In western Kansas it refers to Sporobolus airoides; in Oregon to Agropyron spicatum; in other localities to various other species. (See Yearbook for 1900.) CHAPTER IV CULTIVATED PASTURES EXPERIENCE has shown that, conditions being equal, a greater amount of forage can be grown from a given area if the plants used are cultivated. In the broad sense, the term cultivation is here used to include the sowing of seed or the setting out of plants. But cultivation in the usual sense means also that the soil has been prepared for the reception of the seeds or plants and may include still further the subsequent use of tillage implements. Culti- vated pastures, besides producing a greater amount of forage, have the further advantage of the choice of plants to be grown. Forage plants are cultivated for several purposes, as previously indicated, but in the present chapter only their cultivation for pasture is discussed. Cultivated pastures are usually known as tame pastures, to distinguish them from wild or native pastures. In regions where native pastures are rare, the term pasture may imply that the area has been seeded. Tame pastures are conveniently divided into two kinds, permanent and temporary. PERMANENT PASTURES 24. As permanent pastures are here included all pas- tures that are seeded down with the intention of using them for grazing for more than one season. The plants used for permanent pasture are primarily grasses. Legumes and other plants may be mixed with the grasses (29) 30 A TEXT-BOOK OF GRASSES or may be used temporarily or incidentally for grazing but (except sometimes alfalfa) are never used alone for permanent pasture. 25. The two most important pasture-grasses are blue- grass and Bermuda-grass. Other pasture-grasses of some importance are redtop, brome-grass, orchard-grass, mea- dow fescue. Still others are occasionally sown in mixtures but in the aggregate are almost negligible from the com- mercial standpoint. Some of these are the various fescue grasses, such as sheep’s fescue and red fescue, rye-grass, velvet-grass, and a few others. The most important legume used in permanent pasture mixtures is white clover. Blue-grass 26. Blue-grass is the standard pasture-grass in the region lying east of the Great Plains and north of Arkansas and North Carolina and extending southward in the mountains. It is used occasionally in other parts of the country, but it does not succeed in the southern states. It thrives best on limestone soils and is not adapted to acid soils. The famous ‘‘blue-grass region” of Kentucky lies in the limestone country in the central and northern part of the state. The species is commonly called Ken- tucky blue-grass and in some localities, especially north- ward, it is called June-grass. Blue-grass is an aggressive species and, in soil adapted to its growth, tends to spread. It thrives in partial shade, and, in regions where the summers are hot and dry, it invades the open woods, where it furnishes valuable pasture. An excellent way to utilize brush-land or open timber-land is to clear out the underbrush and weeds and sow the land to blue-grass. At first it is necessary to keep CULTIVATED PASTURES ol down the brush and weeds, but later the blue-grass dominates the undergrowth. In the alfalfa regions of the West, blue-grass is often looked upon as a weed, because of its tendency to invade alfalfa fields. The chief objections to blue-grass are the tendency to lie dormant during the hot dry midsummer, the diffi- culty in establishing a stand, and the low forage yield. _In spite of these objections, it leads all other pasture- grasses in the region where it thrives. 27. Establishing a blue-grass pasture—Blue-grass is rather difficult to start, as the growth is slow the first year. About sixty pounds of seed an acre are sown. It is important to have good seed. Many of the failures to establish a good stand are due to sowing seed of low vital- ity. If the seed is good, thirty pounds to the acre should be sufficient. The seed is sown on prepared land, or with other crops such as clover, wheat or timothy, or with meadow grasses or in early spring upon the snow or upon frozen ground. The object of sowing with other crops is to utilize the land while the blue-grass is becoming estab- lished. In regions adapted to its growth, blue-grass will form a permanent pasture, since few plants can drive it out unless it is overgrazed. Bermuda-grass 28. Bermuda is the standard pasture-grass for the South, occupying there the position of relative importance among grasses that blue-grass does in the North. Its dis- tribution is from the blue-grass area to the Gulf of Mexico and west to east Texas. Bermuda-grass is common in the warmer parts of both hemispheres and in the United States extends into the arid regions of the West. In the 32 A TEXT-BOOK OF GRASSES latter regions it is of little importance from a commercial standpoint, since the climate is too dry for its develop- ment without irrigation. Under irrigation, other forage crops give better results. Although Bermuda-grass is found under a variety of conditions, it is not a shade- loving plant and thrives best in open ground. On the uplands of the South it leads all other pasture grasses but in the moist lowland along streams and along the coast it has a few competitors, especially carpet-grass (Par. 215) and St. Augustine-grass (Par. 223). It withstands heat and drought, is aggressive, forming a permanent pasture, and is nutritious. Sometimes legumes (espe- cially bur clover (Medicago arabica) and Japan clover (Lespedeza striata) are combined with Bermuda. 29. Establishing a Bermuda pasture——There are two methods of starting Bermuda: by sowing the seed and by planting cuttings. The seed is sown at the rate of six to eight pounds to the acre and pressed in with a roller. The more usual method is to plant cuttings of the stem or pieces of the sod. These are dropped at intervals in shallow furrows and covered with a plow or dropped upon a pre- pared surface and pressed in with the foot. Bermuda-grass is very aggressive, for which reason it becomes a bad weed when it invades cultivated fields. In cultivated soil it produces hard, vigorous rootstocks that give it the name of wire-grass. It can be eradicated by plowing in the hot weather of midsummer, or by smothering out by means of rank-growing shade crops, such as cowpeas. Bermuda-grass does not usually pro- duce seed in the United States except in Florida, Arizona and California; hence it invades fields slowly and with care can be kept out without much difficulty. The com- mercial seed is imported. CULTIVATED PASTURES 33 Other pasture-grasses 30. Besides the two important and well-known pasture- grasses mentioned for the North and the South, there are several others that are used to a considerable extent. Each has its special merits and its peculiar drawbacks. The acreage of some of these grasses is large but in all cases falls far below that of blue-grass and Bermuda- grass. 31. Brome-grass.—This is variously known as awnless brome, Hungarian-brome, and Bromus inermis, the last being its botanical name. It is one of the few grasses that has been successfully introduced into cultivation in recent times. The United States Department of Agricul- ture and the state experiment stations have demonstrated its adaptability to the conditions prevailing in the north- western states. It has been shown to be an excellent pasture-grass for the region from Kansas to Manitoba and west to Washington, which is too dry for the eastern grasses. It gives good results east of this region, but must there compete with timothy, clover and_ blue-grass. Brome-grass is a native of Europe. (See Bur. Pl. Ind. Bulletin No. 111.) 32. Redtop.—This is a well-known widely distributed meadow-grass which will be further discussed under meadow-grasses. (Par. 48.) Its chief importance as a pasture-grass is due to the fact that it thrives on acid soil where blue-grass fails. It is a good pasture-grass for moist localities in the timothy region and especially in the coastal region from Virginia to New England. Redtop is called “‘herd’s-grass’’ in Pennsylvania and in some other localities. 33. Orchard-grass.—This is an excellent species for C 34 A TEXT-BOOK OF GRASSES the blue-grass region, especially when combined with other grasses. Its chief faults are that it grows in tus- socks and that the seed is expensive. The former draw- back militates chiefly against its use as a meadow-grass as the hummocks interfere with mowing. It withstands drought somewhat better than does timothy or blue-grass, hence is useful along the western edge of the timothy region. In eastern Kansas, it is used as a pasture-grass in combination with meadow fescues. (See Bur. Pl. Ind. Bulletin No. 100.) 34. Meadow fescue.—This is a common European forage-grass which has many excellent qualities but has not been extensively grown in the United States. It does not compete with timothy and blue-grass chiefly because the seed is more expensive and less reliable, faults it shares with several other good grasses. It is adapted to the same region as timothy and blue-grass. A taller form or agricultural variety with more open panicle is grown under the name of tall fescue. The seed of meadow fescue produced in the United States is nearly all grown in east- ern Kansas. Meadow fescue is sometimes incorrectly called English blue-grass. (See Farmers’ Bulletin No. 361.) 35. Rye-grasses.—Of these there are two kinds, the English rye-grass and Italian rye-grass. These are both standard forage-grasses of Europe but are infrequent in cultivation in this country. They are excellent grasses and deserve a wider use. The poor quality and high cost of the seed, together with the traditional importance attached to timothy and blue-grass, probably account for their restricted use. Canada blue-grass—This grass will not compete with Kentucky blue-grass on limestone soils, but in portions es CULTIVATED PASTURES 30 of the humid region where the latter does not thrive it serves a useful purpose. Nearly all the American seed is grown in the province of Ontario, Canada. (See Farmers’ Bulletin No. 402.) Tall meadow oat-grass—This is a good grass with poor seed habits, the seed shattering out badly in harvesting and handling. The species is adapted to the timothy region but is only sparingly grown. Velvet-grass——This species is of little value except on sterile soil where other grasses will not grow. It is well established on the Pacific coast, especially from northern California to British Columbia, where it is common in swamps, grass-land, waste places and open ground gen- erally. It is not much utilized for forage except on the sandy land around the Columbia River. Animals do not relish the hay unless they have acquired a taste for it. 36. Southern pasture-grasses.—In the moist regions along the Gulf coast, carpet-grass is a valuable and nutritious grass. This is a native of the tropics extending into the southern United States. It thrives in open, moist land where it forms a green carpet. It is not cultivated, but comes into natural pastures voluntarily and persists because it withstands grazing and trampling. Another species found especially in mucky soil along the Atlantic coast from South Carolina to southern Florida is St. Augustine-grass. This is similar in its habits to carpet- grass. (See Farmers’ Bulletin No. 509.) 37. Two common tropical grasses, Pard-grass and Guinea-grass, should be mentioned although except in the extreme southern portion they are not hardy in the United States. Pard-grass, a native of Brazil and cul- tivated in the lowlands throughout tropical America, is occasionally used for pasture in southern Florida and 36 A TEXT-BOOK OF GRASSES southern Texas. It is useful in wet or almost swampy land, where it will furnish a large quantity of forage. Pard-grass does not well withstand grazing because its extensive stolons, being above ground, are killed or injured by trampling. Guinea-grass grows on drier land than that best suited to Pard-grass. It is extensively used for pasture, hay and green fodder at low altitudes in the tropics. It withstands grazing well and its numer- ous basal shoots furnish a large amount of palatable forage. TEMPORARY PASTURE 38. Temporary pasture, as here understood, refers to pasture obtained incidentally from plants grown for other purposes, or to that obtained from annual plants. The usual kind of temporary pasture is that from plants grown primarily for hay. It is a common practice to graze meadows after the hay has been cut. Care must be taken that the meadow is not grazed too closely and the plants are not injured by the trampling of animals in wet weather. Alfalfa is commonly grazed in the West, where this may be the chief forage crop grown. There is objection to allowing cattle and sheep to graze on alfalfa and clover since these legumes are likely to cause bloat- ing. Fall-sown grain is often used for pasture, and stand- ing corn-stalks furnish considerable fodder after the corn has been removed by husking in the field. Annual plants for pasture 39. Grains, especially rye, are sometimes grown primarily for pasture, being sown usually in the summer or fall. Sorghum in some of its varieties is grown for pasture CULTIVATED PASTURES 37 in the South and Middle West. Rescue-grass is used in some parts of the South for winter pasture. Rye-grass can also be used to advantage for winter pasture in the South as it grows rapidly and produces feed sooner than perennial pasture-grasses. Rape and sometimes other cruciferous plants such as turnips and kale are sown for pastures. Various legumes may be used for this purpose, often in connection with their use as green manure or as a cover-crop. CHAPTER V MEADOW PLANTS MEADOW PLANTS are those used for hay. A meadow is an area upon which are growing plants that are to be cut for hay. Meadows may be conveniently divided into two classes, wild or native meadows, and tame or cultivated meadows. The hay product of the United States is one of the most valuable of the agricultural crops, the total yield of hay and forage according to the thirteenth census being 97,453,735 tons, valued at $824,004,877. NATIVE MEADOWS 40. There are three kinds of native meadows, accord- ing to the grass that grows upon them. These are prairie, fresh marsh, and salt marsh. In all cases the chief portion of the forage is made up of various species of grasses, the other plants being incidental or even harmful. Prairie hay is cut from native prairie that is sufficiently dry to be used for field crops. Because available for cultiva- tion, the area of prairie meadow is decreasing as the land is gradually broken by the plow. Open grass-land, such as swales, or the low areas along streams or ponds that are intermediate between arable land and swamps, is often reserved permanently for meadow. In the prairie region and in the eastern portion of the Great Plains, the chief constituents of prairie hay are (38) MEADOW PLANTS 39 bluestem (Andropogon furcatus), little bluestem (Andro- pogon scoparius), switch-grass (Panicum virgatum), Indian reed (Sorghastrum nutans), purple-top (Tridens flavus), tall grama (Bouteloua curtipendula), and wild rye (Elymus virginicus, and E. canadensis). In the swales or “sloughs,” as they are called in that region, the chief grass is cord-grass or slough-grass (Spartina Michauxiana). An important hay-grass in depressions or valleys on the plains is Colorado bluestem (Agropyron Smithiz). Throughout the mountain regions of the West the native hay may consist of a great variety of indigenous grasses, the species of Poa, Calamagrostis, Agropyron, and E£ly- mus glaucus usually predominating. On the western ranches where irrigation water is available, it is customary to flood the meadow land in the valleys. If too much water is applied, or if it is allowed to stand on the meadow for too long a time, the valuable grasses are gradually replaced by less nutritious plants, especially by wire-grass, which is a kind of rush (Juncus balticus Willd.). 41. The commercial production of wild hay is chiefly in the area from Oklahoma to Manitoba, including the eastern portion of the Great Plains and extending east- ward through Minnesota into Wisconsin. In the northern portion of this area, a large proportion of the wild hay is cut from marsh land, the most important constituents being bluejoint (Calamagrostis canadensis) and reed canary- grass (Phalaris arundinacea). Much of this hay land is too wet for cultivation. At the time of harvest the soil is sufficiently dry to support the mower and horses. In the marshes of Wisconsin and Minnesota the soil is so moist that broad shoes are sometimes attached to the horses’ feet to prevent them from sinking into the soft ground. 40 A TEXT-BOOK OF GRASSES 42. Salt marsh-grass is utilized for hay in many locali- ties along the seacoast. Large areas of marsh land sub- ject to the diurnal tides or to occasional high tides are useful for no other purpose than the grass crop that they produce. When utilized for hay these marshes are drained by open ditches. In some cases the sea is kept out by dikes, in which case the land becomes productive and valuable. The hay from salt marshes is of considerable value for fodder, the value depending on the kind of grass and the degree of salinity of the soil. Much of this hay is used for litter for stock and for packing-material. The chief constitutents of salt marsh-hay are switch-grass (Panicum virgatum), little bluestem (Andropogon scopa- rius), black-grass, a kind of rush (Juncus Gerardii Loisel.), all of value for forage, and several species of Spartina, or cord-grass (Spartina glabra and S. juncea being the most important), these latter being used chiefly for packing. TAME MEADOWS 43. Tame meadows may be divided into two classes, permanent and temporary. It is only to the former class that the term meadow is popularly applied. Permanent meadows 44. Permanent meadows are those that have been seeded down with forage plants with the intention of maintaining them for a series of years to produce hay. The chief meadow plants used in the United States are: of the legumes, alfalfa, red clover and to a limited extent alsike clover; among the grasses, timothy and redtop. MEADOW PLANTS 41 45. Alfalfa (Medicago sativa L.) is the most important forage crop in the United States. In the irrigated regions of the West it is almost the only forage plant grown and is there used for both hay and pasture. Alfalfa was intro- duced from Europe by the Spaniards and attained importance in our western states simultaneously with irrigation. Its use spread eastward in the arid and semi- arid regions until it reached the borders of the timothy region. Within recent years this crop has been success- fully introduced in many parts of the East and South. It does not thrive on an acid soil, hence the necessity of using lime in many parts of the East in preparing the land for alfalfa. Where a good stand is obtained, a permanent meadow is formed, yielding cuttings every four to six weeks during the growing season, two or three cuttings in the more northern regions, as many as ten in the hot southern valleys of California. The meadow lasts indefi- nitely, but sooner or later suffers from the incursions of various weeds and must be broken up and reseeded. As alfalfa is not a grass, it will not be further discussed here, but the student is referred for detailed information to Farmers’ Bulletin No. 339 from the United States Depart- ment of Agriculture. 46. The clovers are legumes belonging to the genus Trifolium. Certain allied plants are also known as clover but with a modifying term, such as bur clover (Medicago arabica Huds.), sweet clover (Melilotus alba Desv.), Japan clover (Lespedeza striata (Thunb.) Hook. & Arn.), all belonging to the family Leguminosz. The true clovers include the common red clover (Trifolium pratense L.), which is usually referred to merely as clover, alsike (7. hybridum L.), white clover (7. repens L.), and crimson clover (7. incarnatum L.). The first two are used for 42 A TEXT-BOOK OF GRASSES meadow, the third for pastures and lawns, the fourth as a cover, soiling and green manure crop as well as for hay. The most important of the clovers and one of our most important forage plants is red clover. This thrives in the humid region (Par. 110) and is often sown with timothy. Its chief use is for hay but it is also used as a cover-crop and for green manure. In common with alfalfa and other legumes, or even with rape, there is danger of causing bloating in cattle and sheep pastured upon clover. Alsike is better adapted than is red clover to wet soil and hence is utilized in meadows too wet for the latter and is usually sown with redtop. Alsike is of some impor- tance as a forage plant but the amount used in comparison with red clover is insignificant. (See Farmers’ Bulletins No. 455 on red clover, No. 550 on crimson clover, No. 485 on sweet clover, No. 441 on Japan clover.) 47. Timothy is the great meadow-grass of the north- eastern states which produces the standard hay of the market. Timothy is not so nutritious as some other grasses, yet it is the leading meadow-grass because it combines as does no other grass the requisite qualities. It is palatable, fairly nutritious, easily grown, and the the seed is cheap and of good quality. The cheapness of the seed is much influenced by the good seed habits of the plant. It produces seed abundantly and the heads grow to about the same height, ripen about the same time, and do not wastefully shatter the seed. Timothy is grown alone or with clover, and in either case may be sown with the addition of a nurse-crop of grain. It may be sown with wheat in the fall, the clover being added in the spring, or with clover in the fall, no nurse-crop being used. The addition of the nurse-crop is an attempt to gain time while the timothy and clover MEADOW PLANTS 43 are getting started. The term nurse-crop is applied to any quick-growing crop that supposedly protects another crop while it is young. Wheat sown in the fall produces a crop the following summer, and the timothy and clover have a better start than if sown after the wheat is cut. However, in most cases if the timothy and clover are sown together in the fall on well-prepared land, no time is lost, for a full hay crop will be produced the following year. If well seeded down timothy will produce crops for several years, but experience has shown that the best results are obtained by making the meadow a part of a rotation. On good, arable land, with suitable application of fertilizer, a timothy and clover meadow will yield heavy crops the first and second crop-year. After this the amount of the crop decreases. Hence it is more profitable to plow up and plant to another crop such as corn, some- times with an intervening year devoted to pasture. 48. Redtop.——On lands where timothy is at its best, there is no competing meadow-grass; but, on soil too moist for the best results with timothy, which is often also acid soil, redtop is the most satisfactory meadow- grass. The region where redtop is most extensively grown is the Atlantic slope from New England to Maryland, although it is also grown to a limited extent throughout the timothy region. It can also be grown to advantage somewhat farther south than can timothy. 49. Johnson-grass is an excellent meadow-grass for the states from Georgia to Texas. It yields large crops of nutritious and palatable hay and can be grown easily and cheaply. On the other hand it is a very aggressive species, propagating readily by seed and by strong under- ground creeping stems or rootstocks. When once in pos- session of a field it is difficult to eradicate. For this reason, 44 A TEXT-BOOK OF GRASSES in spite of its good qualities, it is looked upon as a per- nicious weed. It is not wise to introduce this species on land that is free from it. A meadow should be a part of a rotation, and Johnson-grass does not readily give up its place to the following crop. When a permanent meadow is desired, this grass, if its weedy habit be not taken into consideration, is probably the best for the purpose in those parts of the South, such as the black soil of central Texas, where it reaches its highest development. It is less satisfactory as a pasture-grass since, not well with- standing grazing, the yield decreases after two or three years. If a farm is already infested with Johnson-grass it is well to take advantage of its useful qualities as a meadow-grass. As this species tends to become sod-bound in a few years owing to the rapid multiplication of root- stocks, the field should be plowed every two or three years. 50. Eradication of Johnson-grass—Johnson-grass can be eradicated, but the process requires more care than in the case of most weeds. Plowing in the fall with a turn- ing plow, harrowing out and removing the rootstocks, sowing the field to early-maturing grain, oats or rye, cut for hay in the spring, and following with a cultivated crop, will keep the grass in subjection. In the region where Johnson-grass reaches its greatest development, alfalfa also thrives. Hence an excellent method to utilize an infested field is to sow alfalfa. This is done in the fall after the field has been plowed and harrowed to remove the rootstocks. The alfalfa soon smothers out most of the Johnson-grass, and the hay is not injured by the pres- ence of such of the latter as may remain. Johnson-grass shares with sorghum the tendency to poison stock through the production, under certain conditions, of hydrocyanic acid. (See Farmers’ Bulletin No. 279.) MEADOW PLANTS 45 51. Other meadow-grasses.—Various grasses other than the three mentioned are recommended for meadow mixtures but none is used to any considerable extent. Orchard-grass is a desirable grass, yielding a good crop of nutritious hay. The chief objection to it is that it grows in heavy tussocks that make an uneven bed for a mowing machine. Furthermore the seed is rather expensive. The cost of the seed also militates against meadow fescue, another good meadow-grass. The prestige of timothy is probably one of the reasons why some of the less known grasses are not used to a greater extent. Tall meadow oat-grass and the two rye-grasses, English and Italian, are often recommended for mixtures. Velvet-grass is of little value except on sandy land where better grasses will not thrive. Other grasses mentioned in seed catalogues and occasionally used in mixtures are rough-stalked meadow-grass, fowl meadow-grass, crested dog’s-tail, sweet vernal-grass, and meadow foxtail. It should be added that the two important pasture- grasses, blue-grass and Bermuda, are sometimes used for hay in the regions where they reach their maximum development. Guinea-grass is occasionally used for hay in the tropics, for which purpose, because of its numerous leafy basal shoots, it is well adapted; but farm practice in the warm regions usually calls for a soiling crop rather than a hay crop. 52. Slender wheat-grass.——The only native meadow- grass whose seed has become a commercial product is slender wheat-grass (Agropyron tenerum). It is a native bunch-grass of the western states and is adapted to the semi-arid region of the Northwest, where it should form a permanent meadow or pasture. It has not been sufficiently tested as yet to determine its comparative value. 46 A TEXT-BOOK OF GRASSES Temporary meadows 53. Under temporary meadows are included annual crops sown or planted for hay, although fields of such crops are not often popularly designated’ as meadows. The plants most used for this purpose are: the grains, foxtail millet, sorghum, corn and certain legumes, such as cowpea and field pea. Several other plants are used locally or sporadically. 54. Grain hay.—Probably the most important group of annual plants used for the production of annual meadows is that of the grains. From the commercial standpoint grain hay is of importance only in the western states and particularly on the Pacific coast. In this por- tion of the United States, except in the mountain meadows, there is little native vegetation suitable for hay. Under irrigation, alfalfa is the standard forage crop; but, over a large area where the rainfall, though small, comes chiefly during the winter, it is possible to grow crops of grain without irrigation. The grains used for hay in the Pacific coast states are mostly wheat and oats. In some locali- ties barley, especially beardless barley, is used. Another important constituent of the grain hay is wild oats (Avena fatua, A. fatua glabrata, and A. barbata). This is widely distributed, and an abundant volunteer crop may appear in a field after a grain crop is harvested. In Washington and Oregon chess or cheat is sometimes cultivated for hay. 55. The relative importance of grain hay may be estimated from the data for California taken from the report of the thirteenth census and given in the following table. Important as is the alfalfa crop, its value is exceeded by that of grain hay. MEADOW PLANTS 47 TABLE XVI ACREAGE, PRODUCTION AND VALUE OF GRAIN Hay IN CALIFORNIA COMPARED WITH THE TOTAL Hay AND FORAGE AND WITH ALFALFA Crop Acres Amount (tons) Value a ee eee ee | Hay and forage .... 2,533,347 4,327,130 | $42,187,215 a) 484,134 1,639,707 | 13,088,530 2 1,604,745 2,019,526 | 24,056,727 In the eastern states, grain hay, especially oats, is used on the farm in the sheaf, but nowhere does it reach any considerable commercial importance. Straw, as a by-product of grain-growing, is of some importance. Its use as forage is of secondary rank and is mostly confined to the farm, the mature straw having little nutritive value. When it enters commercial channels it is mostly for bedding and packing, though specially prepared straw may have other uses such as the making of hats. MILLETS 56. By millet is meant foxtail millet as distinguished from several other grasses called millet, but with a modify- ing term, such as proso millet (Par. 217), pearl millet (Par. 221), Japanese barnyard millet (Par. 218) and African millet (Par. 210). Millet as grown in the United States is found in two forms, common millet and Hungarian-grass (Par. 220). A form of common millet was much adver- tised a few years ago as Golden Wonder millet. The variety known as German millet is also a form of the common millet, differing chiefly in its longer season of growth. Millet is grown in the eastern half of the United States, especially in the region from Oklahoma to Iowa. It produces an abundance of nutritive and palatable hay 48 A TEXT-BOOK OF GRASSES relished by all kinds of stock and in general is a valuable forage plant. Horses sometimes appear to suffer injury if fed millet exclusively but cattle and sheep are free from this danger. If cut too late the bristles of the seed-heads may become troublesome. It can be sown after a grain crop or in place of other crops when there has been a failure to secure a stand. The tenderness of the growing plants render early sowing impracticable. (See Farmers’ Bulletin No. 101.) 57. Sorghum is grown in many parts of the world and, according to the variety, for many different purposes. The seed is used for food for man in parts of the Old World, and.in the United States that of certain forms, such as kafir, is used for stock feed. One variety is called broom- corn (Par. 211). The saccharine sorghums or sorgo con- tain much sugar in the sap and are used for the commer- cial production of sugar (Par. 97). The saccharine varie- ties such as the Orange and Amber, and also some of the non-saccharine such as kafir and milo, are grown for forage. Those which are grown for the seed may furnish forage also, the stalks being cut and shocked as in corn, the grain being thrashed out or the heads cut off and the remainder used as rough forage. In the semi-arid region where drought-resistant hay crops are needed, sorghum is much used as a hay crop. For this purpose it is sown or drilled thickly, so as to produce numerous slender stems, and the crop mowed and cured as hay. In some parts of the Middle West, sorghum is known as “cane.” (See Farmers’ Bulletins Nos. 246, 288, 322, 448, 552.) 58. Corn or maize is sometimes sown thickly and used for hay as is described above for sorghum. The most common use of corn as forage is in connection with its use as a grain crop. The corn may then be treated in MEADOW PLANTS 49 two general ways. It may be allowed to mature in the field, the grain being taken away, allowing the standing stalks to remain. This is known as husking the corn from the row or from the field. The stalks are then pastured during the winter, the animals feeding upon the dead leaves and upon any ears that may have been overlooked by the husker. Mature cornstalks, however, have little nutritive value. The other way is to cut the cornstalks and shock them in the field, before the ears are mature and while the leaves are yet green. The shocks remain until the forage is cured and the ears have matured. The ears may be husked in the field and the forage stored in stacks or sheds or the shocks may be hauled to the barns where the husking is done either by hand or by machinery. The forage or corn-fodder produced in this way is much more nutritious than that which is matured before husk- ing, and the grain suffers little loss by the process. Corn and kafir are sometimes cut and bound in bundles by machinery, a process which lessens the labor of shocking. 59. Other grasses producing hay or coarse fodder.— Several other grasses are used locally for the production of coarse hay. Some of these have undoubted merit but usually must compete with the more important species mentioned previously. Others are native or weedy species that are utilized locally. A more complete account of some of these grasses is given in Part II. 60. Japanese barnyard millet—Several varieties are grown in Asia and have been tried in America, but with little success. One variety has been advertised under the name of billion-dollar grass. They require plenty of water to produce crops, and in the humid regions will not com- pete with other grasses. They have some value under irrigation in the Southwest. D 50 A TEXT-BOOK OF GRASSES 61. Proso millet—This is the common millet of Europe, where it is grown extensively for forage and for the seed, the latter being used for food for animals and also among the poorer classes for man. In this country it has been tried repeatedly, but the results have not been very satisfactory. It does not compete with other plants for forage, but produces under favorable condi- tions an abundance of seed. This may prove valuable for poultry. The seed can be used also for stock, but shatters rather readily. Proso millet is also called broom-corn millet because of the resemblance of the inflorescence to that of broom-corn. Another name is hog millet. 62. Pearl millet and teosinte are sometimes used for hay, but usually for soiling (Par. 75). Texas millet is a native weedy species found in the valley of the Colorado River and neighboring valleys in southeast Texas. The volunteer crop on rich land is cut for hay, this being of good quality. Texas millet is also known as Colorado-grass. Crab-grass may be mentioned here, as it is frequently cut for hay in the South, where it appears in fields as a weed. The hay is of good quality, but is mostly used on the farm and does not often appear on the market. Chess or cheat (Bromus secalinus) is grown for hay locally in Oregon, especially in the Willamette Valley. This in other regions is a weed in grain fields but there has been utilized successfully. 63. Several annual legumes are used for the produc- tion of hay or coarse forage. They are usually used as a cover-crop or as green manure in connection with other farm processes. They are used extensively, especially in the South, as a part of a rotation in order to maintain the fertility of the soil. As stated previously (Par. 15), MEADOW PLANTS 51 the legumes have the power to add nitrogen to the soil by means of the root nodules and the nitrogen-fixing organisms contained therein. The choice of the legume for this purpose depends largely upon the secondary uses that can be made of the crop. It may be made into hay or may be cut green and used for soiling or for silage (Par. 76). In the timothy region, clover is a staple crop (Par. 46). In the South, where no perennial legume is adapted to the conditions prevailing over most of the region, annual legumes are used. It is true that alfalfa is grown with success in many parts of the South, such as _ the alluvial valleys of the Mississippi and Red Rivers, and the black soil of central Alabama, but even here an annual crop may be desired for the other purposes mentioned above. The commonest of the annual legumes in the South are the cowpea and velvet bean. In the North, the field pea is much used, and in middle regions vetch and crimson clover. 64. The cowpea (Vigna sinensis (Torner) Savi.) is a trailing vine with trifoliate leaves and slender, bean-like pods. Some varieties are bushy and trail only slightly. The cowpea is the standard legume for the South. Its use has extended gradually northward until some varieties are now grown as far as Michigan. It is a warm-weather species and cannot be sown until the season is well advanced. In the South this limitation presents little difficulty, but in the North only quick-growing and more hardy varieties can be used. The hay from cowpea is excellent in quality, but, like all succulent forage, requires special care in harvesting and curing. It should be remembered that the feeding value of a legume like the cowpea is much greater than its fertilizing value. Hence the dual use of the crop, the greater part of the vines 52 A TEXT-BOOK OF GRASSES and leaves being used for hay or green feed, the remainder being turned under for green manure. When grown on sterile soil it may be necessary to turn under a larger proportion in order to produce humus. (See Farmers’ Bulletin No. 318.) 65. Velvet bean (Stizolobium Deeringianum Bort).— This coarse rank-growing vine is similar to the cowpea but gives a much greater growth. The velvet bean is not so hardy as the cowpea and is used only in the South. It has given excellent results in Florida. (See Farmers’ Bulletin No. 509, and Bur. Pl. Ind. Bulletin No. 179). 66. The vetches are upright or reclining plants with tendrils at the ends of the compound leaves. In a general way they resemble the garden pea, but the leaflets and flowers are smaller. There are two common kinds of vetch in use in the United States—spring vetch (Vicia sativa L.) and hairy vetch (V. villosa Roth). The one most grown is the latter, since it better withstands drought. The vetches are usually sown with grain, the latter supporting the vetch, thus producing a combina- tion that can be harvested with greater ease than can the vetch alone. Vetch may be used as a winter crop in the South or as a summer crop in the North. (See Farmers’ Bulletins Nos. 515, 529.) 67. Crimson clover (Trifolium incarnatum L.)—This is a tall clover with long heads of crimson flowers. It is rather extensively used in the region from New Jersey to North Carolina. It should be cut when in flower. If cut later the fuzzy hairs around the head prove troublesome, especially to horses. (See Farmers’ Bulletin No. 579.) Field pea (Pisum arvense L.). The field pea, resembling the garden pea in habit, is much used in Canada and our more northern states. The field pea requires a cool, MEADOW PLANTS 53 moist climate, hence is not adapted to the regions farther south. It is usually sown with grain for the reasons men- tioned under vetches. (See Farmers’ Bulletin No. 224.) The soybean (Soja Soja (L.) Karst., Glycine hispida Maxim.) is an upright plant that tends to become bushy. In southeastern Asia, where the species is native, it is extensively cultivated, the seed being used for human food. In the United States the soybean is grown for both seed and forage. The seed, rich in protein, is used for feeding stock, usually in the form of soybean meal. As a forage plant, it can be utilized for hay or for pasture. The soybean is adapted to the cotton-belt and north- ward into the southern part of the corn-belt. Being much more drought-resistant than the cowpea it can be grown in the southern part of the Great Plains. (See Farmers’ Bulletin No. 372.) Sweet clover (Melilotus alba) is a vigorous grower and makes excellent hay, the chief objection being that stock do not readily eat it until they have acquired a taste for it. The plant is a biennial, producing the flowers the second season. The hay should be cut before seed is formed. Sweet clover is also known as Bokhara clover. (See Farmers’ Bulletin No. 485.) Florida beggar-weed (Meibomia tortuosa (Swartz) Kuntze). This has been used with success in Florida and the Gulf states. It is a tall plant with trifoliate leaves and flat, constricted pods that break up into one-seeded joints that adhere to wool or clothing by means of a covering of hook-like hairs. (See Farmers’ Bulletin No. 509.) CHAPTER VI HAY AND GREEN FEED THE product of meadows may be fed immediately or it may be preserved. If it is fed immediately, the process is known as soiling, and crops grown for this purpose are called soiling crops. To preserve forage it must be pro- tected from decomposition or rotting. This may be accomplished by removing a sufficient proportion of water by drying, in which case the product is called hay. Or the forage may be preserved green, the destructive decom- position being prevented by the exclusion of the air. The preserved product is then called silage. HAY 68. In the wide sense, hay is dried vegetation used as food for animals. In this sense ripened buffalo-grass and standing cornstalks, grazed during winter, are hay. In the restricted sense, the word hay is applied to the cut and dried or cured product of meadows, more particularly the product of the smaller grasses and clovers. The coarse hay of cornstalks and other large grasses is more often called fodder. Ordinarily meadow hay is made by cutting with a mower and allowing the cut material to lie in the sun until partly dried, after which it is raked into wind- rows, then placed in bunches or cocks and finally in stacks or under a roof. The process is varied to suit con- ditions. The object is to remove sufficient moisture to (54) HAY AND GREEN FEED 55 prevent molding when stored. In dry, sunny weather little difficulty is experienced in producing good hay; but, in humid climates, hay-making is a process requiring much care. Rain and dew delay the drying and reduce the quality of the hay, or they may render the product entirely worthless. It is readily seen that weather conditions become an important factor in hay-making. Putting hay in cocks and covering with some kind of impervious shield is an attempt to prevent the absorption of water. 69. In arid regions the hay may be cut and stacked the same day, but in humid regions the curing may extend over several days with the corresponding risk from rain. Succulent plants, such as clover, alfalfa and cowpea, demand especial care because the stems require a longer time than the leaves for curing. The foliage drops off readily and is lost when there is much delay in curing. As the leaves are the most important part, this loss becomes serious. The vines of cowpea and velvet bean are so succulent that special methods of curing are fre- quently adopted. It is a common practice in the South to cure the vines on upright racks or poles so as to allow a circulation of air. A single pole with the vines arranged around it, makes a tall, slender bunch or cock that gives much lateral surface in proportion to the area of the top. 70. Stacks.—Hay that is stacked in the open deterio- rates on the exposed portion and there is a considerable percentage of loss from the weathering of the outer por- tion of the stack. Careful building of the stack and a covering of reeds or canvas reduces the loss. Hay stored in barns suffers practically no loss, and in sheds only in proportion to the exposed surface. On the large ranches of the West it is impracticable to store in barns the large 56 A TEXT-BOOK OF GRASSES quantity of hay produced, and the climatic conditions render this unnecessary. 71. Hay in the West——When hay is made on a large scale such as prevails on many western ranches, the pro- cess involves the use of several appliances not often seen on the smaller farms of the East. The mower and horse- rake are common everywhere. To transport the bunches of grass hay to the stack a sweep or bull rake is often used. This is an implement with large teeth, that slides along the ground and under the bunches. For alfalfa it is better to load on wagons as the sweep tends to shatter the foliage. The sweep can not be used for long distances. At the stack the hay is transferred from the wagons or from the sweeps by large forks worked by horse-power. These forks are operated in connection with some form of pole derrick, or less frequently with a cable derrick. Nets or slings are often used to unload wagons. These are placed at intervals in the load, which can then be hoisted off in three or four parts with a derrick. 72. The standard hay on city markets in the East is timothy and all other kinds are estimated in comparison with timothy. The demand here is for hay suitable for horses, and custom has come to consider timothy as best satisfying this demand. Clover mixed with timothy may increase the feeding value but may also reduce the mar- ket value in these markets. The demand for timothy in preference to other hay is largely due to the wishes of the livery stables, timothy being considered by horsemen to be the best hay for livery horses. In localities in which prairie hay enters the mae it is demanded in preference to alfalfa for livery horses. 73. Baled hay.—In recent years the baling of hay has become an important industry and baled hay has almost HAY AND GREEN FEED 57 replaced bulk hay upon the market. Of course all hay that enters commercial channels is baled, bulk hay being confined to the local market. Even for use upon the farm or ranch the hay may be baled for convenience in hauling and storing. As baled hay occupies only 140 to 160 cubic feet to the ton there is a great saving of space over hay sold in bulk. The standard bale weighs 70 to 250 pounds; the small bale, much used in the South, 70 to 100 pounds; the medium bale, 100 to 150 pounds, and the large bale, requiring two men to handle, 150 to 250 pounds. Any kind of hay, straw, or fodder may be baled, but the baled hay in commerce in the United States consists mostly of timothy, prairie hay, alfalfa, and grain hay, the latter largely confined to the Pacific coast. The classes of hay recognized in the East by the National Hay Associa- tion are timothy, clover-mixed (timothy and clover), clover, and prairie, with two to five grades each. For transportation to trans-oceanic points, especially Alaska and the Philippines, the hay may be double compressed. For this purpose hay obtained by loosening ordinary bales is compressed by powerful hydraulic or electric presses similar to those used for compressing the cylindri- cal bales of cotton. The resulting bale is very compact, the square form occupying 85 cubic feet to the ton, and the cylindrical bales only 55 cubic feet. (See Farmers’ Bulletin No. 508.) SOILING AND SILAGE CROPS 74. Soiling is the system of feeding to animals in in- closures green forage recently cut from the growing plants. Silage is the system of preserving fresh green forage in suitable more or less air-tight receptacles. 58 A TEXT-BOOK OF GRASSES Both these systems are attempts to furnish green feed without turning the animals out to pasture. These systems are most used and have reached their highest develop- ment in connection with dairying. The advantages are that the quantity and kind of material fed can be controlled, that there is less waste than in pasturing, that crops can be utilized which would be impracticable for pasture, and that stock are saved the work of traveling about in search of food. Silage still further has the advantage of continu- ing the supply of green feed through the winter. 75. Soiling—The practice of soiling is well adapted to intensive farming. When the price of land is high it is usually more economical to raise large crops of forage on well-fertilized fields and feed green than to have pasture, since the latter can not produce so great a quantity of feed. On the other hand the labor required for soiling is much greater. The vost of labor compared with the price of the products as milk or beef, determines the system to use. By proper care in selecting crops, a continuous yield of green forage may be obtained through a large portion of the growing season. Many crops are used for soiling, but in the main they are annuals and often succulent plants. They include the grains, the succulent grasses, such as corn, or sorghum, and the annual legumes mentioned before (Par. 63). Peren- nial grasses and clovers may also be used, but the advan- tage is less, as they do not give so large a yield as do annuals. Teosinte and pearl millet are used locally with success, the former giving, on the rich moist valley lands of Louisiana, enormous yields of forage. 76. Silage.—In this process the green forage is placed in an air-tight receptacle called a silo. This may consist of a pit or room in a barn, or more commonly a separate, : HAY AND GREEN FEED 59 usually cylindrical structure or building. In this is placed the forage usually as it comes from a cutting machine. The material is packed tight by tramping in order to exclude as much air as possible. If necessary, water is added to facilitate the packing. If properly prepared the silage or ensilage will keep for many months. The material is canned on a gigantic scale though it has not been steril- ized. More or less fermentation takes place but not of a character to interfere with its feeding value, nor with its palatability for stock that has become accustomed to the the characteristic taste of silage. If the packing of the silo has been done carelessly the material rots and is worthless. ~ The silo is built tall and narrow in order to give greater pressure, thus packing the silage more closely. Further- more, the smaller surface exposed at the top gives less opportunity for spoiling. The top layer exposed to the air rots and must be discarded, unless the feeding is com- menced as soon as the silo is filled. The top layer may be of chaff or other material of little value. If there is a leak in the silo the silage will spoil at this point. The silo may be made of cement, brick or any other building material, but because of the lower cost is usually made of wood. It should be at least 24 feet high to give the necessary pres- sure and bulk. The silage should be fed rapidly enough to prevent the exposed upper layer from having time to spoil. For this reason it is not expedient to feed less than ten cows. It is essential to pack the silage tightly as it is placed in the silo. This forces out most of the air. The fermentation uses up the small amount of air remaining and if there are no leaks the fermentation ceases. Any kind of forage may be preserved in a silo, but the 60 A TEXT-BOOK OF GRASSES plant most used for the purpose is corn. For silage, the corn should be planted more thickly than when grown for grain. The crop should be made to yield the maximum amount of grain, rather than the largest ears. The corn should be cut when the grain is glazed, as at this stage there is the maximum amount of dry matter. In the North, varieties should be chosen that will reach the glazed stage before frost. (See Farmers’ Bulletin No. 556.) ae CHAPTER VII LAWNS A LAWN is an open area covered with grass and kept closely mown. The term is applied especially to tracts near dwellings, but may be applied to closely mown areas near other buildings or in parks. Other plants than grasses are occasionally used, wholly or in part, such as white clover. The lawn is primarily for ornament, com- plete in itself or part of a general place in landscape gardening. 77. Essentials for a lawn.—An ideal lawn consists of a firm even sod supporting a vigorous growth of vegetation of uniform texture and pleasing color, the whole kept closely mown. With rare exceptions the conditions can be supplied only by grasses. A grass to be suitable for lawns should propagate by rootstocks or stolons, should be fine and soft in texture, and should be dark green in color. The most popular lawn-grass is Kentucky blue- grass. The only other grasses that fulfil the requirements mentioned are Rhode Island bent and creeping bent, both varieties of redtop. Another important lawn-grass is Bermuda-grass. Several other grasses are used for special conditions (Par. 81). 78. Blue-grass is an ideal lawn-grass throughout the region to which it is adapted. It thrives best in a moist moderately cool climate and on limestone soils. Blue- grass forms a firm even sod which, under proper conditions and treatment, is permanent. The texture is fine and (61) 62 A TEXT-BOOK OF GRASSES soft and the dark green color is agreeable to the eye. It can be grown successfully without irrigation in the north- eastern states as far south as Virginia and Tennessee, and farther in the mountains, and west to Minnesota and eastern Kansas, also in the humid region of Oregon and Washington, and in the western mountains. Throughout most of the northern half of the United States beyond the limits mentioned it can be grown with the aid of irrigation. Even in the humid region it may be necessary to supply water during the dry periods in the summer. In the southern half of the United States, except in the mountains, blue-grass does not thrive even when irrigated, although, except in the lower coastal plain, it may with special care make a fair growth. In the humid region it may fail because of the character of the soil. Thriving best on limestone soils, it fails to giye good results on acid soils. Hence, blue-grass is not adapted to much of the coastal region from New England to Virginia. Often it is practicable to correct the soil acidity by the addition of lime. 79. Rhode Island bent is especially adapted to that portion of the humid region in which blue-grass fails because of soil acidity, as it thrives under moist, moder- ately acid conditions. Rhode Island bent does not pro- duce vigorous creeping rootstocks as does blue-grass, but nevertheless will form a fairly firm and uniform sod. For a description of Rhode Island bent and its relation to redtop, see Par. 234. Creeping bent is another form of redtop, with creeping or stoloniferous stems, which pro- duces a lawn of good color and texture. 80. Bermuda-grass answers all the requirements of an ideal lawn grass except that of color. To many people the light gray-green color is not so pleasing to the eye as LAWNS 63 the dark green of the blue-grass. In the southern portion of the United States where the climate is too hot in sum- mer for blue-grass, Bermuda-grass is the common lawn- grass, except in certain localities along the coast. It is the only lawn-grass that will withstand the summer condi- tions on the uplands of the South. The foliage is not resistant to frost, hence lawns turn brown or yellow in winter, but the plants are not killed except by greater cold than usually prevails south of Virginia. St. Lucie- grass is a variety of Bermuda especially adapted to lawns, as it is fine in texture. This form is much used in Florida. 81. Less important lawn-grasses.—St. Augustine- grass is a coarse-leaved species used on moist, mucky soil of the lower coastal region. It is in use as far north as Wilmington, North Carolina. As the seed is not on the market it is propagated by cuttings. Carpet-grass is another species, with. comparatively coarse foliage and creeping or stoloniferous stems, adapted to the moist region of the Gulf coast. It occurs naturally there and tends to invade the open moist grassland of pastures and lawns. The seed is not on the market but the plant may be propagated by cuttings. Canada blue-grass is sometimes used on sterile clay or lime-poor soils of the humid regions, where blue-grass does not thrive. Fescue grasses are rarely used alone but are often sown in mixtures. Various-leaved fescue is used under trees on lawns as it thrives better than other grasses in partial shade. All the fescues used for lawn mixtures, red fescue, hard fescue, sheep’s fescue, firm-leaved fescue and various-leaved fescue have short, firm leaves that require little cutting, but they are all bunch grasses and it is diffi- cult to produce with them a uniform turf. ] 64 A TEXT-BOOK OF GRASSES Buffalo-grass gives excellent results in the semi-arid region of the Great Plains. The seed is not on the market but the grass is easily grown from cuttings. It forms a firm sod like Bermuda-grass and has the same objection of being light green in color. Buffalo-grass requires no mowing as the foliage remains short and curly. Rye-grass is sometimes used for lawns though it pos- sesses few of the necessary characteristics. It is used chiefly in mixtures to produce quick results as it grows vigorously the first season. It is coarse and bunchy and not suited to a lawn when sown alone. Korean lawn-grass is coming into use along the coast from South Carolina to Florida. 82. Lawn mixtures.—One of the characteristics of an ideal lawn is uniformity of texture. This can be obtained only when a lawn is made up of a single species. To pro- duce a lawn of uniform texture requires special care. From the standpoint of practicability it may not always be convenient or even possible to fulfil the con- ditions necessary for an ideal lawn. Hence, the use of mixtures by which better results in some ways may: be obtained than by using a single species. This applies particularly to the humid regions. The character or con- dition of the soil may be such as to prevent the produc- tion of a uniform stand of a single species. It is well known that a properly chosen mixture will in these cases produce a thicker turf and will do so in a shorter time than if a single species is grown. The chief or even the only objection to a mixture is the lack of uniformity. A closely mown lawn will show variations in color corresponding to the different species of which it is composed. Rye-grass is sometimes included in a mixture to give quick returns, the other components LAWNS 65 developing later. Grain, especially rye, may be used for the same purpose. This practice is not to be recom- mended if a first-class lawn is desired. It is to be looked upon as a makeshift to take the place of careful prepara- tion of the soil. White clover is often used in mixtures, the only dis- advantage being that it interferes with the uniformity of appearance. On the other hand, it has a distinct advantage in that it acts as a soil renovator and tends to maintain its fertility, this being due to the presence of nitrogen-fixing nodules on the roots (Par. 15). 83. Preparation of the soil.—It is necessary that the soil intended for a lawn should be placed in the best pos- sible condition for receiving the seed. It should be ren- dered light and porous to the depth of 10 inches or more by suitable tilth, should be well drained, and should be of the best consistency, that is of the combination of sand, clay and humus known as rich loam. It is usually neces- sary in addition to thorough tillage to fertilize the soil. Well-rotted barnyard manure, free from weed seed, is the best fertilizer, but not always easy to obtain. Com- mercial fertilizer may be used alone or with barnyard manure, the amount depending on the nature of the soil. Poor soil may take 400 pounds an acre of bone-meal. Wood-ashes supply potash and render heavy soils lighter. Lime should be added when necessary to counteract acidity if blue-grass is to be used. 84. Seeding—Only the highest grade seed should be used. There is great variation in the weight of blue-grass seed, depending on the proportion of chaff. Good seed should weigh about 22 pounds to the bushel. Of such seed three bushels should be sown to the acre. The seed should be sown evenly and rolled or lightly raked in. The E 66 A TEXT-BOOK OF GRASSES seeds are small and should not be covered deeply. It is important to keep the lawn as free as possible from weeds while becoming established. After the grasses have formed a firm sod or turf, weeds have little chance to intrude. If the soil and the applied manure be free from weed seeds, the task of weeding during the first season will be much simplified. 85. Subsequent care.—The lawn should be frequently mowed, watered, weeded, and rolled if it is to be brought to its maximum effectiveness. If unfavorable circum- stances have caused the death of the grass in spots or if in small areas the grass failed to grow, here the weeds appear later. Such spots should be reseeded. It is much easier to obtain a uniform stand at the first sowing than to patch up afterward an irregular stand. Some weedy grasses make a good appearance early in the season but later die out, leaving unsightly bare patches in the sum- mer. This is true of crab-grass and annual blue-grass (Poa annua). 86. Watering.—Blue-grass lawns usually require for their best development more water than is supplied by the natural rainfall. This is especially true during the dry periods that usually occur during summer. Artificial watering by garden hose is the usual method of meeting the deficit. The water should be applied in the late after- noon or evening as damage may result from watering dur- ing the heat of the day. Water should not be applied in full force direct from the nozzle, as the soil may be washed away from the roots. A spray nozzle prevents this. Thorough soaking from time to time is better than more frequent light sprinkling. Light and frequent sprinkling encourages a shallow root-system, readily injured by drought. LAWNS 67 87. Turfing—On account of the care and trouble necessary to seed a lawn it is a common practice in cities to produce results quickly by laying on fresh turf cut from an old grass plot. If properly done this will give good results. The turf or sod should be pure grass free from weeds and should be laid on well-prepared, rich, loamy soil such as described under seeding. The custom of apply- ing a layer of vegetation, part grass and part a miscellane- ous collection of weeds, to a soil consisting of the refuse from the building operations will never give satisfactory results. Such a lawn is a permanent source of regret and no amount of faithful watering can materially improve it. It is better to dig it up and start again in the proper manner. (See Farmers’ Bulletin No. 494.) CHAPTER VIII GRASSES FOR MISCELLANEOUS PURPOSES BesIpEs the three chief uses of grasses, there are others of considerable but comparatively minor importance. These uses will be considered under the following heads: Ornamental grasses, Soil-binders, Sugar-producing grasses, Textile grasses, and other uses. ORNAMENTAL GRASSES 88. Grasses may be grown for ornament because of their handsome inflorescence, such as that of the plume- grasses, or the alleged beauty of the foliage, such as that of the ribbon-grass and other grasses with variegated leaves. Some are used for making dry bouquets, the delicate inflorescence holding its form after being detached. There are three large species that are commonly used for lawn decoration. They are plume-grass, giant reed, and Kulalia. Plume-grass has long narrow leaves taper- ing to a fine point and a large white or pink feathery plume 1 to 2 feet long. The leaves are in a large cluster at the base and the plume is raised on a tall slender stalk several feet high (Par. 246). Another plume-grass less frequently seen in America is the Ravenna-grass (Par. 206). Giant reed has broad leaves scattered along the stem as in corn, and a large oblong plume (Par. 247). Eulalia has clusters of long narrow leaves at the base and a slender stalk rising a little above the leaves, bearing (68) GRASSES FOR MISCELLANEOUS PURPOSES 69 rather small (6 to 12 inches long) fan-shaped brownish plumes (Par. 204). Another grass of this habit, Thysolena agrostis, is often grown in the tropics. A common orna- mental garden grass is ribbon-grass or gardener’s garters. Several small grasses are grown for bouquets, such as trembling or quaking grass. 89. The bamboos are important ornamentals in the tropical regions and are much cultivated in Florida and California. A few species are hardy farther north. Among these may be mentioned Arundinaria japonica, a shrubby form growing 5 to 10 feet high, and certain species of Phyllostachys. There are several species of Phyllostachys introduced in cultivation but their specific identity is in doubt as many have not been known to flower. SOIL-BINDING GRASSES 90. In order to prevent banks and slopes from wash- ing or sand-dunes from blowing, they may be planted with grass or other vegetation. Such plants are known as soil-binders. More particularly, those that hold sand- dunes in place are called sand-binders. Any kind of vegetation will hold soil or sand in place, but plants used by man for this purpose are provided with strong creep- ing rootstocks that quickly penetrate and bind the soil. Grasses most frequently used for the holding of banks and slopes are Bermuda-grass in the South and Kentucky blue-grass in the humid region. The giant reed is used along irrigation ditches in the Southwest. Japanese honey- suckle (Lonicera japonica Thunb.) is proving excellent for holding slopes in Maryland and Virginia. 91. Sand-dunes.—The fixing of shifting sand-dunes is an important industry in Europe where much waste land 70 A TEXT-BOOK OF GRASSES has been reclaimed. In the United States there are several areas of sand-dunes, the most important being on Cape Cod near Provincetown, Cape Henry, Virginia, along the south end and east side of Lake Michigan, and along the Columbia River, Oregon, in the semi-arid region. Sand- dunes are formed by the wind blowing the dry sand. Dunes that are bare of vegetation shift gradually as the prevailing wind blows the sand over the crest. When vegetation becomes established the wind is unable to move the sand and the dunes become fixed. Moving dunes may do much damage when formed in the vicinity of the works of man by covering up buildings or railroad tracks, or, when formed near streams or harbors, by diverting the course of the one or filling the other, or when formed near a forest which they may over- whelm. Sand-dunes are formed along the sandy shores of the ocean or of large lakes when the prevailing winds are from the water. The waves are constantly throwing up sand which, when dry, is blown upon the beach, form- ing hills. The same often occurs along rivers in dry regions, as along the Columbia above the Dallas, and along the Arkansas in western Kansas. 92. Reclaiming sand-dunes.— Moving dunes are worthless for agricultural purposes and may be a menace to property. The first step in reclaiming such dunes is to fix the sand by applying a covering to prevent its being shifted by the wind. Interior dunes have been success- fully fixed in Europe by covering with cut heather, a common plant in sandy wastes. In other places brush or rows of sticks thrust into the sand have served the pur- pose. One of the most successful methods has been the planting of beach-grass. After the shifting of the sand has been prevented by any of these methods, trees are GRASSES FOR MISCELLANEOUS PURPOSES 71 planted which in time produce a forest, the dunes being thus permanently fixed. The waste land has now become productive, as the forest under proper care yields an income. The trees cannot be started on the shifting sand. 93. Sand-binders——Except near the seashore the function of grass or of an inert covering is temporary, as the land is ultimately converted into forest. Along the seashore where a barrier dune is formed the action of the spray from the ocean prevents the growth of trees. On this barrier dune which protects the forest in the rear from. the aggressive action of the sand, the grass covering must remain indefinitely and must be kept in condition by con- stant attention after it is planted. A sand-binder must be a plant that will thrive in the sand, and that possesses an abundance of vigorous creeping rootstocks that will bind the sand and prevent its being blown by the wind. The best sand-binder is beach-grass, or marram-grass (Ammophila arenaria), a native of the sea beaches of Europe and of Atlantic North America as far south as North Carolina. It is also found along the shores of the Great Lakes. An important char- acter of beach-grass is that it thrives best where the sand is drifting. Here it continually rejuvenates and grows up through the sand as it is covered. A few other grasses have been tried but none give as good results. 94. Fixing sand with beach-grass.—Beach-grass is propagated by transplanting and not from seed. The planting is best done in the fall between maturity, which is about September, and the time when the ground freezes. It can also be done in spring before growth starts. Plants for the purpose are chosen from a nearby plot where the grass is growing vigorously. Those chosen should be two years old and should have one or two nodes on the root- 72 A TEXT-BOOK OF GRASSES stock at the base. It is from these nodes that the roots spring. The planting is best done on a cloudy day. A hole is made by thrusting a spade or other sharp imple- ment into the sand, the plant is placed in the opening and the sand pressed around it with the foot. If beach- grass does not grow in the vicinity, it may be necessary to establish a preliminary plantation. It is useless to attempt to grow beach-grass in interior arid regions. - In America, notable fixation work has been done near Provincetown, Massachusetts, at Manatee and other points along the east shore of Lake Michigan, and at Golden Gate Park, San Francisco. The latter place was once a sandy waste but is now a beautiful park. The pre- liminary steps here were the planting of beach-grass. (See Bur. Pl. Ind. Bulletins Nos. 57, 65.) SUGAR-PRODUCING GRASSES 95. The sugar of commerce is obtained from four sources, sugar-cane, sugar beet, sorghum, and sugar maple. The amount from the last two is comparatively insignificant. Chemically, commercial sugar is cane-sugar or sucrose. 96. The sugar-cane is a large perennial grass grown in all tropical countries. In the United States its growth is chiefly confined to the lowlands of Louisiana. This state in 1900 produced 132,000 tons of sugar. The same year the two largest sugar-producing countries yielded, Java 650,000 tons, and Cuba 440,000 tons. These figures refer to sugar from sugar-cane.* It is interesting to note that Europe produced the same year over 4,000,000 tons of beet-sugar, or a third more than the total world produc- tion of sugar from the cane. The thirteenth census report *Sadtler, Industrial Organic Chemistry, ed. 3, pp. 166, 167. idee GRASSES FOR MISCELLANEOUS PURPOSES 73 states that in 1909 Louisiana produced 4,941,996 tons of sugar-cane, which was an increase of 57 per cent over that produced in 1899. Sugar is contained in the juice of the cane, this being extracted from the stalks by crushing between rollers. The juice is neutralized with lime, boiled and clarified, and concentrated in vacuum pans. The sugar separates in crystals. The remaining liquid is called molasses. Rum is made by distilling fermented molasses. The sugar-cane often flowers abundantly in the tropics, but rarely produces seed. It is propagated by cuttings of the stem. 97. Sorgho, or sorghum.—As indicated in Par. 57 there are several varieties of sorghum, some of which, the saccharine sorghums, have a sweet juice containing enough cane-sugar to make the extraction a commercial possibility. In the region from Kansas to North Carolina a small amount of sorghum is grown for the production of sugar, most of which appears on the market in the form of syrup. | The total amount of sorghum syrup produced in the United States in 1909 was 16,532,282 gallons.* The five leading states were Kentucky, 2,733,683; Tennessee, 2,076,339; Missouri, 1,788,391; Arkansas, 1,140,532; North Carolina, 1,099,346. TEXTILE GRASSES 98. The most important textile grass is esparto, the fiber of which is used for paper and cordage. It is grown chiefly in Spain and North Africa. In Algiers the grass is called alfa. Annually there are imported into England over 200,000 tons of esparto te be used for the manufacture of paper. Two species of grasses furnish the esparto of commerce—Stipa tenacissima and Lygeum sparteum. *13th Census, 74 A TEXT-BOOK OF GRASSES OTHER USES 99. The bamboos are of vast importance to the native people of the regions where these gigantic grasses grow. The culms or stems are used for building purposes, the split bamboo is woven into mats, screens and a variety of other articles, the sections of the stems with the solid partitions are used as utensils, and the fiber is used for paper. The wood is extremely hard, durable and flexible. The bamboo is probably put to a greater variety of uses than is any other plant. The straw hats known on the market as Bangkok hats are made from bamboo. Ischemum angustifolium is used in India as a substi- tute or adulterant of jute for cotton baling for the Ameri- can trade. Rice straw is extensively used in Japan and other eastern countries for matting, a large proportion of the wrapping of heavy freight being of this material. Rice is also used for paper, although the so-called rice- paper is made from the bark of the paper mulberry. The straw of grains is used for making straw hats, an especially fine quality being used in Italy. 100. Green-manuring.—Grasses, especially the grains, are used, as are legumes and some other plants, for green- manuring. For this purpose, the plants are turned under by plowing about the time they reach maturity. Heavy soils are made lighter, since the green vegetation tends to produce humus. It is usually more profitable to combine green-manuring with pasturing as one can scarcely afford to give up an entire season to a crop for turning under. Furthermore, land that most needs the manure will give the smallest crop to turn under. Stable manure accom- plishes results much sooner, but, of course, is not always available. (See Farmers’ Bulletin No. 278.) CHAPTER IX WEEDS A WEED is a plant troublesome to man. In the more restricted sense it is an herbaceous plant that becomes aggressively troublesome in cultivated fields. Plants may become weeds because of their intrusiveness, as bindweed (Convolvulus arvensis L.) and Canada thistle (Cirsium arvense (L.) Scop.) or they may be able quickly to occupy waste land, dooryards, or roadsides, as knot- weed (Polygonum aviculare L.), horseweed (EHrigeron canadensis L.) and ragweed (Ambrosia trifida L.). Others may become weeds in pastures because, not being eaten by stock, they thrive at the expense of the palatable species. ~101. Classes of weeds.—Weeds may be divided into three classes according to method of growth. These are annuals and biennials, perennials with crowns, and peren- nials with rhizomes or creeping roots. Methods of eradi- cating depend upon the group to which the weed belongs. Annual weeds may become abundant, but are not difficult to eradicate as they may be pulled up or removed by cultivation. Perennial weeds with crowns are usually not aggressive but may become conspicuous in pastures, especially those that are over-grazed. Certain kinds of plants usually classed with this group differ in having an upright fleshy caudex capable of producing adventitious buds and shoots. These may become troublesome weeds in pastures or lawns. The dandelion (Taraxacum Taraxa- (75) 76 A TEXT-BOOK OF GRASSES cum (L.) Karst., 7’. officinale Weber.) is a familiar exam- ple of this group. Cutting off the plant below the crown does not destrdy the dandelion, as adventitious buds may be produced on the cut root from which new shoots develop. 102. Perennial weeds with creeping rhizomes or creep- ing propagating roots include the most troublesome species, as the widely spreading rhizomes or roots are difficult to remove completely from the soil. Portions of the rhizomes remaining in the soil may give rise to new shoots. Creeping propagating roots are to be distinguished from creeping rhizomes or rootstocks, which are modified stems. Creeping roots possess no scales or modified leaves, but have the structure of roots. They will, how- ever, if they are propagating roots, have the power to produce adventitious buds. Some weeds with creeping roots are bindweed (Convolvulus arvensis L.) and sheep sorrel (Rumex Acetosella L.). None of the weedy grasses possesses creeping roots. Creeping rhizomes indicate their character as modified stems by the presence of scales that mark the nodes at regular intervals. To this group belong the white morning-glory (Convolvulus Sepium L.), the nut-grass (Cyperus rotundus L.) and Johnson-grass. 103. Weedy grasses.—Grasses may be of all degrees of weediness. Many species that are classed as weeds are harmless since they are found only in waste places or along roadsides. Among these are goose-grass, crowfoot- grass and old-witch grass. Only a few of the more impor- tant weedy grasses will be mentioned here. 104. Annual weeds.—In the eastern states the com- mon species are green foxtail, yellow foxtail, and upon sandy land, the sandbur. Here, and more especially in the South, crab-grass is a common weed. All these yield readily to cultivation. Crab-grass is particularly trouble- WEEDS 77 some because it thrives late in the season after the usual cultivation of the crops has ceased. Two important weeds in blue-grass lawns are crab-grass and annual blue- grass. The latter thrives in the spring, making an appear- ance pleasing to the eye, but later dies, leaving unsightly bare spots. In the same way crab-grass, later in the season, leaves brown patches as the plants die. 105. On the Pacific coast other species of grasses become weeds. A very noticeable group are the annual species of Bromus. They are of some value as forage when young but soon become too dry and prickly from the awns of the inflorescence to be palatable. The principal species are Bromus commutatus, B. hordeaceus, B. rubens, B. tectorum and B. villosus (Par. 260). Another species, B. secalinus, the common cheat or chess, is found in grain fields throughout the northern United States. The wild oat is abundant on the Pacific coast in grain fields and on fallow lands, but possesses a mitigating character in that it can be used for hay (Par. 239). Several weedy species belong to the genus Hordeum, the inflorescence of which possesses numerous rough awns that are troublesome when mixed with hay. There are three annual species, H. pusillum, H.Gussoneanum and H. murinum. The last is a common weed in alfalfa fields where it is called fox- tail and barley-grass. 106. Perennial weedy grasses—Of the group that lack creeping rhizomes there are few that are troublesome. One of the worst of them is Hordeum jubatum, which in the West often infests alfalfa fields. It is called squirrel- tail-grass, but locally is known as foxtail in Wyoming, barley-grass in Utah, and tickle-grass in Nevada. Many species become conspicuous in overgrazed pas- tures or ranges because not eaten readily by stock. To 78 A TEXT-BOOK OF GRASSES this group belong the spear grasses, species of Aristida, whose sharp fruits with the triple awns become a nuisance or even a serious pest. These fruits and others such as those of Hordeum and Sitanion work their way into the nostrils and eyes of animals and into the wool of sheep, or form hair-balls in the stomach. 107. The seriously troublesome weeds in cultivated soil are those possessing creeping rhizomes. There are three species of grasses that belong in this category. They are Bermuda-grass, Johnson-grass and quack-grass. Bermuda-grass has already been mentioned (Par. 28). In cultivated soil the rhizomes become large and vigorous and the plant is usually known then as wire-grass. Ber- muda is a common weed in corn and cotton fields through- out the southern states. Johnson-grass is exceedingly troublesome in the black soils of the southern states (Par. 49). Quack-grass is a bad weed in the humid region of the northeastern states. It is also called quick-grass, quitch-grass and couch-grass. These three species, like all weeds with rhizomes, cannot be eradicated by pulling them up or by cultivation unless all of the rhizomes are removed, since a single piece of rhizome may give rise to a shoot. They may be greatly reduced in this way, however. On a large scale they may be kept in subjection by plowing and harrow- ing out the rhizomes, after which they are burned or removed or spread so as to be dried out by the sun. Another general method for eradicating such weeds is to smother them with a vigorous crop, such as grain or alfalfa. Small patches may be attacked to advantage with the hoe, cutting off all the green shoots. If this is done frequently the rhizomes are exhausted of their vitality and are unable to produce more shoots. CHAPTER, X GRASS-CROP AREAS In previous chapters, reference has been made under each grass crop to the area in the United States in which it thrives. In this chapter a résumé will be given of the conditions and limitations of these areas. The crop areas depend entirely upon climatic conditions. Soil conditions modify or limit the distribution of crops within each area. So far as crops are concerned, the climatic conditions are moisture and temperature. 108. Moisture——The moisture, so far as it concerns crop areas, depends on the annual rainfall and its seasonal distribution. Locally crops may receive water by seepage from rivers and springs but such sources have no effect on the general distribution of crops. The seasonal dis- tribution of the rainfall is of as much importance as the annual rainfall, for the crops require water during the growing season. The amount of water required by a crop varies with the evaporation, which depends in part upon the humidity. Without going into the physical and meteorological details, it will readily be understood that latitude and altitude modify greatly the relation between a crop and its water-requirement. There is also an inti- mate connection between temperature and rainfall. Soil conditions modify the water requirement in various ways, but not sufficiently to have any material effect on the large crop areas. 109. The temperature affects evaporation and hence (79) 80 A TEXT-BOOK OF GRASSES the water-requirement. It also affects directly the growth of crops. There is an optimum temperature for each crop at which it thrives best. The temperature through the growing season is of the most importance, though for perennials the minimum winter temperature may be a limiting factor. 110. The timothy area.—This area extends from New England to the southern boundary of Virginia and farther south in the mountains and west to Minnesota and east- ern Kansas, approximately to the 96th meridian. In general this is the humid area. The rainfall is sufficient on the average for the growing, without irrigation, of the common meadow- and _ pasture-grasses, timothy and blue-grass, and the legume, red clover. The rainfall is distributed through the summer or growing season. There are other humid regions in the United States in the mountains of the western portion, isolated areas where the rainfall is sufficient and the altitude not too great. Timothy can be raised in Colorado up to about 9,000 or even 10,000 feet altitude. At higher latitudes the altitudinal limit is lower. The most important humid | region of the West is the upper Pacific coast region lying west of the Cascades and extending from Puget Sound south into northern California. This differs from the eastern humid region in having cooler summers and milder winters with considerable rainfall. This region is emi- nently adapted to pasture crops because of the mild, moist winters. It is not so well adapted to hay crops because of the difficulty of curing hay in the moist climate. (See Farmers’ Bulletin No. 271.) In the northern part of the timothy area, the Canada field pea is much used (Par. 67). In the eastern part along GRASS-CROP AREAS 81 the coast where the soil is often acid, redtop becomes the dominant forage grass (Par. 32). 111. The Bermuda-grass area—This area occupies the region south of the timothy area and wes .o include eastern Texas. Approximately this is also the cotton region. The annual rainfall is sufficient for such forage plants as timothy and clover but the summers are too long and hot for the development of these crops. Some of the annual plants of the timothy region such as the grains, vetches, and crimson clover, can be grown in the south as winter forage crops. The rye-grasses, though short-lived perennials, can be treated as annuals and will give good results when sown in the fall for winter forage. (See Far- mers’ Bulletin No. 509.) 112. The Great Plains—This is the area lying between the Rocky Mountains and the two areas mentioned above and extending from north to south across the United States, and beyond its boundaries in each direction. The annual rainfall along the eastern border is about 30 inches. This decreases westward until it is about 15 inches at the base of the mountains. This amount is too small for the production of crops adapted to the humid region but many specially adapted crops can be raised without irrigation in the eastern half of the belt. The region is devoid of forest except along the streams of the eastern part. Before the land was occupied by man these plains were covered with grass, the dominant species being buffalo- grass, grama-grass and curly mesquite, all low grasses that form a close sod. The early settlers used the sod to make sod houses. The Great Plains are eminently adapted to stock- grazing and there are throughout, but more particularly in the western part, numerous large stock ranches. The F 82 A TEXT-BOOK OF GRASSES water of the comparatively few streams is supplemented by wells, many of which are over 100 feet deep, and by dams in the ravines or “draws” that catch and hold the run-off from the storm water. The rainfall may come in torrential storms and much of the water, instead of being absorbed by the soil, runs off in the watercourses and is lost to the area. The native vegetation has already been described (Par. 23). 113. Forage crops for the Great Plains—Within recent years a large part of the eastern half of this belt has been converted into farms, and much of the native sod has been placed under cultivation. As modern methods for dry-farming come into more general use, and crops especially adapted to dry regions are more widely grown, more and more of the Great Plains will be utilized for the growing of crops. In the western part of the belt irriga- tion is practised in many places either by ditches from the larger rivers, as the Platte and Arkansas, or from deep wells by means of windmills or gasoline engines, or from ponds that catch the storm water. The forage crops adapted to this region are millet (Par. 56) for the eastern half of the belt; brome-grass (Par 31) for the region from Nebraska to Montana and Minnesota; and the sorghums for the region from Kansas to Texas. Kafir is grown for grain and forage. It is usually planted in rows and culti- vated. Saccharine sorghums, such as the Amber and Orange varieties, are much grown for hay. For this purpose they are sown thickly and mowed with a machine. The grains grown for the seed over the eastern and central portion of the belt furnish also no inconsiderable amount of forage. It is a common practice in the winter wheat region to pasture the wheat fields in the fall and early winter. The most important forage crop is alfalfa. GRASS-CROP AREAS 83 With proper care in preparation of the soil and in seeding, this leguminous crop can be grown without irrigation over a very considerable portion of the area. 114. The arid region.—This includes all the region west of the Great Plains where the rainfall is insufficient for the growth of crops without the aid of irrigation. Besides the two main mountain systems, the Rocky Mountains and the Sierra Nevada, there are numerous smaller ranges throughout the region between. The term Great Basin strictly applies to that portion such as most of Utah and Nevada which has no drainage to the sea, This name is often applied in a loose way to the whole region between the two mountain systems mentioned. The general level of this interior region is at 4,000 to 5,000 feet altitude. Usually at higher altitudes in the mountains the climate is increasingly moist. Above about 8,000 feet the climate is usually humid and the slopes are in general more or less forested. The climate of the plains and valleys is arid. Crops are raised only as water for irrigation can be obtained from the streams. Much of the area is sufficiently arid to be called a desert. This is especially so in the southern part where the summers are longer. Under favorable conditions crops can be raised by applying the methods of dry-land farming. Such may be the case at the base of a mountain slope where there is sub-irrigation through seepage from the mountain. The great proportion of this arid region is used for stock-grazing in so far as it can be used at all for agricultural purposes. Most of the grazing is in the mountains but there is some forage on the desert which is utilized if water for stock is available (Par. 20). Where there is snow in winter, sheep can be pastured, the animals depending on the snow for their water-supply. 84 A TEXT-BOOK OF GRASSES 115. The Pacific slope—tIn the great interior valley of California and northward through eastern Oregon, eastern Washington and northern Idaho, the rainfall comes mostly in the winter, this season being comparatively mild. Under these conditions the winter season is adapted to the growth without irrigation of annual crops such as grain. The summers are hot and dry, and irrigation is necessary for summer crops such as alfalfa. The region to the northwest of this is humid (Par. 110). 116. The relative importance of the different kinds of forage in the different regions of the United States.— The production (tons) of the kinds of forage mentioned by the thirteenth census report is given in the following table, each being arranged by states. The production of each kind of forage in the United States is shown in Figs. 2 to 10. TABLE XVII Tue Propuction (Tons) oF Hay anp ForAGE FoR 1909, BY THE TEN LEADING StTaTEs, OF Eaco KInp oF FORAGE Timothy 1. Ohio . 2,348,660 6. Pennsylvania . . 1,200,073 2. Iowa . 1,952,956 7. New York . 1,159,083 3. Illinois . 1,947,572 8. Wisconsin . 1,110,446 4. Indiana . . 1,442,218 9. Minnesota . 1,101,510 5. Missouri . 1,334,556 10. Michigan 929,165 Timothy and clover mixed i Towa |. . i -9s, Sloe Lee 6. Missouri . 1,630,211 2. New York Pa SB | 7. Minnesota . . 14sec are 3. Wisconsin . 2) aye ake 8. Ohio . 1,346,347 4. Michigan . 1,991,618 9. Illinois . 1,123,254 5. Pennsylvania . 1,830,852 10. Vermont 628,098 Clover alone 1. Illinois ;. 539,790 6. Tennessee . . 201,926 2. Indiana . 314,818 7. Iowa . . 195,579 3. Missouri . 309,209 8. Wisconsin . . . 193,786 4. Ohio : . 239,492 9. New York . . . . 114,864 5. Michigan . . . 216,862 10. Minnesota. . . 106,334 or He CO ND or BR OO ND cr me oo ND ee or yh Oo ND Or OO ND eH ORWNE . Kansas . California . . Nebraska . Colorado Idaho. . Kansas Nebraska North Dakota Missouri Texas . New York Maine Tennessee . Minnesota Vermont . Nebraska . South Dakota Minnesota Wiech Dakota’ . . Kansas . California . . . Oregon . Washington . . Idaho Tennessee . . New York . Kansas Texas . Wisconsin . lows <> GRASS-CROP AREAS TaBLE XVII, continued Utah : Montana . Wyoming . Oregon . Washington Tennessee Oklahoma South Dakota Iowa Alfalfa . 1,998,689 6. 1,639,707 a. 125225136 8 1,265,915 9 964,529 10 Millet or Hungarian grass . 290,661 6. . 160,684 v2 149,429 8. 141,626 9. S5.452. ‘10: Minnesota Other tame or cultivated grasses . 412,479 . 258,789 . 218,482 / 188,371 160,014 6. rid 8. 9. : 10. New Hampshire Connecticut Massachusetts Kentucky Texas Wild, salt, or prairie grasses Iowa Oklahoma Montana Wisconsin Colorado South Carolina Georgia Louisiana North Cnenlian ; Illinois Vermont Ohio Pennsylvania Minnesota . Michigan nee UOT Soo 6. . 2,798,263 7. gt 1A TD 8. » 2si2G1s 9. . Disitpos- Te. Grains cut green . 2,019,526 6. 509,030 i. 499,955 8. 140,098 9. 136,674 10. Coarse forage . 1,876,795 6. oe eae i. 688,274 8. 571,441 9. 510,184 10. . 791,355 . 599,747 . 397,669 . 375,445 . 357,595 . 76,311 . 75,591 . 65,844 . 54,346 . 50,383 . 159,365 . 150,723 . 139,382 138,758 131,621 1,178,000 607,120 589,860 497,622 368,408 . 133,996 128,929 . 127,126 . 118,687 99,828 . 452,461 . 443,512 . 422,925 . 401,614 . 379,279 117. Remarks on Table XVII.—In order to under- stand the classification of the forage plants in the census report, the following extract is quoted from “Instruc- 86 A TEXT-BOOK OF GRASSES tions for Clerks in Tabulation Subdivision II, Agricul- ture,” being a part of Inquiry 438, concerning hay and forage crops. (a) Tabulate as “clover alone” all crops reported after that designation, as well as all reported as “alsike,”’ ‘‘red clover,’’ ‘crimson clover;” also other clovers unmixed with other grasses. The same crops reported as mixed with timothy or herd’s grass should be tabulated as ‘‘timothy and clover mixed.’”’ When reported as mixed with grasses other than timothy or herd’s-grass, they should be tabulated as “‘other tame or cultivated grasses.”’ (b) Tabulate as “other tame or cultivated grasses” all crops reported after that designation, as well as all reported as ‘‘red- top,” ‘June-grass,” “‘orchard-grass,” “blue-grass,”’ and “Johnson- grass;’’ also all combinations of these grasses with any of the clover crops mentioned in paragraph a, preceding, or with timothy. (c) Tabulate as “‘wild, salt, or prairie grasses’’ all crops reported after that designation, as well as all reported as ‘‘marsh-grass,”’ “swamp-grass,” “slough-grass,”’ ‘‘bluestem,”’ ‘‘daisies,” and ‘“‘butter- cups.” (d) Tabulate as “grains cut green” all crops reported after that designation without specific names, or with the name “oats,” “wheat,” “barley,” “rye,” ‘‘peas,”’ ‘“cowpeas,”’ “soybeans,” “velvet- beans,” or ‘‘vetches.”” Keep a memorandum of the names of all crops reported with specific names and tabulated as “grains cut green.” (e) Tabulate as “‘coarse forage” all crops reported after that designation without specific names, or with the name ‘“‘corn’’ (see paragraph 7 below), “sweet corn,” “cane,” “sorghum,” “Kafir corn,” “Jerusalem corn,” “milo maize,” or kindred crops. Timothy and clover, alone and mixed, constitute the first three items of the classification under hay and forage. These plants are grown in the humid region (Par. 110), though the New England states, with the exception of Vermont, are not represented. Ohio, Iowa, Illinois, New York, Wisconsin and Minnesota are represented in each of the lists of ten leading states for these forage plants. GRASS-CROP AREAS 87 The leading alfalfa states are all west of the Missouri River, although it is note-worthy that the state of first rank, Kansas, lies on the eastern border of the region. With the exception of Tennessee, the leading millet states lie between the Mississippi River and the Rocky Mountains. The states leading in the production of forage classi- fied as “other tame or cultivated grasses” are those of the New England division, together with the adjacent state of New York, and the more remote states of Minne- sota, Kentucky, Tennessee and Texas. In the north- eastern states the most important element is redtop. In Texas, as in other southern states, Johnson-grass is an important factor. In Tennessee and Kentucky orchard- grass is an important forage plant. The states leading in the production of wild hay, with the exception of Wis- consin, lie in the Great Plains region where the bulk of the product is made up of mixed prairie grasses. In Wis- consin an important factor is blue-joint (Calamagrostis canadensis). Most of the elements in the classification of hay and forage represent summer-grown crops. The category referred to as “grains cut green”? assumes importance in two regions, the Pacific coast and the southern states. In the first region the best conditions for grain-growing obtain in the winter season, during which the greatest rainfall of the year occurs. Because of these conditions hay made from grain is the most available forage. In the second region cowpea hay is an important crop. Canada field pea, an important crop along our northern border, is included in the figures for ‘‘grains cut green.’”’ Under the last heading, ‘‘coarse forage,” are included corn and sorghum cut for forage. 88 A TEXT-BOOK OF GRASSES LIST OF GOVERNMENT PUBLICATIONS REFERRING TO FORAGE CROPS AND SPECIAL USES OF GRASSES The list is not complete but indicates the more impor- tant recent publications. The bulletins of the state experiment stations should also be consulted by the student. Another important series is that of the circulars and bulletins of the Division of Agrostology, United States Department of Agriculture. These bulletins are now out of print but the series can be consulted in the libraries of educational institutions. United States Department of Agriculture, Bureau of Plant I ndustry, Bulletins Nos. 4. Range Improvement in Arizona. 11. Johnson-Grass. 12. Stock Ranges of Northwestern California. 13. Experiments in Range Improvement in Central Texas. 15. Forage Conditions on the Northern Border of the Great Basin. 19. Kentucky Blue-Grass Seed. 31. Cultivated Forage Crops of the Northwestern States. 38. Forage Conditions and Problems in Eastern Oregon. 57. Methods Used for Controlling and Reclaiming Sand-Dunes. 59. Pasture, Meadow, and Forage Crops in Nebraska. 65. Reclamation of Cape Cod Sand-Dunes. 67. Range Investigations in Arizona. 72. Ill. Extermination of Johnson-Grass. 74. Prickly Pear and Other Cacti as Food for Stock. 75. Range Management in the State of Washington. 82. Grass Lands of the South Alaska Coast. 84. The Seeds of the Blue-Grasses. 94. Farm Practice with Forage Crops in Western Oregon. 100. VI. Orchard-Grass. 111. IV. Forage Crops for Hogs in Kansas and Oklahoma. 111. V. The Culture and Uses of Brome-Grass. 117. Reseeding of Depleted Range and Native Pastures. 118. Peruvian Alfalfa. 124. 127. 140. 169. 175. 177. 179. 197. 203. 209. 229. 237. 253. 258. Nos. 72. 101. 108. 139. 164. 174. 194. 246. 248. 260. 271. 279. 288. 292. 300. 312. 318. 322. 323. 331. GRASS-CROP AREAS 89 The Prickly Pear as a Farm Crop. The Improvement of Mountain Meadows. The Spineless Prickly Pears. Variegated Alfalfa. History and Distribution of Sorghum. A Protected Stock Range in Arizona. The Florida Velvet Bean. The Soybean. Importance and Improvement of the Grain Sorghums. Grimm Alfalfa. Agricultural Varieties of the Cowpea. Grain Sorghum Production in the San Antonio Region of Texas. The Kaoliangs: A New Group of Grain Sorghums. Some New Alfalfa Varieties for Pastures. Farmers’ Bulletins Cattle Ranges of the Southwest. Millets. Saltbushes. Emmer. Rape as a Forage Crop. Broom-Corn. Alfalfa Seed. Saccharine Sorghums for Forage. The Lawn. Seed of Red Clover and Its Impurities. Forage Crop Practices in Western Oregon and Western Washington. Method of Eradicating Johnson-Grass. Nonsaccharine Sorghums. Cost of Filling Silos. Some Important Grasses and Forage Plants of the Gulf Coast Region. A Successful Southern Hay Farm. Cowpeas. Milo as a Dry-Land Grain Crop. Clover Farming on Sandy Jack-Pine Lands of the North. Forage Crops for Hogs in Kansas and Oklahoma. A TEXT-BOOK OF GRASSES . Alfalfa. . Meadow Fescue. . Conditions Affecting Value of Market Hay. . Soybeans. . Irrigation of Alfalfa. . The Adulteration of Forage-Plant Seeds. . Canada Blue-Grass. . Lespedeza or Japan Clover. . Better Grain-Sorghum Crops. . Best Two Sweet Sorghums for Forage. . Eradication of Quack-Grass. . Winter Emmer. . Sweet Clover. . Lawn Soils and Lawns. . Alfalfa Seed Production. . Timothy Production on Irrigated Land in States. . Market Hay . Forage Crops for Cotton Region. . Vetches. . Vetch-Growing in the Southern States . Crimson Clover: Growing the Crop. . Kafir as a Grain Crop. . The Making and Feeding of Silage. . The Making and Feeding of Silage. . Crimson Clover: Utilization. Northwestern Articles in the Yearbooks of the Department of Agriculture . Grasses as Sand- and Soil-Binders. . Canadian Field Peas. Forage Conditions of the Prairie Region. Grasses of Salt Marshes. . Timothy in the Prairie Region. Cowpeas. . Lawns and Lawn-Making. Leguminous Forage Crops. . Millets. Sand-Binding Grasses. Grass Seed and Its Impurities. GRASS-CROP AREAS 1898. Forage Plants for Cultivation on Alkali Soils. 1899: Succulent Forage for Farm and Dairy. 1900. Our Native Pasture Plants. 1901. Grazing in Forest Reserves. 1906. Range Management. 1908. Search for New Leguminous Farm Crops. 1912. Some New Grasses for the South. 91 PART Il SYSTEMATIC AGROSTOLOGY CHAPIN Af MORPHOLOGY OF THE VEGETATIVE ORGANS Morpuo.oey treats of the form and structure of organs, especially as to their developmental relations. For exam- ple, morphological study indicates that a fundamental organ may develop into a foliage leaf, into a scale or bract, or into the parts of the flower. In order to understand the natural classification of plants, it is first necessary to be familiar with their morphology. To interpret and use descriptions, it is necessary to understand the terminology used in morphology. The subject will be considered under two heads, morphology of the vegetative organs and morphology of the floral organs. GENERAL CHARACTERISTICS OF GRASSES 118. Grasses are included in the natural botanical family Poacee or Gramineze.—They are usually distin- guished by having long narrow 2-ranked blades, clasping sheaths, small greenish flowers collected in a compact or open inflorescence. The flowers have no proper peri- anth nor floral envelopes, but consist of a pistil and usually 3 stamens inclosed between 2 small bracts. Further details will be given under the appropriate headings. There are a few other groups of plants that resemble grasses in general appearance. The natural order Poales, Graminales or Glumiflore, includes the grasses and sedges (95) 96 A TEXT-BOOK OF GRASSES (Cyperaceze). Many sedges have grass-like blades, but differ in having 3-ranked leaves and in having flowers supported by a single bract. In rushes (Juncacez) the essential organs of the flowers are surrounded by a small greenish 6-parted perianth, and the fruit consists of a capsule with several or many seeds. A few plants belong- ing to the lily family and other allied groups have grass- like blades, but the flowers possess a proper perianth that is sometimes greenish but often conspicuously colored. Familiar examples of plants belonging to the grass family are, blue-grass, timothy, redtop, wheat, rice and other grains, corn, sorghum, sugar-cane and bamboos. 119. Gross anatomy.—It is assumed that the student is familiar with the fundamental distinction between the primary organs of the phanerogams. He may be reminded, only, that the plant consists of shoot and root, that the shoot consists of the stem and leaves borne upon it, and that the inflorescence consists of modified shoots. Grasses may be annual or perennial. In cooler regions certain annual species may germinate in the fall, live over winter as a small tuft and send up flower stalks the follow- ing spring. These are known as winter annuals. 120. Perennial herbaceous species are mostly of two kinds. In the first kind a crown is formed by the per- sistent bases of the culms, the upper portions of which die back each year. The young shoots of the ensuing season are produced from buds arising within the sheaths They grow up alongside the old stems and together form a compact mass. Such grasses form tufts or tussocks and are commonly called bunch-grasses. The orchard-grass is a familiar example. Some authors refer to the shoots of bunch-grasses as being intravaginal. In the second kind of perennial, the new shoots arise MORPHOLOGY OF THE VEGETATIVE ORGANS 97 from rhizomes or rootstocks. These are modified shoots that burst through the sheaths and creep horizontally below the surface of the soil. Grasses such as the blue- grass, with well-developed rhizomes, tend to form a com- pact sod. The young shoots or innovations of such grasses are sometimes referred to as extravaginal. The various forms assumed by rhizomes will be discussed under the subject of the stem. Besides these two chief kinds of perennial grasses, there are those (such as the buffalo-grass) that produce stolons by which a sod is formed. Still another method of persisting through unfavorable seasons is found in many grasses growing in the water or mud. The lower prostrate or decumbent portion branches freely and persists while the upper portion dies back. The older portion dies sooner or later so that the original base of the plant disappears and one finds only a tangled mass of creeping and root- ing stems. The stems of grasses vary in height from an inch or less to several feet in herbaceous species. Some of the larger bamboos arise to the height of over 100 feet and may be a foot in diameter. Certain climbing species clamber up through the branches of trees to the height of 30 feet or more. 121. Distribution—Grasses are found in all parts of the world where there is sufficient soil to permit growth. They are found from the tropics to the arctic regions, from sea-level up to the limits of perpetual snow. They are found in woods, plain, swamp and desert, on the floor of the deepest forest, on the sandy seashore, in moist gorges and on rocky cliffs. In the main, however, grasses love sunlight, and are found in greatest abundance in open land such as prairies and pine barrens. In mangrove G 98 A TEXT-BOOK OF GRASSES swamps grasses are rare and in thick forest only a few broad-bladed shade-loving species are found. The species of grasses are frequently gregarious, form- ing large masses more or less to the exclusion of other plants. Familiar examples are the large areas of Indian rice and of Phragmites in swamps, and the zones of Homalocenchrus oryzoides around ponds. On prairies and plains, grasses are usually the dominant vegetation, though the species may mingle more than in the swamp plants mentioned above. During the flowering period, a particu- lar species may appear to the casual observer to be the only species present, but close examination usually proves the presence of various other species, some of which may in their turn appear dominant at another period. THE ROOT AND STEM 122. The roots of grasses are fibrous. They are usually found at the base of the plant, but in decumbent or pros- trate stems they may be produced at the nodes. Support- ing or prop roots are sometimes produced in erect stems at nodes above the surface of the soil as in Indian corn. Underground stems which may have the appearance of roots will be discussed in another paragraph. 123. The stem of grasses, known as the culm, is made up of a series of nodes and internodes. The nodes are the more or less swollen joints at which the leaves originate. The internodes when young are solid, that is, filled with pith, but at maturity the pith usually disappears leaving the culm in the form of a tube with solid partitions at the nodes. The wheat straw is a familiar example of this structure. In some grasses, such as the corn and sorghum, the internodes retain the pithy interior. MORPHOLOGY OF THE VEGETATIVE ORGANS 99 The nodes are capable of growth after the maturity of the internodes. By virtue of this character the culm is able to change its direction by bending at the nodes, the latter increasing in length on the outer side. This tendency may be observed in decumbent culms, the terminal por- tion remaining erect while the basal portion may become prostrate. In such cases the nodes first elongate on the under side and later on the upper side as the successive internodes become horizontal. The node is usually indi- cated externally by a more or less well-marked zone showing a difference in color, texture or pubescence. The swelling often present near the node is a part of the sheath and will be described in connection with that organ. In young shoots, the leaves grow at first much faster than the internodes, so that the terminal portion or bud consists of several sheaths fairly well developed, one within the other, while the corresponding internodes are very short. Later these internodes elongate rapidly, separating the leaves. By this means the youngest portion of the shoot is always well protected by the surrounding sheaths. i The culms are usually cylindrical or nearly so, but may be distinctly flattened. They are never 3-angled as in sedges. The mature culm in proportion to its weight has great strength, especially to resist bending. This condi- tion is aided by the tubular shape and by the hard tissue of the walls. In addition to the sclerenchyma fibers, so abundantly produced as to form a solid ring of tissue with the vascular bundles, there is usually deposited a con- siderable quantity of silica. 124. Duration.—The culms of most grasses are herba- ceous and die down at least to the surface of the soil. In 100 A TEXT-BOOK OF GRASSES bamboos and a few other groups (such as Lasiacis and Arundo) the culms are woody and persist many years. Transitional forms are not uncommon, especially in desert regions where the base of the culms becomes perennial, the new shoots arising from this more or less elongated and woody portion. 125. Stems modified for propagation—The usual form of propagating stem is the rhizome or rootstock (Fig. 58). Rhizomes are creeping underground stems that may be distinguished from roots by the presence of reduced leaves in the form of scales. The terminal bud is hard and sharp so that the rhizome is able to force its way through the soil. Rhizomes vary greatly in size and consistency, being slender or almost thread-like in some species and thick and firm in others, but are rarely suc- culent enough to be called fleshy. From the rhizomes are sent up the vertical shoots, sometimes a single shoot the following season, sometimes several during the same season. In sandy soil, especially on sand-dunes, the system of rhizomes reaches its greatest development. Beach-grass (Ammophila) and species of Spartina (such as S. juncea) produce a branching network, a single element of which may be many feet in length. Under favorable circum- stances of isolation, a vigorous rhizome may be traced a long distance by the line of vertical shoots produced. Swamp-grasses are usually provided with a well-developed rhizome system, by which they may form a layer over soft mud or even upon the surface of water. Grasses that grow in ordinary alluvial soil and that produce copious slender rhizomes form a firm sod and are useful for lawns. Examples: Blue-grass and Bermuda-grass. MORPHOLOGY OF THE VEGETATIVE ORGANS 101 Between species with well-marked rhizomes such as described above and species in which the rhizomes are absent there are many transitions. The rhizomes may be short and thick with the scales close together, the plants forming loose tufts. Or the rhizomes may be slender but short and ascending, the plants also forming loose tufts. In certain species, usually classed as bunch-grasses, in which the tuft grows by accretions at the outer edge, the new shoots must bend outward and upward to reach the light. In large tufts the outer shoots have decumbent bases which may simulate short rhizomes. In some cases, especially in desert regions, such tufts may assume the form of fairy rings, dying out at the center and expand- ing at the circumference, until finally the living zone breaks up into isolated tufts, each to become a new center of growth. 126. Stolons—wWhen the modified propagating stems are produced above the surface of the soil they are called stolons or runners. They differ also from rhizomes in that they bear foliage-leaves instead of scales, although these leaves are usually different in size or shape from those produced upon the foliage-shoots. Stolons are to be dis- tinguished from shoots of creeping prostrate or decumbent plants in that they are modified creeping stems, that is, they differ from the ordinary erect or ascending shoots of the same plant and have the distinct function of propagation. The buffalo-grass produces stolons so abun- dantly that the plant forms a firm sod upon large areas of the Great Plains (Fig. 48). It was from such sod that pioneers in this region made their sod houses. In the tropics stolon-producing species are more numerous than in the cooler regions. Pard-grass, when growing in new soil, produces vigorous stolons as much as 20 feet long. 102 A TEXT-BOOK OF GRASSES The common carpet-grass of our southern states produces strong stolons which, on overhanging banks or in other favorable situations, may reach a length of several feet. Some species prcduce rhizomes or stolons according to the conditions under which they are growing. Bermuda- grass forms strong rhizomes several inches below the sur- face in cultivated soil but in hard uncultivated soil pro- duces stolons, and not infrequently both may be found in the same mass of sod. 127. Corms.—Another and rarer form of modified underground stem is the corm. This is a hard globular thickening at the base of the plant. In Panicwm bulbosum, a grass found in the mountain valleys of New Mexico and Arizona, these corms are well marked, sometimes as much as an inch in diameter, and may occur in groups of several attached in one mass. Rudimentary corms are found at the base of the stems of timothy, Cinna and many species of Melica. A variety of the tall oat-grass produces corms in moniliform strings. The corms are produced by the thickening of a single internode. If there is more than one corm on the same shoot the con- striction between is the node. In Melica the thickening is greatest at the base of the internode resulting in a flask- shaped corm. Buds arise not on the corms but at the con- strictions, as these are the nodes. The masses of corms mentioned as being found in Panicum bulbosum include together with the living corms persistent old corms at the base of the stems of previous years’ growth, these being connected by short rhizomes. 128. Artificial propagation by means of stems.—Sugar- cane is propagated by planting pieces of the stems or canes, the buds at the nodes developing into shoots. Para-grass and Bermuda-grass are propagated by planting pieces of MORPHOLOGY OF THE VEGETATIVE ORGANS 103 the stolons or rhizomes. A common method in case of the latter grass is to cut sod into small pieces by means of an ax or a feed-cutter and to drop these upon prepared ground, forcing them in by pressure of the foot. Or, so readily do these pieces of stems grow, they may be sown broadcast and harrowed in or pressed in with a roller. THE LEAF 129. The leaf is a lateral organ of the stem borne singly at the nodes. A normally developed foliage-leaf consists of two parts, the sheath and the blade. The sheath envelopes the culm above the node; the blade is the long narrow flat portion to which the name leaf is often applied. At the junction of the sheath and blade is found an appendage called the ligule. Leaves are arranged on the culm alternately, in two ranks or rows. That is, the blade of a leaf at one node is on the side opposite the one below, while the third blade is above the first and on the same side of the culm. This universal arrangement, easy to observe in corn, is often obscured by the twisting of the culm or sheaths, by which the leaves may appear to be more or less in one rank or to be spirally arranged. When the internodes of a shoot have failed to elongate so that the leaves remain in a tuft or fascicle, the actual distichous arrangement of the leaves is distorted by the mutual pressure of these organs, by which they may appear to radiate in all directions. Leaves may be reduced to scales or bracts. Reduced leaves that appear on a shoot below the foliage-leaves are called scales. Those that appear above the foliage-leaves are called bracts. 104 A TEXT-BOOK OF GRASSES 130. Leaf-base and blade.—As regards development, the leaves of flowering plants consist of two portions— the leaf-base and the blade. The leaf-base is prominent in the early development of the organ, but generally includes only a small portion of the mature leaf. In the leaves of common deciduous forest trees, the swollen portion at the base of the petiole represents the leaf-base. In reduced leaves, the leaf-base often includes a relatively greater portion or may even be the only portion developed. In grasses, the sheath represents the leaf-base. In scales and bracts, the blades have failed to develop or consist ~ of a mere tip or point. 131. The prophyllum.—At the point where a branch shoot originates from a main shoot, there is produced on the side next to the parent shoot a 2-keeled organ called the prophyllum. Through pressure the back of the prophyllum between the keels is concave against the parent shoot, while the two lateral portions, outside the keels, bend forward clasping the new shoot. At first the prophyllum completely covers the young shoot or bud, but later is spread or opened as the shoot develops. The various subdivisions of the leaf will now be dis- cussed more in detail. 132. The sheath is the lower portion of the leaf that encircles the culm above the node from which it arises. From the developmental standpoint it represents the leaf-base. The sheath is usually open from the base on the side opposite the blade, the right and left margins of suc- cessive sheaths overlapping alternately. The sheath usually fits close to the stem but may be loose or inflated, especially the uppermost. The old sheaths at the base of the shoots may persist in perennial grasses and assume a characteristic appearance. MORPHOLOGY OF THE VEGETATIVE ORGANS 105 The uppermost sheath of Sporobolus cryptandrus (Torr.) Gray and allied species becomes inflated and spathe-like, more or less inclosing the inflorescence. The spathe-like sheaths are conspicuous in Andropogon Elliottii Chapm. Certain water-grasses, notably Pas- palum repens Berg., have inflated sheaths that act as floats to sus- tain the stems on the surface of the water. In some grasses, especi- ally those of dry regions, the dead sheaths persist as separated fibers or as a network of fibers. In other species such as Muhlenbergia gracilis (H. B. K.) Kunth and more conspicuously in M. straminea Hitche., the sheaths become flat and ribbon-like and persist as a curly mass resembling shavings, simulating old blades. In some species the sheaths are united by the margins to form a tube nearly or quite to the top. Examples: Bromus, Danthonia, Festuca, Melica, Panicularia. Though the sheaths normally encircle the culm, a spreading branch may pull the subtending sheath away from the culm, in which case the sheath usually encircles the branch. 133. Sheath nodes—Many grasses present at the base of the sheath a distinct swelling which at first sight appears to be the node of the culm. If this portion of the stem is split open longitudinally it is readily seen that the prominent swelling is on the sheath and that the stem node is just below as will be indicated by the cross parti- tion. The sheath-node is often differentiated also by its color or pubescence. 134. The collar— At the junction of the sheath and blade there is in nearly all grasses a distinct line of demar- kation. On the inside is the ligule (Par. 135). On the out- side or back is a line, zone or ridge which is differentiated in color, texture, markings or pubescence. This zone is called the collar. 135. The ligule is an appendage on the inside of a 106 A TEXT-BOOK OF GRASSES grass leaf at the junction of the sheath and blade. The usual form of the ligule is a membrane extending across the top of the sheath at first tightly clasping the culm, the membrane being longest in the middle portion. The shape and appearance of the ligule are characteristic of each species and are often used for taxonomic purposes. The ligule may be truncate or even somewhat concave on the upper margin. It is nerveless but may be 1-keeled (Dactylis glom- erata) or apparently 2-keeled by the extension upward of the base of the blade on each side. Not infrequently the ligular tissue extends down the margins of the sheath. Sometimes the ligule is lacerate or ciliate, or may appear as a row of hairs (Panicum Lindheimeri Nash and its allies). The ligule is obsolete in some species (Panicum sphero- carpon Ell.) and entirely absent in others (Echinochloa crus- galli (L.) Beauv.) In Anthochloa colusana (Davy) Scribn. there is no differentiation into sheath and blade, hence no collar or ligule. The exact morphology of these leaves has not been investigated. It may be the sheath that is obsolete. 136. The blade is the usually flat part of the leaf beyond the sheath and is the chief foliage organ of the plant. In most grasses the blade is many times longer than wide but in many tropical species and in a few of the temperate regions it is short and broad, from oval to lanceolate in outline (see Fig. 29). Grasses with this kind of blade are mostly confined to the damp forest regions of the tropics. In such grasses the shoots are often strongly dorsiventral, the blades being turned into the plane of the culm, and the shoots usually prostrate, procumbent or ascending. The genera Oplismenus, Ichnanthus, Senites, Pharus and many species of Panicum (as P. trichoides) furnish familiar examples of species with broad short blades that are found on the floor of tropical forests. These blades often resemble those of other families of plants, especially Commely- nacee. The bamboos and the bamboo-panicums (Lasiacis) usually MORPHOLOGY OF THE VEGETATIVE ORGANS 107 have broad, comparatively short blades. In some cases the broad blades are unsymmetrical, one side being much wider than the other. These oblique blades are common in Olyree. In contrast to the broad surface mentioned above, the blades may be very narrow, when they are said to be filiform or capillary. Often the blades are rolled, thus appearing much narrower than they are when unrolled. Convolute blades are those in which one margin is rolled over the other. Involute blades are those in which both margins are rolled inward toward the center, the upper surface being inside. Revolute blades are those in which the margins are rolled outward, the lower surface being inside. Conduplicate blades are folded so that the upper surface of the two halves come in contact as in Poa Fendleriana and its allies. In common blue-grass one may observe all gradations between flat and completely conduplicate blades. Certain blades that appear to be rolled may be thickened into a slender terete or cylindrical form, the upper surface being repre- sented by a mere groove (forms of Festuca ovina, Andropogon Urbanianus). Petiole—In some leaves especially those of shade grasses mentioned above, there is a more or less well- marked petiole at the base of the blade. Examples: Orthoclada, Senites, Ichnanthus, many bamboos. 137. Nervation.—The vascular system of the grass blade consists of a strong main central axis, the midrib, and few to several smaller bundles called nerves, on each side parallel to the midrib. These nerves are continua- tions of corresponding nerves in the sheaths and they can usually be traced with the naked eye through the region of the collar. The anastomosing bundles, or cross-veins, are usually indistinguishable to the unaided eye. The broad blades of shade grasses (except Pharus and Lep- 108 A TEXT-BOOK OF GRASSES taspis) present arcuate nerves diverging at the base and converging at the apex, with numerous often conspicuous cross-veins, thus simulating the so-called netted-veined blades of dicotyledons. Besides the various genera already mentioned as having broad blades are the following which also present well-marked cross-veins: Olyrez, Centhotheca, Senites, Orthoclada, Pariana, many bamboos, and a few other genera. Pharus differs in having straight parallel lateral nerves that diverge from the midrib nearly throughout its length and join with a strong marginal nerve, instead of converging at the apex (Fig. 29). Leptaspis resembles Pharus, but Strepto- cheta is intermediate. 138. Auricles.—Some grasses bear, one on either side at the base of the blade, appendages known as auricles. These auricles are characteristic of the tribe Hordee and are found in certain species of other tribes. Wheat, rye and barley show prominent auricles. Rice and Festuca elatior and its allies are examples outside the Hordex. A very unusual development of the blade is shown in Phyllorachis sagittata Trim. and Spodiopogon sagittifolius Rendle. The base of the blade is extended into a long lobe on either side of the short petiole. ; 139. Roll-leaves.—In a preceding paragraph (Par. 136), casual mention was made of blades in which, by rolling in various ways, the exposed surface is reduced. This rolling of the blade is a xerophytic character and tends, by reduction of the evaporating surface, to lessen the loss of moisture. Such reduction of surface is charac- teristic of grasses of plains and desert regions, of sandy soil, especially along the seacoast, and of saline marshes. In some cases the blades are permanently rolled, in other cases they are flat under favorable conditions of atmos- pheric moisture but readily roll when the moisture MORPHOLOGY OF THE VEGETATIVE ORGANS’ 109 decreases. This rolling is a normal protective process and should not be confused with wilting. The blades of roll- leaves are marked on one or both surfaces with parallel channels and ridges, the latter being the nerves. The tissues of the ridges are firm and resistant while the cells of the channels are larger and thin-walled. These large cells, called bulliform cells, readily give off moisture. When the air is moist they remain turgescent, thus push- ing the ridges apart and holding the surface flat or at least partly open. As the air grows drier the bulliform cells become flaccid and the blade closes or rolls. To further aid the blades of xerophytic grasses to resist too great a loss of water, the stomata are usually arranged along the sides of the channels and are not exposed when the blade rolls. Examples of roll-leaves are forms of Festuca ovina and species of Stipa and Spartina. SCALES AND BRACTS 140. Scales are the reduced leaves found upon shoots below the foliage-leaves. They may be observed near the base of shoots of all perennial grasses, occupying gen- erally the portion below the surface of the soil and often a portion for a short distance above the soil. These scales, by overlapping above the growing point as a bud, protect the shoot as it pushes through the ground. Usually there is a gradual transition from scales to foliage-leaves, but sometimes the change is abrupt. In large grasses such as Gynerium sagittatum, the portion of the culm occupied by scales is much greater and may extend several feet above the surface of the soil. Bamboos, especially the vigorous shoots of the large species, furnish excellent examples of 110 A TEXT-BOOK OF GRASSES scales. These throw up a culm several inches in thickness, covered with large scales, and grow many feet in height before they develop foliage-branches. In_ perennial stemmed bamboos may be observed scales also upon the lower portion of branches. These scales often show transi- tions to foliage-leaves, the upper bearing rudimentary blades. , Scales are always produced upon rhizomes. Their chief function appears to be that of protection to the growing point as the rhizome is forced through the soil. The scales develop rapidly in the form of a bud at the end, overlapping and sharp-pointed. The terminal portion of some vigorous rhizomes is as hard as wood and as sharp as an awl. By the elongation of the internodes, the scales behind the growing point are separated and may become lacerated or otherwise lose their original shape. 141. Bracts are reduced leaves that are borne on shoots above the foliage-leaves. They may be discussed under two heads, those that are in or near the inflorescence, and those that are specially modified in the spikelet. The latter will be considered in a future paragraph dealing with the spikelet. Among flowering plants in general, bracts are usually found subtending each branch of the inflorescence down to the individual flower. In grasses these bracts are rarely present. In large panicles, as in some species of Bromus, the lower branches may be subtended by small bracts or there is at least a ridge representing a bract. Sheathing bracts are found in various genera, especially among Andropogonee, at the base of the entire inflorescence or of certain portions of it. In some grasses, the uppermost leaf below the inflorescence may have a much-reduced blade, for example many species of Poa, but such leaves MORPHOLOGY OF THE VEGETATIVE ORGANS 111 are usually classed with the foliage-leaves rather than with bracts. A peculiarly specialized bract is found at the base of the individual inflorescence of Job’s tears (Par. 203). It is urn-shaped, bony, and incloses the pistillate inflores- cence. At maturity it breaks away as a_bead-like 1-seeded fruit, CHAPTER XII MORPHOLOGY OF THE FLORAL ORGANS THE floral organs of phanerogams are known to be highly differentiated or specialized shoots, the receptacle representing a stem, and the stamens and pistils repre- senting greatly modified leaves. In the grasses the flowers are nearly always devoid of floral envelopes, the calyx and corolla being absent or represented only by the lodicules. The flower then is reduced to the essential organs, the stamens and pistil, the protection usually afforded by the floral envelopes being here afforded by bracts. THE INFLORESCENCE OR FLOWER-CLUSTER 142. The flowers of grasses are usually segregated upon distinct shoots that are easily distinguished from the foliage-shoots or the foliage portion of a shoot. These aggregations of flowers constitute the inflorescence. An inflorescence is always terminal upon the shoot, and commonly these shoots are the main foliage-shoots of the plant, as in wheat, blue-grass, timothy and sorghum. In addition to the inflorescence terminating the main culm and leafy branches, others may arise from the axils of the leaves. Such lateral inflorescences are, of course, terminal upon lateral branches, but since such branches bear no foliage-leaves the inflorescences are said to be lateral or axillary. In some grasses such as bamboos, bamboo- panicums, and less commonly in herbaceous genera, the (112) MORPHOLOGY OF THE FLORAL ORGANS 113 culms produce foliage-branches some or all of which may end in an inflorescence. The unit of the inflorescence is the spikelet, which consists of one or more flowers with the subtending floral bracts. The common forms of inflorescence are the spike, the raceme and the panicle. 143. Kinds of inflorescence——The spike—tThe spike- lets are sessile along an elongated axis. Familiar examples of this form are the members of the tribe Horde, as wheat and rye (Figs. 57-62). The raceme-—tThe spikelets are pediceled and borne along an elongated axis. Simple forms of meadow fescue and sheep’s fescue show racemes. The individual inflo- rescence of Paspalum is apparently a spike, but really a spike-like raceme. The panicle—The spikelets are pediceled and the inflorescence is repeatedly branched. The oat- and blue- grass are familiar examples (Fig. 54). Mized inflorescences——True spikes, except in the Hor- dez, are rare, as is also the simple raceme. An inflores-— cence that is apparently a spike often shows that the spikelets are not sessile but more or less pediceled. Such an inflorescence is properly a spike-like raceme. Similarly a panicle may be so contracted that the pedicels and short branches are hidden and the inflorescence appears to be a spike, but in precise language should be called a spike- like panicle (Fig. 38). The component parts of the inflorescences of the genera Pas- palum and Syntherisma (e.g., crab-grass) are spike-like racemes. The so-called spikes or heads of timothy and canary-grass are spike- like panicles. In the genus Andropogon what appears to be a spike consists of a jointed axis, each joint bearing a pair of spikelets, one sessile H 114 A TEXT-BOOK OF GRASSES the other pediccled. The inflorescence is therefore generally re- ferred to as a raceme or as composed of racemes (Fig. 16). Simple racemes with elongated pedicels are not common. - Simple panicles in which the spikelets are racemosely arranged above and more or less paniculate below are frequent. The meadow fescue and other fescue grasses usually bear this kind of an inflor- escence. Compound inflorescence—This term has received no very precise application. It is usually applied to a large inflorescence made up of numerous smaller inflorescences, especially if the latter have their distinctness emphasized by sheathing bracts as in Cymbopogon Nardus and many other Andropogonez. 144. Unisexual inflorescences.—The spikelets that make up an inflorescence are usually alike, and consist of perfect flowers. But sometimes the spikelets are uni- sexual, the male and female spikelets being in distinct and usually dissimilar inflorescences. There are a few dicecious genera such as Spinifex, Bulbilis, Scleropogon, Gynerium and Jouvea. In these the inflorescence of the staminate plants is very different in appearance from that of the pistillate plants. Sometimes the difference is so great that the different forms might easily be considered by the casual observer to belong to distinct species or even to distinct genera. There are cases where the two forms have been described by botanists as belonging to distinct genera. In the common buffalo-grass of the plains the staminate inflorescence consists of 1 to 3 one- sided spikes raised on a peduncle a few inches long (Fig. 48), while the pistillate inflorescence is hidden among the foliage close to the surface of the ground (Fig. 49). Some- times (e.g. Distichlis) the staminate and pistillate inflores- cences are similar though not alike (Fig. 52). MORPHOLOGY OF THE FLORAL ORGANS 115 Fournier described the genus Jouvea from pistillate specimens. Staminate plants of the same species (J. straminea Fourn.) he re- ferred to Brizopyrum. The staminate specimens of Jowvea pilosa (Presl) Scribn. were first described under Brizopyrum. The stam- inate plants of Bulbilis dactyloides were first described under Sesleria. 145. Moneecious genera, in which the staminate and pistillate flowers are borne in distinct and dissimilar por- tions of the inflorescence, are not common. These include Tripsacum, Olyra, Zizania, and a few related genera. In Tripsacum the staminate flowers occupy the terminal portion of the spikes. In Olyra and Zizania (Fig. 31) the staminate flowers are in the lower part of a panicle. In a very few genera, the staminate and pistillate inflores- cences occupy different parts of the same plant. Zea and Euchlena belong to this group. The tassel of the corn is the staminate inflorescence; the ear is the pistillate inflorescence. Not a few grasses, as many Andropogonee, produce unisexual spikelets that are interspersed with perfect spikelets, usually in some definite relation, but all in the same inflorescence (Fig. 16). 146. The axis of inflorescence—The usual form is slender and cylindrical, but it may take on a variety of other shapes. In the spike of Horde, the axis is somewhat zig-zag by the alternate insertion of the large spikelets at the nodes. The internodes or joints are flattened or con- cave toward the spikelet and convex on the opposite side. In many Hordeze the axis disarticulates at the nodes at maturity. Such disarticulation often occurs also in other groups, especially among the Andropogonex. The axis is sometimes greatly thickened and the surface hollowed out, the spikelets fitting into the cavities. Such is the case in Tripsacum, Manisuris and several other genera of these tribes, and also in Stenotaphrum (Fig. 28). In the 116 A TEXT-BOOK OF GRASSES latter, however, the inflorescence is really branched, shortened branchlets with 2 spikelets being borne in each of the cavities of the axis. Sometimes, as in Tripsacum and Euchlena (Fig. 11), the axis disarticulates and the 1-seeded joints become hard bead-like fruits. The cob of an ear of corn is a greatly thickened axis of inflorescence, the structure of which is discussed in Par. 202. The spikes and spike-like racemes of Chloridez and of many Panicee are I-sided. Here the axis has developed so unsymmetrically that the 2 rows of spikelets have been forced to one side. The axis may appear thin and much flattened as in many species of Paspalum (e. g., P. repens and P. stellatum) or somewhat triangular with a row of spikelets on each of 2 sides, as in crab-grass. The name rachis is usually applied to the axis of spikes, and spike-like racemes or panicles, or to the axis of any contracted inflorescence or portion of an inflorescence. 147. Branching of panicles—The main branches of a panicle are known as the primary branches. Those which arise from these are secondary branches and this name may be applied to branches of the third or higher order. The ultimate branches or branchlets which are the stalks of the individual spikelets are the pedicels and will be considered when the structure of the spikelet is discussed. — The primary branches of a panicle often appear to be verticillate or at least more than one from a node. It will be observed however that in many cases there is 1 primary branch and that the others are secondary branches developed at the base of a primary branch. If the verticils are composed of primary branches the aggregation is due to the failure of the internodes to elongate. If the several branches originating at one node all stand at one side of the main axis and those at the next node stand on the MORPHOLOGY OF THE FLORAL ORGANS 117 opposite side, it indicates that there is 1 primary branch and the others are basal secondary or even tertiary branches. Blue-grass and cultivated oat illustrate this. The former normally has 5 branches at the lower node of the inflorescence, one of which, the longer central one, is a primary branch, the others being branches of higher order. 148. Motor organs—In the axils of the primary branches of open or spreading panicles, and often in the axils of some of the secondary branches, are to be found swellings or cushions of tissue. These are motor organs whose function is to spread the branches of the panicle at the proper time. This opening takes place when the spikelets on the branch have reached the stage of anthesis, and progresses from above downward, the branches at the base being the last to develop and open. The move- ment is brought about by an increase in size due to tur- gidity thereby spreading the branch. Usually these motor organs act only during anthesis and then harden, but some- times by losing their turgidity they later bring about a contraction of the panicle, as in Dactylis glomerata (Fig. 53) and Agrostis alba. Occasionally the ultimate branches of the inflorescence do not end in a spikelet. Such branches are known as sterile branches. The bristles conspicuous in the spike- like panicles of Chetochloa are sterile branchlets. THE SPIKELET 149. The spikelets are the units of the inflorescence and are borne upon its ultimate branches, the stalks being called the pedicels. The spikelet consists of a short axis bearing 1 or more flowers in the axils of 2-ranked imbri- cated bracts. As an example of a typical spikelet, that 118 A TEXT-BOOK OF GRASSES of Eragrostis cilianensis (EH. megastachya) may be consid- ered (Fig. 51). The lower pair of bracts are empty and are called glumes. The lower is the first glume; the upper the second glume. The midnerve is the keel. The bracts above the glumes are regularly arranged on a slender axis or rachilla, alternately in 2 ranks. These are called lemmas. In the axil of each lemma, except 1 or more of the reduced uppermost, there is a flower, and between the flower and the axis a second smaller bract called the palea. The lemmas are also keeled and have a pair of lateral nerves. The palea is 2-keeled, and is inclosed within the margins of the lemma. The lemma and palea together with the inclosed sexual organs are called the floret. The spikelet may be interpreted as a specialized branch, bearing a series of bracts, or modified leaves, the lower pair (glumes) being empty, the others (lemmas) bearing a much specialized branchlet (the flower) in the axil, the palea being the prophyllum. The terminology here adopted differs somewhat from that in common use in early works on agrostology. The terms with which the student is more likely to come in contact are: For glume, the terms empty glume and empty scale; for lemma, the terms flowering glume, flowering scale and lower palea or palet; for palea the altered spelling palet. The objection to the term scale is that this name is | applied only to modified leaves on a shoot below the foliage-leaves. The modified leaves of the spikelet are, then, to be included under the general designation, bracts. It seems desirable, however, that special terms be adopted for these parts as they are so often used. In this the writer is following the leading contemporary works on plant morphology. Again, for the sake of brevity and precision, there is a distinct advantage in using separate terms for the bracts containing flowers, and for the empty pair at the base of the spikelet. Morphologically the glumes and lemmas are equivalent, and hence the terms empty glume and flowering glume are entirely proper. But the constant difference in relation and function justifies the MORPHOLOGY OF THE FLORAL ORGANS 119 greater distinction of the terms employed for them and the re- duction of these terms to a single word. The term lemma was first used by C. V. Piper.* Linnzus called the glumes the calyx, and the lemma and palea the corolla, to codrdinate the terms with those used in other groups of plants. The individual glumes, lemmas and paleas he called valves. He speaks of the calyx of Panicum as being 1-flowered and 3-valved; of the corolla as being 2-valved; the calyx of Phleum is 1-flowered and 2-valved; the calyx of Poa is 2-valved but contains many flowers; the calyx of Uniola is 6-valved (referring to the several empty bracts at the base of the spikelet) and contains many flowers. According to Kunth, the spikelet of Sporobolus consists of 2 glumes and 2 paleas; Panicum of 2 glumes, a lower masculine or neutral flower with 1 or 2 paleas and an upper perfect flower with 2 paleas. Gray (Man., ed. 5) uses the same terminology as Kunth. Watson (Gray, Man., ed. 6) uses the terms empty glumes and flowering glumes. Bentham (Benth. & Hook. Gen. Pl.) calls all the bracts of the spikelet glumes and applies the term palea properly. If the glume incloses a flower it is a flowering glume, otherwise an empty glume. Hence the spikelet of Sporobolus is said to have 3 glumes, 2 empty and 1 flowering; of Panicum to have 4 glumes, the fourth and some- times the third a flowering glume. Stapf. (Fl. Cap.) uses the terms glumes; valves for lemmas, and pales for paleas. The spikelet described above may be considered typical and represents the usual structure in the tribe Festucee. There are many departures from this type form, however. The glumes may be 1 or none; the flowers in the spikelet may be reduced to 1 or to 1 perfect flower with additional staminate or sterile flowers above or below; the glumes or lemmas may be modified in various ways; or the whole spikelet may be sterile. These modi- *Contr. U.S. Nat. Herb. 10: 8. March 30, 1906. Science, N.S. 23: 790. May 18, 1906. 120 A TEXT-BOOK OF GRASSES fications will be discussed in detail later. Unisexual spikelets have been mentioned under Par. 144. 150. Sterile spikelets—Sterile spikelets are those which differ from the spikelets with which they are associated, in lacking sexual organs. For convenience the term is sometimes made to include spikelets that con- tain stamens, when such spikelets are the equivalents of the sterile ones. In Andropogon the spikelets are in pairs, a sessile fertile one and a second pediceled one, which in different species may be staminate, empty or reduced to the pedicel (Fig. 16). This second or pediceled spike- let is generally referred to as the sterile spikelet. In some genera in other tribes sterile spikelets occur, usually in a definite relation to the fertile ones. These sterile spike- lets are prominent in Achyrodes and Cynosurus. In Hordeum the spikelets are in clusters of 3, but usually the 2 lateral are sterile. In Phalaris paradoza the spike- lets are in groups of 7 of which 6 are sterile. Sterile spike- lets (when lacking stamens) are sometimes called neuter or neutral spikelets. Staminate spikelets, except those referred to above which have a definite position and are the equivalents of neuter spikelets, should not be called sterile spikelets. 151. The pedicel is the stalk of the individual spikelet and represents the ultimate branching of the inflorescence. If the pedicel is so short that it is not evident the spike- let is said to be sessile. On the other hand the pedicels may be elongated and extremely slender as in Orthoclada. Sometimes they are slender and nodding, so that the spikelets vibrate or tremble in the breeze, as in Briza media, the quaking-grass. The pedicel may be jointed below the spikelet, in which case the spikelet disarticu- lates from the pedicel at maturity. This is true of most of MORPHOLOGY OF THE FLORAL ORGANS 121 tribe Panicee. In the series Poxoidee the pedicel is usually not jointed below the spikelet but the rachilla may be articulated below the first lemma, so that at maturity the upper part of the spikelet falls away leaving the glumes. There are exceptions in both groups. In many species of Eragrostis the rachilla remains attached to the pedicel and the lemmas fall away. The pedicel is sometimes differently developed in the same inflorescence, as in many Andropogonez, where the spikelets are in pairs, one being sessile and fertile, the other pediceled and bearing a staminate spikelet or only a bract which may represent a glume, or the spikelet may be aborted, the pedicel persisting as a naked stalk. The pedicel may be grown fast to the axis as in Rytilix and Manisuris. 152. The glumes are the 2 empty bracts at the base of the spikelet and are called respectively the first and second glume. They usually differ in shape, nervation or texture or in other particulars from the lemmas above them. Frequently the first glume is smaller than the second and often has fewer nerves. Sometimes this reduction goes so far that the first glume is only a vestige or it may be altogether wanting. Syntherisma shows various stages in the elimination of the first glume, and in Paspalum the first glume is generally absent or repre- sented by a slight ridge. However there are species of Paspalum in which the first glume may be present or absent in the same raceme (P. distichum, Paspalum § Dimorphostachys). The first glume in Eriochloa is usually represented by a cup-shaped ridge below the normally shaped second glume, but is present in certain species. Both glumes are absent in a few genera, such as Reimaro- chloa and Homalocenchrus. 122 A TEXT-BOOK OF GRASSES The student should take careful note of the theoretical relations of the parts of the spikelet, since it is a knowledge of these relations that enables one to assign a morphological status to an absent organ. The glumes and lemmas are morphologically equivalent, namely bracts. But in the great majority of species of grasses the lower 2 bracts of the spikelet are empty and the others above contain flowers. By definition the lower pair are called glumes and those above are called lemmas. The glumes are nearly always differentiated structu- rally from the lemmas. The theory of the evolution of organisms teaches us to trace the development, progressively or retrogressively, of organs through groups of allied species. Such an examination will usually enable us to interpret correctly the morphology of the organs. For example, we wish to know the morphology of the spikelet of Reimarochloa and Homalocenchrus. In the former we have a spikelet consisting of 1 empty bract and 1 flowering bract. How is this to be interpreted? In the first place we are confident that the genus belongs to the large tribe Panicez and that it is closely allied to Paspalum and Panicum. The typical spikelet of the Panicez consists of 4 bracts, the upper- most of which contains a perfect flower. This bract, by definition a fertile lemma, is distinctly different from those below. The first and second bracts are empty and by definition are glumes. The third is by definition also a lemma even though it contains no flower. An examination of the spikelets of various genera shows that there are all gradations between species in which the lower lemma, usually called the sterile lemma, contains a perfect flower (Isachne) to those which contain stamens, or only a palea, and finally to those which are empty. This, of course, confirms the statement that the third bract is a lemma. No transitions are found between the glumes and the lemma. But we do find a tendency on the part of the glumes to retrogress in size. The first glume is usually smaller than the second, and the retrogression can easily be traced through its slight develop- ment in Syntherisma and Panicum to its disappearance in Paspalum. Similarly the second glume shows a tendency to disappear, cul- minating in its absence in Reimarochloa. Furthermore, there is no tendency for the second glume to disappear before the first. From the above we conclude that the single empty bract below the fertile lemma in Reimarochloa is the sterile lemma, that is, it is homologous with the third bract or sterile lemma of the typical spikelet of the tribe. MORPHOLOGY OF THE FLORAL ORGANS 123 We may also conclude that the 2 organs inclosing the flower of Homalocenchrus are lemma and palea and that the 2 glumes are absent, since in Oryza, a closely allied genus, the glumes are present, though small. The glumes are sometimes awned, but less frequently so than are the lemmas. They are variously modified and distorted in a few genera, the first glumes of a group of spikelets together forming a sort of involucre around the group (Anthephora), thickened like a bird’s head (Lopho- lepis), globose and pitted (Rytilix). The large second glume is covered with hooks in Nazia so that the group of spikelets becomes a bur. In Alopecurus the glumes are connate, that is, grown together along the edges to form a cup (Fig. 39). 153. Anomalous glumes.—The ainies of some genera of Hordee show certain anomalies. In Lolium and in a few allied genera the spikelets are sessile on a flattened rachis but stand edgewise to this instead of crosswise as is usual in other genera (Fig. 57). But one glume (the second) is present and this on the outer side of the spike- let. It is longer and larger than the lemmas, sometimes longer than the spikelet, and looks like a subtending bract. In the terminal spikelet of the spike, however, both glumes are developed. In Sitanion and some species of allied genera the glumes are reduced to subulate awns, these forming a sort of involucre to the groups of spike- lets. In certain species of Elymus (e.g., EH. virginicus L.) the glumes of the lateral spikelets stand in pairs in front of the spikelets. Hochstetter states that the glumes of Hordeum and many species of Elymus are single but cleft into 2 parts. Schenck thinks that they are sterile spikelets. (For full discussion, see Bot. Jahrb. Engler 40:97. 1907.) 124 A TEXT-BOOK OF GRASSES 154. The lemmas are the bracts of the spikelet above the glumes. They ordinarily subtend flowers but some- times are empty. The lemmas vary from 1 to many (as many as 50 in Eragrostis) and except in Streptocheta are in 2 ranks upon the rachilla. As is usually the case with bracts, the lemma represents the leaf-base, the blade not being developed. Streptocheta is an anomalous Brazilian genus in which the lemmas are spirally arranged. In the more primitive forms of grasses, the lemmas are usually bract-like in appearance and in a general way resemble the glumes, being greenish, keeled and nerved. In more modified forms such as Andropogonee, the lemmas are often thin and delicate, being entirely inclosed by the enlarged and indurated glumes. On the other hand, the lemma may be hardened, as in most Panicez, where the lemma of the fertile floret is hard, usually smooth and nerveless. Modification is carried to a greater extent in the lemma than in any other organ of the grass plant. For this reason the form of the lemma is of great impor- tance in classification, its shape, texture and nerving being uniform within definite limits in any given genus. In those genera, such as Andropogon and its relatives, Hilaria, Anthephora and the like, in which the glumes are enlarged, indurated or otherwise specialized, the lemmas are found to be thin or small or otherwise to show but little modification. In grasses having unspecialized or but slightly modi- fied glumes, as in most of the genera, the lemmas are usually strongly characteristic. The lemma, whether bearing a fertile flower or empty, as in the lower lemma in most species of Paniceze, or modified into a cluster of MORPHOLOGY OF THE FLORAL ORGANS “125 awns, as in some species of Chloridez, is to be recognized by its position on the rachilla. In canary-grass (Phalaris canariensis L.) there are 2 minute bracts at the base of the fertile lemma. These are greatly reduced lemmas. The indurated lemma of Stipa and Aristida is peculiar in that it assumes a cylindrical form and extends downward into a hard, sharp-pointed callus (Figs. 35, 36). At maturity the fruits, by means of this sharp point and by the hygroscopic awns at the apex, are able to bury themselves in the soil. Certain genera of Andropogonee (Hetero- pogon, Chrysopogon) produce fruits similar in general appearance to those of Stipa, but in the former the fruit is developed from a spikelet instead of from a floret. In Heteropogon and other genera of Andropogonez with stout awns, the first glume is indurated, cylindrical and sharp-pointed at base as in the lemma in Stipa. Within this are the second glume, the sterile lemma and the fertile lemma, all thin and hyaline, the latter bearing the long stout awn. 155. Sterile florets and sterile lemmas.—Sterile florets are those which differ from the perfect florets of the spike- let in which they are found in lacking pistils. They may also lack stamens, and consist of a lemma and palea, or the palea also may be lacking. The lemma of such a floret is called a sterile lemma. If a lower floret lacks stamens, then the lemma is the same as the third empty glume of some authors, when they refer to bracts above the first pair. In many genera of the series Poaoideze the upper florets are reduced to sterile florets. In Melica there may be 2 or 3 sterile lemmas successively convolute one within another. In most of the genera of Panicoidez there is a sterile floret below a terminal perfect one. The sterile floret of Panicum and its allies has been mentioned 126 A TEXT-BOOK OF GRASSES before (Par. 152). The sterile lemma of Andropogonee, also below the perfect floret as in Panicexe, is membrana- ceous, thinner than the glumes, often very delicate. In the tribe Phalaridez, there are usually 2 sterile florets at the base of the terminal fertile floret (Fig. 34). These lateral florets may be empty (Phalaris, Anthoxanthum) or staminate (Savastana). 156. The awns are bristle-like continuations of the nerves of the glumes or lemmas. Awns involve vascular tissue while hairs of various kinds (trichomes) involve only epidermal tissue. The commonest position for the awn is terminal as in Festuca, where the midnerve is extended as a bristle. Often the apex of the lemma is cleft and the awn arises from between the lobes or teeth. Occasionally the 2 teeth thus formed are also awned. Sometimes the lateral nerves of the lemma extend into teeth or awns (Tridens). In the cases mentioned, the central awn is terminal. Sometimes the awn arises below the apex of the lemma even nearly at the base, in which case it is said to be dorsal. When the awn is dorsal, the lemma shows no midnerve above the point of attachment of the awn or rather above the point where the midnerve separates from the tissue of the lemmas, thus forming an awn (Fig. 45). The awns of Aristida (Fig. 35) are usually trifid, with divergent often much-elongated branches (as much as 4 inches long in a South American species). In Pappophorum the lemma is divided at the summit into many awns. In other genera the awns are hooked, or bent, or variously divided, sometimes smooth, but usually scabrous, some- times plumose. In several genera the awn is jointed at the base and deciduous, as in Oryzopsis, Nassella, Pipto- cheetium. MORPHOLOGY OF THE FLORAL ORGANS 127 Morphologically the awn is thought to represent the blade, and the lemma the sheath of a primary leaf. If the awn is dorsal the free portion of the lemma above the insertion of the awn probably represents the ligule. (See Domin, Ann. Jard. Bot. Buitenzorg 24:200. 1910.) 157. Twisted awns.—Not infrequently the awns are spirally twisted. This torsion is well shown in the large awns of certain species of Stipa, such as the porcupine- grass of the prairies (S. spartea Trin.). The awns are several inches long, stout at base but tapering to a fine point (Fig. 36). The awn at first is straight and untwisted, but at maturity it bends at 2 points and becomes closely spirally twisted up to the second bend. The torsion is very sensitive to atmospheric moisture so that the awn becomes less twisted or almost straight in moist air and twists tightly again in dry air. Twisted awns are found especially in Andropogonee (Fig. 16), Avenes (Fig. 44), and Stipa. 158. The palea is the bract standing between the flower and the rachilla. It is usually 2-nerved or 2- keeled with the space between the nerves concave and with the margins bent forward about the flower. It is homologous with the prophyllum which it resembles in structure. The palea is usually embraced by the lemma at the margins, or sometimes entirely inclosed as in Stipa and Aristida, although it may project more or less at the apex. Though the palea is usually 2-nerved, it is appar- ently 1-nerved in a few genera because the 2 nerves are so close together (e.g., Cinna). So-called 1-nerved paleas occur only in 1-flowered spikelets. The apex of the palea is usually rounded or notched but may be toothed, the teeth being rarely awned. The keels are usually smooth or scabrous but may be ciliate (Eragrostis), winged (Pleu- 128 A TEXT-BOOK OF GRASSES ropogon), or the margins may be greatly enlarged (Ixo- phorus). The palea is reduced to a nerveless scale or may be obsolete in Agrostis and in species of Andropogon. The palea usually falls from the rachilla together with the lemma but may be persistent upon the axis (e. g., Eragrostis, Fig. 51). 159. The lodicules are small organs found at the base of the floret, outside the stamens. They are usually 2 in number, standing in front of the lemma, close together. A third lodicule is present in a few genera and is placed in front of the palea. In the anomalous bamboo genus Ochlandra there are several lodicules. The function of the lodicules is to open the floret at anthesis. They become turgid and thus spread the lemma and palea apart, later collapsing and allowing the floret to close by its own elasticity. The lodicules are interpreted by some to be homologous with the divisions of a perianth of which only 2 divisions have usually persisted. 160. The stamen consists of a delicate filiform fila- ment and a 2-celled anther, opening by longitudinal slits. The anthers are basifixed but so deeply sagittate, as to appear versatile. There are usually 3 stamens, 1 standing in front of the lemma and 1 opposite each edge of the palea. Sometimes there is a second whorl inside of the first and alternating with it, making 6 stamens (most bamboos, many Oryzew). There are various departures from these numbers. There may be only 2 (Diarrhena), or only 1 (Cinna), rarely 4 in 2 whorls, and in certain anomalous genera more than 6 (Pariana, Luziola, Ochlandra). The filaments are more or less connate in a few bamboos and in Streptocheta. From the standpoint of evolution, the species with 6 stamens in 2 whorls probably represent a more primitive form as this structure MORPHOLOGY OF THE FLORAL ORGANS 129 would tend to show relationship with the lilies. The species with 1 and 2 stamens evidently show a reduction from the usual 3-stamened type by the abortion of 1 or more of its members. 161. The pistil is single, with a 1-celled ovary, 2 styles and 2 stigmas. Occasionally there are 3 styles (Strepto- cheta, some bamboos), or only 1 (Nardus). There is apparently only 1 also in corn (the ‘‘silk’’) but this arises from the union of 2. When there are 2 styles or 2 sessile stigmas they arise not from the apex of the ovary but from the sides near the apex. Sometimes there is a single style that divides into 2 branches. The styles of corn are unusually long and slender thus raising the stigmas out of the large bracts or husks surrounding the ear. The stigmas usually consist of papillate or plumose continua- tions of the styles. The ovary contains a single ovule grown to the side of the ovary without a funiculus, the micropyle turned downward. In Streptocheta and Strep- togyne the long spirally twisted styles and stigmas of adjacent spikelets become interlaced at maturity. According to Hackel and others, the pistil is 1-carpeled; according to Walker, it is made up of 3 carpels (Walker, “On the Structure of the Pistils of Some Grasses.’’ Univ. Nebr. Studies 6: No. 3. 1906.) 162. The fruit is usually a caryopsis, the seed being adherent to the pericarp. The seed-coat is poorly devel- oped and the pericarp acts as a seed-coat. The caryopsis is sometimes more or less united with the palea, rarely also with the lemma. The caryopsis is, however, often inclosed within the lemma and palea without being adher- ent to them. As in flowering plants in general the fruit in the restricted sense is the ripened ovary and its contents. In a wider sense the fruit is the ripened ovary together with the adjacent parts which may aid in I 130 A TEXT-BOOK OF GRASSES protection, germination or dispersal. In the present discussion the term fruit is used in both senses. The fruit of Panicum and allied genera consists of the hard, tightly closed fertile lemma and palea within which is the caryopsis (Fig. 21). Not infrequently the awn of the lemma is involved in the fruit and performs an important function in dispersal or in connection with germination. This is the case with Stipa (Fig. 36), Aristida (Fig. 35), Heteropogen and many Avenez. The fruit may include the surrounding sterile branchlets forming a bur, as in Cenchrus (Fig. 27); a greatly har- dened inclosing bract, as in Coix (Fig. 12); the joints of the rachis in which the spikelet is partially inclosed, as in Tripsacum; or a combination of rachis joint and long- awned sterile spikelets, as in Sitanion and Hordeum. Rarely the ovary ripens into some form other than a caryopsis. In a few genera such as Sporobolus and EHleu- sine, it becomes an utricle, the pericarp being thin and not grown to the seed. In many species of Sporobolus, for example S. airoides Torr. and S. indicus (L.) R. Br., the pericarp tends to split vertically into 2 valves, thus being dehiscent. The pericarp of Eleusine breaks away irregu- larly. The fruit becomes a nut or a berry in certain bamboos. 163. The seed consists of an embryo at the base on one side and of endosperm occupying the remaining por- tion. If the surface of a caryopsis is examined, the posi- tion of the embryo is outlined as a depressed usually oval area at the base on the front side, that is, on the side facing the lemma. On the opposite side, next the palea, is the mark called the hilum, which indicates the place where the seed was attached to the wall of the ovary (pericarp). The hilum may be elongated if the seed is MORPHOLOGY OF THE FLORAL ORGANS 131 attached for a considerable distance, or may be puncti- form, and is characteristic in shape for some genera. There is often a furrow on this posterior side of the caryopsis in which will be found the hilum. Since the palea is often grown to the caryopsis this must be removed when search- ing for the hilum. 164. The embryo is straight or nearly so, the plumule directed upward and the young root downward. The corn grain illustrates the general features of all grass embryos. An important organ is the scutellum which is attached to the embryo at the middle and enfolds it, lying against the endosperm on its outer surface. This organ is thought to represent the first leaf or cotyledon. Its function is to absorb the nourishment from the stored food during germination. In large embryos like the corn there may be observed on the sides of the epicotyl, or first joint above the attachment of the scutellum, the begin- nings of lateral or secondary roots. In other genera the rudimentary secondary roots usually appear on the hypocotyl. 165. The endosperm consists mainly of starch, although there is a considerable amount of oil, which, however, is mainly in the embryo. On the outside within the epidermis is a layer of cells containing aleurone, rich in protein. The stored food is also called albumen by some authors. The endosperm is hard and corneous or mealy according to the density of the starch-contain- ing cells. 166. The rachilla is the axis of the spikelet. It may be jointed to the pedicel below the glumes (usual in Pani- coides), or jointed above the glumes (usual in Poa- oideze). It may be continuous (Eragrostis, Fig. 51) or articulated between the florets at maturity (Festuca). 132 A TEXT-BOOK OF GRASSES In genera with many-flowered spikelets the rachilla is of course elongated, while in 1-flowered spikelets it is reduced so that the floret seems to be terminal. It often extends beyond the insertion of the upper floret in many-flowered spikelets but is usually hidden by the upper lemmas. In 1-flowered spikelets the rachilla may extend beyond the base of the floret. It then appears as a slender sometimes “plumose bristle or stalk pressed against the palea. This extension of the rachilla sometimes bears a rudimentary second floret. The first internode of the rachilla above the glumes is sometimes elongated, forming a stipe to the floret. This stipe may be developed into a sharp-pointed callus, which at maturity aids in seed-dispersal (Stipa, Aristida). Usually the internodes of the rachilla between the florets are short, the florets being closely imbricated; but, occasionally, they are elongated, the florets being rather distant, as in Senites. A peculiar jointing of the rachilla is to be observed in Festuca subuliflora Scribn. in which there is an articulation midway between the distant florets. This is probably due to ‘a downward elongation of the callus, surrounding and becoming grown to the rachilla, which has likewise become elongated so that the joint is still at the base of the callus.” * * Piper, Contr. U.S. Nat. Herb. 10:36. 1906. CHAPTER XIII ECOLOGY Ecouoey is that branch of botany which treats of the relation of plants to their environment. It is often con- sidered to be a branch of physiology since it is a study of the response to stimuli. Plants are acted upon by exter- nal factors, either physical or biological. The response to these forces determines the plant’s adaptation to its environment. The more important ways in which grasses are influenced by environment will be briefly discussed. SEED DISPERSAL 167. The seeds of grasses are for the most part adapted to dispersal by means of the wind. Some kinds are so small that they are readily transported in this manner without any special adaptation. The fruit by itself (Eragrostis) or inclosed in the lemma and palea (Poa) is easily blown about by air currents. In Panicum and its allies the whole spikelet falls away by disarticula- ting below the glumes. Among the Andropogonee the axis of the spike usually disarticulates between the pairs of spikelets and the resulting joints are sufficiently small to allow of their being easily transported by the wind. 168. Dispersal by wind.—But the fruit is not infre- quently modified in such manner as to make wind dis- persal more effective. A common adaptation is the devel- opment of silky hairs on some part of the fruit. Such (133) 134 A TEXT-BOOK OF GRASSES hairs are found on the lemmas in Arundo, on the rachilla joints in Phragmites, on the whole spikelet in Saccharum (Fig. 14), on the awns in Stipa pennata L. of Europe and S. speciosa Trin. & Rupr. of California, on the long pedi- cels of S. elegantissima Labill. of Australia. Awns and bristles often aid dispersal by increasing the surface. Clus- ters of spikelets, with their surrounding involucre of bris- tles, fall away from the rachis, the bristles catching air currents. Long-awned species of Horde, with disarticu- lating rachis, are adapted to wind dispersal. Sitanion and Hordeum are good examples of this. The joints of Sitan- ion, with their numerous long awns spreading in all direc- tions, are sent whirling across the open grassland in the western states. In many species of Aristida (Fig. 35) the 3 awns spread horizontally or are somewhat reflexed. On the Great Plains it is common to see, at the proper season, the fruits of these grasses being hurled along by the high winds, the sharp-pointed callus to the front ready to catch in the wool or hair of animals. From such fruits it is an - easy transition to wing-fruits, in which the increased sur- face is furnished by wings, appendages or sterile parts. The inflated lemma of Briza, the winged crests on the lemmas of Phalaris, the group of sterile spikelets of Phalaris paradoxa, all aid in dispersal. In some grasses the whole inflorescence breaks away and becomes a “tumble-weed.”’ The panicles of Panicum capillare L., Agrostis hiemalis (Walt.) B. 8. P., Chloris verticillata Nutt. and Eragrostis pectinacea (Michx.) Nees, are familiar exam- ples. At maturity the panicles separate from the plant and roll over the surface of the ground before the wind, the widely spreading branches making the whole very light. The small fruits are dropped here and there as the panicle travels. The inflorescence of Schedonnardus panic- ECOLOGY 135 ulatus (Nutt.) Trel., a common grass in Texas, consists of several slender distant spikes arranged along a slender axis. After flowering, the central axis greatly elongates becoming at the same time somewhat spirally coiled. The lateral spikes also elongate. There results a loose cylin- drical skeleton that can be easily rolled along by the wind after it disarticulates from the parent plant. An indirect method of adaptation for wind dispersal is illustrated by the fruits of Eleusine indica (L.) Gaertn. and Sporobolus indicus (L.) R. Br. The pericarp of these, when wet, develops a mucilage by which the seeds are enabled to stick to leaves or other objects that may be blown about by the wind. In so far as they are able to stick to birds or other animals they are adapted also to this method of dispersal. 169. Dispersal by animals—Some grasses are adapted to dispersal by the aid of animals. The species of Cen- chrus (Fig. 27) produce burs made up of a group of con- nate branchlets armed with retrorsely barbed spines. The bur-like spikelet of Nazia produces hooks on the second glume. The callus of the fruits of Aristida (Fig. 35), Stipa (Fig. 36), Heteropogon, Chrysopogon and other needle-fruits of this kind, is sharp-pointed and armed with retrorse hairs. Such fruits readily bore into the coats of animals. The fruits of certain Hordes, with disarticulating rachises, have been mentioned above under adaptations for wind dispersal Usually in these fruits, the point of the rachis-joint is sharp and the awns are antrorsely scabrous (the teeth pointing forward). They thus are adapted to working their way into the coats of animals. In Panicum glutinosum of the American tropics the spikelets are viscid and readily attach them- selves to a passing body. 136 A TEXT-BOOK OF GRASSES GERMINATION 170. The situation of the embryo in the grass seed is such that by the enlargement and growth of the organs the plumule and root at once emerge in opposite direc- tions. The seed remains in position, which is usually upon the surface of the ground. The primary root at first elongates but soon secondary roots appear which in a short time exceed the primary. The plumule pushes up somewhat later. The first leaf of the plumule acts as a protecting sheath and never develops into a foliage leaf. If the seed is below the surface of the soil this sheath, closed at the apex, elongates until the surface is reached, when the tip breaks and the bud pushes through. In many embryos there is a small scale-like organ (epiblast) at the base of the plumule opposite the scutellum. This is thought by some to represent a leaf, in which case the scutellum is the first leaf or cotyledon, and the pro- tecting sheath of the plumule is the third leaf. 171. The germination of the maize is described at length by Collins. The protecting sheath he calls the coleoptyle. Between the coleoptyle and the seed is a more or less elongated axis to which the name mesocoty] is given. This portion is called by Hackel and others the epicotyl on the supposition that it is an internode above the cotyledon or scutellum. Collins and others consider the scutellum, epiblast and coleoptyle to be all parts of a highly specialized cotyledon. Collins also describes the germination of Hopi and Navajo varieties of maize in which the mesocotyl elongates greatly, reaching the enormous length of 25 or even 30 cm. The plumule is thus able to reach the surface from a corresponding depth. Such varieties are adapted to dry regions. The usual ECOLOGY 137 varieties of maize are unable to force the mesocotyl to a length greater than 10 em. (Collins, Journ. Agr. Res. 1: 293. 1914). 172. Impervious seed-conveyers—At maturity all seeds are moderately dry within, that is, for the preserva- tion of the endosperm during the dormant stage the moist- ure has been reduced to a minimum. To protect the contents against further loss of moisture which would injure or kill the embryo, the seed is enveloped by an impervious coating, which serves the double purpose of preventing the loss of moisture from within and the absorption of moisture from without. The protecting coating may be in immediate contact with the seed or it may be developed from some outer coating or organ. If an outer coating such as the glumes become hardened for this purpose, then the inner organs, lemma and pericarp are comparatively thin. The protective coating is developed from the seed-coat (Sporo- bolus), pericarp (wheat), lemma and palea (Panicum), glumes (Andropogon), rachis and glume (Tripsacum), sheathing bract (Coix), involucre (Cenchrus), or various combinations of these. In some cases, as in Cenchrus, several seeds are protected by the same outer coating. 173. Self-burial.— The dormant stage continues through the season unfavorable for germination, that. is, winter or a dry season. When the season for germination arrives, the seed, under the influence of moisture and higher temperature, gradually absorbs water, growth is started, the embryo swells and bursts through its sur- roundings, and germination has begun. Ordinarily the seeds are more or less covered with earth or debris by the action of the wind. But some seeds are aided in self- burial by the torsion of the awns they possess. The awns 138 A TEXT-BOOK OF GRASSES of Stipa (Fig. 36) have already been described (Par. 156). By the alternate drying and wetting they twist and un- twist, bend and straighten. The fruits, being provided with a sharp callus, covered with retrorse hairs, gradually insinuate themselves into the porous covering of the soil and finally into the soil itself. As the fruit is heavier at the base, it tends to fall point down. Awns of this kind are found upon the fruits of a number of genera, the burial being brought about by the rotation of the twisted portion or by the bending and straightening of a geniculate portion or by a combination of these. Straight awns or bristles that are antrorsely scabrous undoubtedly act in the same manner. Examples of tortion: Stipa, Aristida, Heretopogon, Chryso- pogon, Sorghastrum, Arundinella, Avena, Danthonia. Examples of antrorsely scabrous awns: Hordeum, Sitanion. 174. Water grasses.—The seeds of water grasses fall into the water and remain moist until germination. It has been shown that the seeds of Zizania palustris are injured by exposure for any considerable length of time* to the drying influence of the air. If the caryopsis at the time of germination is normally inclosed within outer envelopes, as lemmas or glumes, the embryo must be able to push its root and plumule through or around these parts. The usual method is for the root to break through the obstruction and for the plumule to push up between the parts. Some of the grains (wheat, rye, corn and kafir) are naked caryopsides and the growth of the embryo is unhampered. The grain or caryopsis of the oat is permanently invested by the lemma and palea. The root breaks through the back of the lemma near the base and the shoot pushes up between the grain and the lemma, emerging at the apex. The fruit of barley also consists of the grain inclosed in the lemma and palea and more or less adherent to the * For a full discussion of this subject, see Brown & Scofield, “Wild Rice: Its Uses and Propagation,’’ U.S. Dept. Agric. Bur. Pl. Ind. Bulletin No. 50. 1903 ECOLOGY 139 former. Emmer differs from wheat in that the whole spikelet con- taining several seeds becomes a fruit and breaks away from the rachis entire. The seed-like fruit of foxtail millet (Chetochloa italica) and proso millet (Panicum miliaceum) consists of a coriaceous lemma and palea tightly inclosing the thin-walled caryopsis. In all these cases the root breaks through the back of the lemma near the base by splitting the tissue and the shoot pushes up through the space between the caryopsis and the lemma, emerging near the tip. In Johnson-grass (Holcus halepensis) the grain is enveloped by the hard glumes and delicate lemma, sterile lemma and palea. The tissue of the glume appears to be too firm to permit the root to penetrate, for it passes through between the glumes. The fruit of tall oat-grass (Arrhenatherum elatius) consists of 2 florets, only the second of which is fertile. The root passes through the back of the lemma of this floret. Rice germinates in a manner different from that of the other fruits described. The caryopsis is inclosed in the much-flattened and keeled lemma and palea. The shoot breaks through the back of the lemma at the base and appears first as a pointed organ at the base of which later emerge the roots. 175. Propagation by bulblets.——Some grasses of high latitudes and altitudes produce, in the inflorescence, bulblets in place of ordinary spikelets. Bulblets are spikelets or portions of spikelets, in which the floral bracts have been transformed into small leaves, the whole becoming a vegetative shoot. These bulblets, which may be provided with young roots, fall off and produce new plants. A number of species may, under certain con- ditions, produce bulblets, while a few do this uniformly in certain regions (Poa bulbosa L.). Certain species (as Poa alpina L.) are ordinarily sexual but in extremes of alti- tudes and latitudes are asexual. PLANT SOCIETIES 176. So far as concerns their adaptation to environ- ment based upon condition of moisture, grasses may be 140” A TEXT-BOOK OF GRASSES divided into four groups—mesophytes, xerophytes, halo- phytes and hydrophytes. It should be understood that there is no sharp line between these groups. There are transitions in all directions. It is impossible to define in exact terms the limits that circumscribe these groups. One cannot, except approximately, say that plants growing upon soil containing certain definite limits of moisture shall be classed as mesophytes and that between other limits the plants shall be called xerophytes. Many other conditions modify the effect. One must judge rather by the sum total of the effect upon the plant, that is, the reaction to environment. If the plant shows general adaptations that aid it in resisting loss of moisture, the plant is a xerophyte. However, it often happens that the soil may contain sufficient moisture a part of the time and a deficiency at other times. So far as the plant is con- cerned the critical period is the growing season. A beech tree is a mesophyte in summer and a xerophyte in winter. In the summer there is sufficient moisture for its broad thin leaf-blades. In winter the ground freezes, the branches and twigs may freeze, moisture can not be sup- plied to so great a surface, and the surface is reduced by casting off the leaves. Nevertheless the beech is classed as a mesophyte. On the other hand, desert regions are visited occasionally by heavy rains and for a short time the soil may be saturated. But the plants of these regions are called xerophytes, because these periods of abundance are not of sufficient length to effect the general adaptations of the plants. 177. Mesophytes.—As the name indicates, this group includes those grasses that thrive under medium condi- tions of moisture. They are not water plants on the one hand, and on the other hand are not especially adapted to ECOLOGY 141 resist evaporation. They include most grasses of swamps, bogs, moist land along water-courses, and the inhabitants of forest and woodland. Grasses that become weeds in cultivated and waste soil usually belong to the meso- phytes. In general they have flat blades and will endure considerable alternation of conditions between a large amount of soil moisture and a moderate amount of drought. Familiar examples of mesophytes are the common cultivated grasses, such as corn, the small grains, sorghum, sugar-cane, the meadow grasses, common annual weeds, such as crab-grass and fox- tail, and the shade grasses of the tropical forests. Certain areas of open grass land include a mesophytic flora. Natural meadow land contains too much moisture to be classed as prairie. Grass land which contains an excess of water, but not enough to support strictly water plants, may be classed as bog, swamp, marsh or slough. The tundra of northern regions includes a large grass element. It is open wet land—wet because the subsoil is frozen and there is poor drainage. At high altitudes are found mountain meadows that support a mesophytic flora, even though the soil be dry, the low temperature being the determining factor. 178. Xerophytes.—These are grasses that are fitted to endure soil conditions in which the moisture content is deficient. They are, in consequence of this deficiency provided with especial adaptations to resist evaporation. In xerophytes belonging to other families of plants, water- storing organs are common, but among grasses this adaptation is rare. Panicum bulbosum H. B. K., of New Mexico, is provided with a corm which probably acts as a storehouse of moisture. The corms at the base of some species of Melica, and the chain of corms in 142 A TEXT-BOOK OF GRASSES Arrhenatherum elatius bulbosum (Par. 241) may serve for storage, although the plant last mentioned is not a xerophyte. In general, xerophytic grasses have become adapted to their surroundings by the production of impervious epidermis or of mechanical tissue in leaves and stems and by fine foliage. Roll-leaves, described in a preceding paragraph (Par. 139), are common. The foliage of xero- phytic grasses is nearly always firm and hard from the excessive development of sclerenchyma fibers and other mechanical tissue and the relative lack of soft parenchy- matous tissue. The stomata are in protected places, in the longitudinal furrows of the blades or on the inside of rolled blades. All these structures tend to retard evapo- ration and prevent the loss of water which cannot readily be obtained from the dry soil. There are four chief habitats where xerophytic grasses may be found,—prairie, sandy soil, rocks and desert. 179. Prairie is open grass land where the soil is deficient in moisture. If open grass land occurs upon soil in which there is no deficiency of moisture it may be swamp, tundra or mountain meadow as indicated under a preceding paragraph (Par. 177). Prairies are found as isolated areas interspersed through regions that are chiefly occupied by a mesophytic flora, as the eastern united States. In Iowa and Missouri, they occupy large areas, with wood- land interspersed. A vast prairie extending from Texas northward far into Canada is called the Great Plains. Similar regions in western Asia are called steppes and in South America are called pampas and llanos. In Central America and in some other countries, they are known as savannahs (or savannas). The dominant plants of these prairies and plains are grasses. In general, there are many species producing rhizomes or stolons so that much ECOLOGY 143 of the surface is covered by a sod. Stipas and various Andropogonee, especially Andropogon, are often dominant species. Over much of the Great Plains, a single species, Bulbilis dactyloides (buffalo-grass) or this combined with Bouteloua gracilis (grama-grass) gives a characteristic aspect to the vegetation. Those grasses often called “short grasses’? may occupy vast areas almost to the exclusion of other species of plants. Farther south, the Bulbilis is replaced by Hilaria cenchroides (curly mes- quite). This portion of the Great Plains is known locally as the “short-grass country’? because the uniform com- pact curly growth is only a few inches high. The regions described above are known as semi-arid regions. 180. Sandy soil.—Plants characteristic of sandy soil are sometimes called psammophytes. The best illustration of this kind of xerophytes may be observed upon sand- dunes. These are found along sandy seacoasts of temper- ate regions, the sandy shores of lakes, along the banks of rivers, especially in arid regions, and in dry interior regions far removed from bodies of water. Such areas are found in the United States along the Atlantic seaboard, especi- ally on Cape Cod, along the Great Lakes, especially the eastern and southern shore of Lake Michigan, and along certain large rivers, such as the Columbia east of the Cascades, and the Arkansas in western Kansas. Large areas of sand hills are found in interior regions such as central Nebraska. 181. Sand-dunes may be so far removed from water or in such rapid motion that no vegetation can be sup- ported. Dunes near the sea, though completely dried out at the surface may be moist beneath on account of the drawing of water from below by capillary attraction. Many grasses of sand-dunes produce a well-developed 144 A TEXT-BOOK OF GRASSES system of rhizomes. These do not form a sod as the soil is too poor in plant-food to support plants sufficiently near together. Representative species are Ammophila arenaria and Spartina patens (Ait.) Muhl. along the sea- coast, Calamovilfa longifolia (Hook.) Hack. in the Great Plains, Elymus flavescens Scribn. & Smith in the Colum- bia River basin and Elymus arenarius L. of the Alaskan seacoast. The first mentioned, Ammophila arenaria, called beach- or marram-grass, is a typical sand-binder. It not only produces widely extending rhizomes which may reach great depth, but the culms push upward as the sand drifts around them. (Par. 93). 182. Pine-barrens.—Sandy regions in which there is a sparse forest-cover represent xerophytic conditions, though less marked than those of dune areas. The pine- barrens of the Atlantic coastal plain are typical of these regions. They are mostly level areas covered with open pine woods. Southward they include the turpentine country, and in Florida they become the ‘‘high pine land” and the still more xerophytic ‘‘scrub.”? These regions are the home of the smaller species of Panicum and many other peculiar grasses. 183. Rocks.—On account of the impervious sub- stratum, plants growing upon rocks are insufficiently provided with water unless near some source of supply, such as spray from a waterfall, springs, melting snow and the like. Hence xerophytic grasses may occur in a meso- phytic region. Such grasses are bunch-grasses as rhizomes do not develop under these conditions. 184. Deserts.—Regions in which the deficiency in the water-content of the soil is greater than in prairie and in which the humidity of the atmosphere is very low, are called deserts, or arid regions. Deserts owe their aridity ECOLOGY 145 primarily to scanty rainfall rather than to soil conditions, as in the case of rocks and sand-dunes. They are so situated that the prevailing winds have been previously deprived of their moisture by passing over mountains. The chief desert region of the United States is found in the Great Basin from the plains of the Columbia in eastern Washington southward through Arizona to the Mexican plateau. The aridity increases southward and reaches its maximum in the Colorado Desert of southeastern California. The annual rainfall is less than 20 inches, often less than 10 inches. On account of the higher tem- perature and longer summers the aridity increases southward even though the rainfall may remain the same. Other desert regions are found along the Pacific slope in Peru and northern Chili, in the interior of Australia and Asia, and the Sahara Desert of north Africa. The perennial grasses of deserts are for the most part bunch-grasses and on account of the scarcity of moisture the bunches are widely scattered. In contradistinction to the other xerophytic regions, deserts are inhabited by several species of annual grasses. Such grasses are adapted to the distribution of the rainfall. This usually comes in occasional heavy showers. Immediately after such a shower the seeds of annuals germinate, develop rapidly and mature seed before the effects of the shower have passed away. This adaptation to seasonal moisture is especially marked if the showers are concentrated within a certain period of the year forming a rainy season. In southern Arizona there are usually two such rainy sea- sons, one in winter and one in summer, with a correspond- ing growth of annuals, many of them grasses, after each period of rainfall. In all desert regions the grasses tend J 146 A TEXT-BOOK OF GRASSES to collect in depressions or drainage basins where the water from showers remains longest. 185. Halophytic grasses are those that grow in soil containing an excess of mineral salts. In general they are known as salt-marsh plants. They are found in the salt- marshes of the seacoast and of interior alkali regions. The soil that supports halophytes may not be lacking in water, but the presence of soluble salts increases the density of the soil-water and hence renders it less easily absorbed by the root-system of the plant. Although erowing in water or wet soil, the plants have difficulty in obtaining the necessary water-supply and consequently, to avoid injury from loss of water through evaporation, xerophytic characters have been developed. Among these characters may be mentioned harshness due to the pres- ence of mechanical tissue, roll-leaves, and succulence. Familiar examples of halophytic grasses are Spartina glabra Muhl. of the Atlantic coast salt-marshes and Distichlis spicata (L.) Greene of the interior alkali plains. 186. Hydrophytes are water plants. They grow in the water, either submerged or from soil that is perma- nently saturated. Only a few grasses, such as Hydrochloa caroliniensis Beauv., are nearly or quite submerged. But there are many that inhabit permanent fresh-water or brackish marshes. To this group belong Zizania palustris L. (Indian rice), Zizaniopsis miliacea (Michx.) Ddll & Asch., Paspalum dissectum L. and P. repens Berg. Pani- cum elephantipes Nees and Echinochloa sabulicola Nees of the American tropics are succulent hydrophytes, grow- ing in several feet of water. Paspalum repens, of Pan- ama, forms long runners that float upon the surface of the water, buoyed up by their inflated sheaths. Swamp-grasses as distinguished from marsh-grasses ECOLOGY 147 are usually to be classed with mesophytes, because they are subject to much fluctuation in the water-supply. The soil may be saturated at one time and moderately dry at another time. Swamp-grasses often show xerophytic characters, especially roll-leaves. During the early part of the growing season, particularly in the North, the air at least during the day is warm while the roots are im- mersed in the cold substratum. There is thus danger of the loss of water by evaporation from the leaves faster than the cold sluggish root-system can supply it; hence the presence of roll-leaves. GEOGRAPHICAL DISTRIBUTION 187. Geographical distribution of plants is their range or dissemination over the surface of the earth. The present distribution is the result of causes which have acted through an indefinitely long period of time and often over areas of continental extent. Every species of plant occupies its present area by virtue of its ability to adapt itself to its environment. If the environmental conditions change, the plants concerned must become adapted to the new conditions, or they are forced to mi- grate, or, failing in this, they become extinct. It is not the purpose here to discuss the causes that have brought about these changes, but merely to outline the present distribution of the grass family. For a further discussion the student is referred to the works dealing with the evolution of plants, especially those of Darwin, Wallace, Hooker and Gray. Darwin: “Origin of Species.”” Wallace: ‘‘Darwinism,” “Island Life,” ‘The World of Life,’ and other works. Hooker: “‘Distri- bution of Arctic Plants.” Gray: ‘Collected Essays.” 148 A TEXT-BOOK OF GRASSES 188. Distribution of grasses.—As stated in a preceding paragraph (Par. 121), the grasses are represented in all parts of the earth’s land-surface where the conditions are suitable for the growth of flowering plants, from sea-level to the snow-line on the high mountains, from Greenland to the antarctic continent, from swamp to desert, and from the deep forest to the clefts of the boldest cliff. The great tribes Andropogonese and Panicez predominate in the warmer regions, while the Agrostidese and Festucese predominate in the cooler regions. Space will not permit of detailed references to the distribution of genera and species. Small genera are often much restricted in their area while large genera are usually distributed over a wide area. The great genera Andropogon, Panicum, Paspalum and Eragrostis are found throughout the tropics of both hemispheres. Muhlenbergia and Bouteloua, also _ large genera, are confined to the American continent and are especially well represented on the Mexican plateau. Poa and Festuca are found in all continents, but mostly in: the cooler regions, extending to the northern and southern limit of vegetation, and well represented in alpine regions, even of the high mountains of the tropics. 189. Distribution of species——Species also vary greatly as to the extent of the area in which they are found. Certain agressive species known as weeds are now wide- spread over extensive areas of both hemispheres. Crab- grass (Syntherisma sangutinalis ) and goose-grass (EHleusine indica (L.) Gaertn.) are familiar examples. Heteropogon contortus (L.) Beauv. is an example of a similarly wide- spread species which is native throughout its area. Many species of the seashore and of marshes are likewise exten- sively distributed. Spartina glabra Muhl. and Ammophila arenaria are found on the seacoast of Europe and America, ECOLOGY 149 the one in salt-marshes the other upon _ sand-dunes. Many species have a circumpolar distribution* and often extend southward along the mountain ranges. Poa alpina, found at sea-level within the arctic circle, extends southward in the Rocky Mountains to Colorado where it is found on alpine summits. 190. Circumpolar distribution Those species that are indigenous to North America and Eurasia usually show evidence, by a present circumpolar distribution, such as that of Poa alpina and many others, of a common origin in polar regions; or they suggest the probability of such distribution in the past. During a preceding warm epoch, when vegetation zones lay farther north than now, many species were circumpolar that afterward were driven south by the succeeding ice period. These species survived only where they found conditions suited to their requirements. Some were driven along the moun- tain ranges; others were driven along the coastal regions. As the climates of the northeastern coasts of North America and Asia are similar, there are many cases where the same or similar species of plants inhabit both regions.| Among grasses one notes the genera Diarrhena and Zizania, each represented by similar species in the two regions and not found elsewhere. 191. Generic distribution—Sometimes large genera show a special development in certain areas although there may be scattering species in regions remote from the areas of greatest development. The genera Bouteloua and Muhlenbergia, mentioned above, are represented by numerous species on the tableland of Mexico, although certain species of the former are found as far south as *Hooker, ‘‘Distribution of Arctic Plants.” 7Gray, “Analogy between the Flora of Japan and that of the United States.” 150 A TEXT-BOOK OF GRASSES Argentina, and of the latter as far north as New England, and west even to eastern Asia. The subgenus Dichan- thelium of the immense genus Panicum is represented by nearly 100 species in southeastern United States, but there are a few species extending to the state of Washing- ton, and others through the West Indies and Mexico to northern South America. Danthonia, with over 100 species, centers in South Africa, but several species are found in America and other countries. CHAPTER XIV TAXONOMY OR CLASSIFICATION UNDERLYING all present systems of classification of living organisms is the doctrine of evolution, that all organisms are descended from other more or less dis- similar organisms and that in the course of such descent there is an inherent tendency to vary. Classification is an attempt to group organisms in a manner that shall represent, as nearly as our knowledge permits, actual genetic relationships. 192. Species.—The size and limits of the proposed groups are influenced by convenience. The unit of bio- logical classification is the species, a term however which is difficult to define. A species includes all those individuals _ that show as much resemblance to each other as they might be expected to show if they were all known to be descended from a common and comparatively recent ancestor. As the genetic history of the individuals is not known, the grouping into species is an expression of the opinion of the biologist, and his opinion is based upon judgment and experience. It should be kept in mind that a species is a taxonomic idea* and is not an entity the existence of which can be proved. For this reason, taxonomists often disagree as to the limits of species. The more experience a botanist has had with plants, especially with living plants in their native habitat, the *“The name itself is but the expression of a taxonomic idea.’’ Greene, “Landmarks of Botanical History,’ p. 122. (151) 152 A TEXT-BOOK OF GRASSES more may his judgment be trusted when defining the limits of species with which he is familiar, and the more nearly should his taxonomic ideas approach the truth. The truth for which the taxonomist seeks is a knowledge of genetic relationships; the grouping of organisms into species, genera and other divisions is a convenience which is intended as nearly as may be to express this truth. In the ever-diverging lines of descent, certain groups of individuals have been cut off, as it were, from their allies, so that in these cases the species of the taxonomist prob- ably does express the truth. In other cases the groups are in process of formation and separation, and are not actually distinct. It is here that the taxonomist meets his greatest difficulties. Even with complete knowledge, his taxonomic ideas can be no more distinct than are the groups as they exist in nature. In proportion to his lack of knowledge is the probability that his taxonomic ideas fail to represent the truth. It follows, then, that a classification submitted by a botanist is accepted by his co-workers in proportion to their faith in his judgment and their knowledge of his experience. The members of a complex group of allied species may have been defined and their limits placed with approximate accuracy and yet it may be impossible definitely to refer every individual to its proper species. According to the degree of divergence of allied species in their descent from a common origin, there are a greater or less number of intermediate indi- viduals. The existence of individuals intermediate between two species should not invalidate those species; rather they emphasize the fact that species do not exist in nature, that they are ideas according to which most of the indi- viduals may be classified. 193. Genera.—A genus is a group of species that are TAXONOMY OR CLASSIFICATION 153 thought to be closely related genetically. The species of a genus will show similarity in fundamental characters, such as the structure of the flowers and fruit, and usually also a similarity in habit, or general aspect. Familiar genera are the oaks, the pines, the asters, the golden- rods; or, among grasses, the blue-grasses and the wheat-grasses, the millets and the bromes. As genera do not exist in nature, but represent the taxonomist’s ideas as to groups of related species, botanists may not agree as to the limits of genera. The size of genera, that is, the number of species included, is some- times a matter of convenience. Conservative botanists would probably not recognize Panicum and Paspalum as separate genera, when considering the generic characters only, but each group contains such a large number of species that the two have been kept distinct for conve- nience. Some species are so different from their nearest allies that they cannot be consistently grouped with other species. Such a species stands as the sole rep- resentative of its genus, and the genus to which it belongs is called a monotypic genus. It not infrequently happens that after a monotypic genus is established other species are discovered, which are assigned to it, and it ceases to be monotypic. In contrast with monotypic genera are others, such as Panicum, Andropogon and Poa, with hun- dreds of species. Large genera may sometimes be con- veniently divided into smaller groups, such as subgenera and sections. From a nomenclatorial standpoint the term monotypic is used to indicate genera with only one species at the original place of publication. Cook suggests the word haplotypic for such genera. (Amer. Nat. 48:311. 1914.) 154 _A TEXT-BOOK OF GRASSES 194. The grass family and its subdivisions—The genera of plants are grouped into families, and these into orders and higher divisions of the vegetable kingdom. The grass family is called Poaceze or Graminee, and this with the Cyperacee (sedges) constitute the order Poales or Glumiflore. The term Poales is used for the order in the “North American Flora,’ the termination -ales being uniformly added to a generic stem to form the names of orders. Glumiflore is used by Engler and Prantl in their ‘‘Pflanzenfamilien.’’ Glumacez is used by Ben- tham and Hooker (‘‘Genera Plantarum’’) as the name of the series that includes Eriocaulee, Centrolepidee, Restiaceze, Cyperaceze and Graminez. The classification here adopted is in the main that of Bentham and Hooker (‘‘General Plantarum’) and of Hackel (‘“‘Pflanzenfamilien’”’). The latter author will be followed in the enumeration of the tribes. Although Hackel’s classification is in some respects artificial, it is on the whole the most natural arrange- ment yet proposed. The family Poacez has been divided for convenience into 2 series and 13 tribes. 195. The 2 series of tribes—Modern agrostologists usually divide the genera of grasses into 2 series. The first series Panicoideze (or Panicaceze), the more highly developed or modified, is characterized as follows: Spike- lets with 1 terminal perfect floret and often a staminate or neutral floret below; an articulation below the spikelet, sometimes in the pedicel, sometimes in the rachis, some- times at the base of a cluster of spikelets, the spikelets falling away at maturity singly or in groups, or with portions of the rachis; spikelets usually more or less dorsally compressed, rarely laterally compressed. ‘The second series, Pooidee, is characterized as follows: Spikelets with 1 to many florets, the imperfect ones when present usually being above; rachilla often artic- TAXONOMY OR CLASSIFICATION 155 ulated above the glumes; spikelets usually laterally compressed. There are exceptions to all these characters. In some cases the exceptional genera are clearly related to others that conform to the above definitions. Other genera are more or less anomalous and are tentatively placed in the category to which they seem most nearly related. In Isachne the lower floret is perfect and similar to the upper, but it is evidently allied to Panicum and hence is placed near that genus in the first series. Several genera, such as Sphenopholis, Spartina and Alopecurus, have an articulation below the spikelet so that the latter falls from the pedicel, in which respect they agree with the first series, but in most characters they agree with the second series, in which they are placed. In Phalaridez of Series II the imperfect florets are below the terminal perfect one. 196. The tribes of grasses.—There are 6 tribes in the first series and 7 in the second. The following key to these tribes is not made to cover exceptional genera, since to do this for the sake of'a comparatively few genera would make the keys unnecessarily complex. Series [ A. oie ig round or dorsally compressed; hilum short B. Lemmas and palea very thin and hyaline, the glumes much thicker. c. Inflorescences moneecious, the staminate and pistillate flowers in different parts of the same plant............ Tribe 1. MaypEax cc. Inflorescences not moneecious, usually a (Chap. 15). mixture of perfect and staminate or neutral spikelets............. Tribe 2. ANDROPOGONE BB. Lemmas and paleas membranaceous or (Chap. 16). thicker, not thin and hyaline. c. Lemmas thinner than the glumes. 156 A TEXT-BOOK OF GRASSES p. Spikelets falling off singly or in groups from a continuous rachis; the first glume usually larger than the second. Tribe 3. NazIezx DD. Spikelets falling off singly from the (Par. 212). ultimate branches of a panicle; first glume smaller than the second. Tribe 4. MELINIDEX cc. Lemmas thicker than the a hard- (Par. 213). CMERS otcct crete pense cabs Tribe 5. PANICEZ AA. Spikelets laterally compressed; hilum linear* (Chap. 17). Tribe 6. OryzE= (Chap. 18). A AEE WONG. Usacvi sss boc eee ees Tribe 13. BAMBUSE= AA. Culms herbaceous. (Par. 270). B. Spikelets in spikes or spike-like racemes. c. Spikelets crowded on one side of the PRO so oes Soe ee Tribe 10. CHLORIDEZ cc. Spikelets on opposite sides of the rachis. (Chap. 22). Tribe 12. HorDEx BB. Spikelets in contracted or open panicles. (Chap. 24). c. Spikelets with 1 perfect floret. p. Perfect floret with 2 sterile lemmas EAE. eens Tribe 7. PHALARIDEX pp. Perfect floret solitary, no sterile lemmas (Chap. 19). below....... .Tribe 8. AGROSTIDEX cc. Spikelets with 2 or more florets. (Chap. 20). Dp. Lemmas awned from the back; glumes usually longer than the first lemma. Tribe 9. AVENEX pp. Lemmas awned from the tip or awn- (Chap. 21). BIR Aor oe ee id oe ere. Tribe 11. FestucE= (Chap. 23). THE MORE IMPORTANT GENERA OF GRASSES 197. Hackel recognizes over 300 genera of grasses, and some writers, including the author, recognize many more, probably 400 in all. Only a few of the more im- portant genera are described in the present work, the selection being based upon the size of the genus, or the ey In Gray’s “‘Manual” this tribe is placed in Series II (Gray, Man. ed. 7, p. 88. TAXONOMY OR CLASSIFICATION 157 economic value of included species. Keys are given to all genera native or commonly cultivated in the United States. 198. Characters used in classification—The con- sensus of botanical opinion is that genetic relationships among phanerogams are best shown by the structure of the flowers. Grasses are no exception to this rule and hence the classification is based upon the structure of the spikelets. The preceding key indicates the characters used in classifying the tribes. The classification appears to be somewhat artificial, but nevertheless it brings to- gether in the same tribe genera that are evidently related. But it also in some cases, separates into different tribes genera that are closely related. Reference will be made to some of these cases again in the appropriate place. 199. Phylogeny.—As to the phylogeny of the grasses, it is probable that the most primitive existing forms are those in which the spikelet consists of a series of flowers in the axils of herbaceous bracts. The simpler genera of Bambusex, such as Arundinaria, probably represent the lower or more primitive forms. It must not be understood that this tribe is, as a whole, less developed than the other tribes. Some genera are highly developed. There is good ground for believing, however, that the Bambusez arose from forms more primitive than those that gave rise to the other tribes. The Festucez and Hordex probably come next in phylogenetic development, while the Andro- pogonese and Panicee are highly developed. The exact relationship of the various tribes and the smaller groups is, of course, for the present largely a matter of conjecture and individual opinion. Phylogenetic ideas are expressed by the grouping of forms rather than by attempting to trace lines of descent. We may group allied species into 158 A TEXT-BOOK OF GRASSES genera and allied genera into higher groups without com- mitting ourselves as to how the various groups came to be what they are. The modern tendency is toward a grouping of species in all large genera. Some of these groups are recognized under the formal titles of sub- genera, sections and subsections. But it is often con- venient to form smaller groups centering around well- known or widespread species. Ascherson and Grabner bring together closely allied species under the heading Gesammtart (Syn. Mit.-Eur. Fl.). In our recent revision of the North American Species of Panicum (Contr. U. §. Nat. Herb. 15) these minor groups or species were indicated by the plural of the leading species, e.g., the allies of Panicum dichotomum were grouped under Dichotoma. CHAPTER XV TrisE I. MAYDE This tribe is scarcely more than a division of the next tribe, Andropogonez, from which it differs in the sepa- ration of the staminate and pistillate inflorescences. The structure of the spikelets in the 2 tribes is similar. Key TO THE GENERA OF MAYDE% A. Staminate and pistillate spikelets in separate inflorescences, the former in a_ terminal tassel, the latter in the axils of the leaves. B. Pistillate spikes distinct, articulated........EUCHL#NA BB. Pistillate spikes grown together forming (Par. 201). RE PSMA Ot cola: 5,2 a tk chic ee VE ZEA (Par. 202). AA. Staminate and pistillate spikelets in separate portions of the same spike, the pistillate below. B. Spikes short, the 1- to 2-flowered pistillate portion inclosed in a bead-lke sheathing RCA oS hg crates Aa eet bee ee nee Corx (Par. 203). BB. Spikes many-flowered, the pistillate portion breaking up into several 1-seeded joints; no bead-like sheathing bract.............TRIPSACUM (Par. 200). 200. Tripsacum L.—The terminal inflorescence con- sists usually of a cluster of spikes the lower portions of which are pistillate and the upper portions staminate. The pistillate portion consists of a series of joints which disarticulate at maturity forming bony cylindrical or angled seed-like parts made up of the thick axis and an imbedded spikelet. The spikelet consists of a hard first glume which closes the spikelet within the joint of the rachis, a thinner second glume, a sterile lemma with a (159) 160 A TEXT-BOOK OF GRASSES palea, and a fertile floret, the latter all hyaline. The staminate spikelets are in pairs on a slender rachis. The spikelet consists of 2 coriaceous glumes and 2 florets with stamens, the lemmas and paleas being hyaline. Besides the terminal inflorescence there are usually in the axils of the leaves others that may be reduced to a single spike. One species, 7’. dactyloides L., a coarse perennial found through eastern and southern United States, is an excel- lent forage grass, sometimes called gama-grass. A few other species are found in Mexico. 201. Euchlena Schrad—Teo- sinte. The staminate flowers are in a terminal panicle while the pistillate are in spikes in the axils of the leaves. The staminate spikelets are similar to those of Tripsacum. The spike of pistillate spikelets breaks up at maturity into rhomboidal seed-like joints. The styles are very long and protrude from the top of the inclosing leaf-sheath. The best known species is E. mexicana Schrad. (Fig. 11), a native of Bite canen cis, Moree. The + Con a Distillate inflorescence, X ¥4 resembling corn, cultivated in the ee by, Sec. Bull southern United States as a for- age plant, chiefly for green fodder. There are 1 or 2 other species in Mexieo and Central America. A hybrid between Euchlena and Tripsacum is described by Collins and Kempton. The pollen was fur- nished by a variety of Euchlena from Durango, Mexico (Journ. Wash. Acad. Sci. 4: 114. 1914). MAYDEA 161 202. Zea L.—Indian corn, maize. This genus is represented only by the cultivated maize (Z. mays L.), and is not known in the wild state. There are several well-marked varieties, such as dent, pop and sweet, which are thought by some to be distinct species. Like the pre- ceding genus, the staminate inflorescence is separate from the pistillate. The former is a terminal panicle called the tassel and the latter, a thick spike surrounded by leafy bracts or husks, is called the ear. The staminate spikelets are in pairs on the rachis, 1 sessile and the other pediceled, each 2-flowered, the thin lemmas and paleas being shorter than the firm glumes. The ear consists of several close rows of pistillate spikelets upon a greatly thickened axis, the cob. The spikelet consists of 2 glumes, a sterile lemma with a small palea, and a fertile lemma and palea. All these bracts remain at the base of the mature grain as coriaceous chaff on the cob. The numerous single styles protrude from the ear and form the “‘silk.”” There is a potential ear in every leaf-axil but usually only one de- velops into a perfect ear. In one variety, called pod-corn, each kernel is enveloped in the elongated floral bracts. There has been much speculation as to the origin of corn. Some have thought that it has been developed from Teosinte, others that the original wild form has become extinct. It is more likely that it is a hybrid between Teosinte and an unknown or extinct species re- sembling pod-corn. (Collins ‘““The Origin of Maize,” Journ. Wash. Acad. Sci. 2:520. 1912.) Corn has been cultivated from prehistoric times by the early races of American aborigines, from Peru to middle North America, and is now cultivated throughout the world in warmer regions for food for man and do- mestic animals. The chief varieties are dent, the common commercial field variety, flint, formerly common in the K 162 A TEXT-BOOK OF GRASSES northern states, sweet and pop. A starchy variety called flour corn is grown in South America and pod-corn is occasionally cultivated as a curiosity. A form with variegated leaves is culti- vated in gardens for orna- ment. (For further notes on classification see Mont- gomery, “The Corn Crops” 15. . 1913.) 203. Coix L.—Only 1 species is common, the Job’s-tears (C. lacryma-Job. L.) (Fig. 12), which is cultivated for orna- ment and escaped as a weed in the tropics. It is a handsome broad-leaved species, reaching a height of 4 to 6 feet. The inflorescences are several on each plant, each being at the end of a long peduncle on the end of which is an urn-shaped indurated bead-like bract, supporting the base of the simple spike, pistillate at base and staminate above. The pistillate portion consists of 1 fertile spikelet - with 1 or 2 sterile ones, inclosed in i the urn-shaped bract, the 2-cleft style and the tips of the sterile spike- lets protruding through the open- Fic. 12, Coix lacryma- ing at the top. The glumes of the Jobi. Inflorescence show- ing several pistillate beads, fertile spikelet are broad, hyaline the staminate spikes pro- truding, x2. with membranaceous tips, the lemmas MAYDEZ 163 and palea delicately hyaline. The staminate upper por- tion of the inflorescence also protrudes from the opening for an inch or two. This consists of a few spikelets in pairs, the structure being similar to that described above for the other genera. At maturity the staminate portion of the inflorescence disarticulates, the sheathing bract containing the seed forms an ivory-like ovoid fruit, from white to bluish gray in color, that separates by a joint from the peduncle. These fruits are used as beads for ornament. CHAPTER XVI Trise II. ANDROPOGONE TuHIs great tribe is represented in the warmer regions of both hemispheres but is absent from the arctic and alpine regions and is poorly represented in the cooler temperate regions. The spikelets are usually arranged in pairs at each joint of a spike-like raceme, 1 sessile, the other pedicelled. The rachis of the raceme is usually articulated and breaks up at maturity into joints. The racemes are often woolly with long hairs and may be arranged in a compound inflorescence. Sometimes the racemes are reduced to the terminal joint of 3 spikelets, in which case the compound inflorescence is a panicle, as in Johnson-grass. The spikelets nearly always consist of 2 glumes, at least 1 of which is firm or indurated, a sterile lemma, and a terminal fertile floret. The bracts above the glumes are usually thin and hyaline. The fertile lemma often bears a bent or twisted awn. Grasses of this kind are commonly abundant on savannas and plains in the tropics and in prairie regions of the United States, and many species are useful forage grasses. There are about 50 genera in the tribe but only a few contain species of interest to Americans. Of the 5 sub-tribes, only 2 will be mentioned here. Key TO THE GENERA OF ANDROPOGONE A. Axis of the spike glabrous, much thickened, with excavations holding the spikelets; fertile lemma awnless. (164) ANDROPOGONEA 165 B. First glume flattened or somewhat convex. Florida POUR sey ip anne CaN? SNe AS OO MANISURIS. BB. First glume hard and globular, pitted. BOM LO? ATIZONS,. s/o seek obs Guanes RyYTILIx. AA. Axis of the spike or raceme hairy, not exca- vated nor greatly thickened; fertile lemma usually awned. B. Spikelets all alike. c. Axis of racemes continuous. D. Racemes in a narrow spike-like panicle; spikelets awnless. Florida........... IMPERATA. pp. Racemes in a broad fan-shaped panicle; solkelete-awmedlie: oe saa eee MIScANTHUS cc. Axis of racemes breaking up into joints; (Par. 204). racemes in a much-branched panicle on a main axis. Pe SUSIE Ta WHE... cua awe ao latins week ERIANTHUS (Par. 206). DH; Spikelets awnless. 0s. Fee knee SACCHARUM BB. Spikelets not all alike, one of the pair perfect, (Par. 205). the other staminate, neutral or reduced to a pedicel. C. Brule spikelet pedicelled, with a long plumose awn; sterile spikelet nearly sessile, anal. ee nee Toca. TRACHYPOGON. cc. Fertile spikelet sessile; sterile spikelet pedicelled; axis articulate. pD. Spikelets ‘awnless; raceme solitary, ter- minating the SS ER eM AN et ELIONURUS. DD. Spikelets awned; racemes 1 or more from each sheathing bract but not solitary on the culms; sometimes re- duced to the terminal joint of 3 spike- lets and borne in panicles. E. Sessile spikelets all alike in the same raceme. F. Racemes several-flowered......... ANDROPOGON FF. Racemes reduced to 1 or 2 joints, (Par. 208). these in panicles. G Awn several inches long........ CHRYSOPOGON. ac. Awn short. H. Plants perennial, without rhi- zomes; sterile spikelet re- duced to a pedicely....c.28 5 SORGHASTRUM. HH. Plants perennial, with rhi- zomes, or annual; sterile spikelets Stamina. 7025). 50 Hocus EE. Sessile spikelets at the base of the (Par. 210). spike different from the others. 166 A TEXT-BOOK OF GRASSES F. Racemes solitary at the ends of the DraRRUOE So coset on te pe HETEROPOGON. FF. Racemes in pairs from a sheathing bract, these in panicles.......... CYMBOPOGON (Par. 209). SustrisE SACCHAREA Spikelets perfect, all alike. The genera here mentioned have large compound inflorescences of woolly racemes. 204. Miscanthus Anderss—Tall coarse perennials with large panicles, axis of the racemes not articulated. One species, M. sinensis Anderss. (Eulalia japonica Trin.) (Fig. 13), a native of eastern Asia, is cultivated for orna- ment. This grass grows in large bunches, with numerous narrow leaves, 2 to 4 feet long, tapering to a slender point, slender upright flower-stalks 4 to 6 feet high bearing a 7 Wife fan-shaped cluster of woolly yy, ee Ze spikes 6 to 12 inches long. There ES GZ 7 VW — are 3 varieties in cultivation: var. = VW ' Ue variegatus, with striped leaves; chi ~~ var. zebrinus, with banded leaves; and var. gracillimus with leaves much narrower than in the other forms. ‘Two other species are occasionally cultivated,— M. sac- charifer Benth., with nearly or quite awnless spikelets, and M. nepalensis Hack. (Himalaya fairy- grass), with spikelets one-fourth as long as the brown involucral hairs. tifa 8 205. Saccharum L.—The best- Fia.'13. Miscanthus sinensis. ; : Plant much reduced, spikelet, known species 1S the sugar-cane 3. (U.S. Dept. Agr., Div. fou. Baa), (S. oficinarum L.) (Fig. 14), a tall ) Oe ae eS =e Sea a * \ — = NS ; ys i SN — 5 Bex wee \ \\V \} Ls EB Zs = EZ rx ANDROPOGONEZ 167 coarse grass with broad blades and a large woolly plume- like panicle as much as 2 feet long. The unawned spike- lets are similar to those of the preceding genus, but the axis of the racemes is articu- lated. The native country of is sugar-cane is not known, but it is now cultivated in all tropical countries. Although it produces seed occasionally it is propa- gated by cuttings of the stem. 206. Erianthus Michx.—The inflorescence resembles that of the preceding genus, but the spikelets are awned. One species (E. Ravenne Beauv.), a native of the Mediterranean region, is cultivated for ornament under the name of plume-grass, wool- grass, Ravenna-grass, or hardy pampas-grass. It is atall peren- _ Fie. 14. Saccharum officinarum. nial with narrow blades and a i eee pei as apinies eas ; E a flower (c), X3. (U.S. Dept. Agr., plume-like panicle, as much as 2_ Div. Agrost., Bull. 20.) feet long. SusTrRinE EUANDROPOGONEA 207. Spikelets not all alike, the sessile one of each pair fertile, the pedicelled sterile, sometimes reduced to the pedicel. The genera described below are included by some authors as sub-genera of the large genus Andro- pogon. The axis of the raceme is articulated. The awn is very large and strong in some genera (Hetero- pogon, Chrysopogon), is geniculate and twisted, and bears at the base of the spikelet a strong sharp hairy 168 A TEXT-BOOK OF GRASSES Fie. 15. Erianthus divaricatus. Plant reduced; spikelet, the two glumes, and : the fertile lemma with lower portion of awn, X3; flower, X65. ANDROPOGONEZ 169 callus, the whole much resembling the awned fruit of Stipa spartea. 208. Andropogon L.—Sessile spike- lets all alike in more or less elongated racemes. The racemes may be single or in pairs, or rarely 3 or 4 from a sheath- ing bract, or they may be in naked panicles. The species are usually coarse perennials that inhabit prairies, hills, pine-barrens and other dry places. Some species are important native forage grasses. Two of these are common on the prairies of the Mississippi Valley, the little bluestem (A. scoparius Michx.) and the big bluestem (A. furcatus Muhl.) (Fig. 16). The first species has solitary racemes from each bract or spathe, and is a representative of the subgenus Schizachyrium. The other has 3 or 4 racemes in a naked digitate cluster. A common but less valuable species, the broom-sedge (A. virginicus L.), is found in the Atlantic states on sterile soil. This large genus of hundreds of species is spread over the warmer regions of both hemispheres. 209. Cymbopogon Spreng—tThis genus resembles Andropogon in having racemes in pairs from sheathing bracts, but differs in that 1 or 2 of the lower- most pairs of spikelets of at least 1 of the racemes, are both staminate. In the economic species the pairs of racemes Fie. 16. Andropo- gon furcatus. Inflores- cence, Xl. A joint of the rachis with a fertile spikelet below an a staminate spikelet above, X65. 170 A TEXT-BOOK OF GRASSES are arranged ina large compound panicle. Several species of this genus* furnish volatile essential oils and some are cultivated for this purpose. The most common cultivated species, both from India, are citronella-grass, C. Nardus (L.) Rendle, and lemon-grass, C. citratus (DC.) Stapf. 210. Holcus L—Racemes reduced to the terminal joint which consists of a fertile spikelet and a pair of staminate spikelets, these racemes or groups arranged in panicles. One species, H. halepensis L. (Fig. 17), the well- known Johnson-grass, a native of the Old World, is now naturalized in America. This is a valuable forage-grass but on account of its tendency to spread in cultivated fields and the difficulty with which it is eradicated it can- not be recommended. It is a coarse perennial with creep- ing rhizomes. The other important species of this genus is sorghum (H. Sorghum L.), a tall coarse annual, not found in the wild state but thought to be derived from the pre- ceding species. There are many varieties cultivated for various purposes,t the sugar sorghum, or saccharine sor- ghum, for its juice, from which sugar and syrup are ob- tained, the forage sorghum, often called “‘cane”’ on the Great Plains, grown for forage, kafir, grown for forage and the seed, broom-corn for the stiff branches of the inflorescence, and durra, milo, Egyptian corn, etc., for forage and seed. Many other varieties are cultivated in Africa and Asia. In some countries it is called millet. The genus Holcus has been known as Sorghum and has been included by many under Andropogon. The names of the 2 species mentioned appear in books as Sorghum halepense (L.) Pers. or Andropogon halepensis (L.) For a discussion of this sy a see O. Stapf, “Oil Grasses of India and Ceylon” (Kew Bull. Mise. Inf. 8: 1906). +See Ball, ‘‘History and Aidit Nie of Sorghum” (U. S. Dept. Agric. Bur. Pl. Ind. “Bulletin No. 175. 1910). ANDROPOGONEZ i Brot. for the first and Sorghum vulgare Pers. or Andropogon Sorghum (L.) Brot. for the second. H. halepensis L. Johnson-grass. Culms usually 3 to 5 feet tall, erect, smooth, often glaucous, pro- ducing strong creeping rhizomes; sheaths smooth; ligule membra- naceous, about 2 mm. long, the upper half a ciliate fringe; blades smooth or nearly so, somewhat scabrous on the margins, 1 to 3 feet long, mostly 4 to inch wide, tapering to a fine point, the white ny, midrib conspicuous; panicle open ban oy) S and spreading, 6 inches to 2 feet long, usually more or less reddish or purple, the branches 2 to 4 together, naked below, pubescent at the base; spikelets somewhat crowded along the upper part of the branches, in pairs or the termi- nal in 3’s, 1 sessile and fertile and 1 or 2 pediceled and staminate; fertile spikelet about 5 mm. long, - flattened dorsally, elliptical or ovate- lanceolate, indistinctly nerved, firm and coriaceous, at first pubes- cent but later becoming smooth Fria. 17. Holcus halepensis. Inflorescence and rhizomes, X 14, a terminal fertile spike- let with two staminate spikelets, X3. 172 A TEXT-BOOK OF GRASSES and shining on the exposed parts; staminate spikelets more slender, and slightly longer than the sessile, distinctly nerved, membra- naceous, the pedicel about half as long as the sessile spikelet, ciliate. The staminate spikelets disarticulate early so that the mature fertile spikelets show only the 1 or 2 ciliate pedicels at the back. The whole plant is frequently subject to a disease which produces purple spots on the stem and leaves. This is also observed in Holcus Sorghum. 211. Classification of the sorghums.—Ball (loc. cit.) classifies the sorghums as follows: A. Pith juicy. B. Juice abundant and very sweet............ SorGo. BB. Juice scanty, slightly sweet to subacid. c. Panicles cylindrical; peduncles erect; spike- lets 3 to 4 mm. wide; lemmas awnless. . KAFirR. cc. Panicles ovate; peduncle mostly inclined, often recurved; spikelets 4.5 to 6 mm. wide: lemmas Aawhed ..34 6.625 6a es ote Mino. AA. Pith dry. B. Panicle lax, 25 to 70 cm. long... c. Rachis less than one-fifth as long as the panicle; panicle umbelliform, the branches greatly elongated.......:....BRooM-CorRN. cc. Rachis more than two-thirds as long as the panicle. D. Panicle conical, the branches strongly RON eu ue tn eet chars cas x eee ae SHALLU. pp. Panicle oval or obovate, the branches BEES HN 6 erasure ieee 6 KowLiaNG. BB. Panicle compact, 10 to 25 cm. long. c. Spikelets elliptic-oval or obovate, 2.5 to ay HAR es Go bthe aan’ sie KOWLIANG. cc. Spikelets broadly obovate, 4.5 to 6 mm. wide. p. Glumes gray or greenish, not wrinkled, densely pubescent; seeds strongly PRL DONEC adi Mote via Ciirs bs Gabe aie aati DurRRA. DD. Glumes deep brown or black, trans- versely wrinkled, thinly pubescent; seeds slightly fluttenadl aos °i.isoxaeaets MiLo. Sudan-grass resembles Johnson-grass in habit but is an annual, entirely devoid of rootstocks. By Piper it is referred to Sorghum as a variety. Sudan-grass promises ANDROPOGONEA 173 to be of value as a forage crop in the southern states. Tunis-grass, resembling Sudan-grass, is another variety of the sorghum. (See, ““SSome New Grasses for the South,” Yearbook U. 8. Dept. Agr. 1912.) Sorghastrum nutans (L.) Nash, a species of a related genus, is a common constituent of native meadows over the same region that Andropogon furcatus is found. It is a tall slender perennial with bronze-colored panicles with brilliant yellow anthers. Tripe III. NAZIE (ZOYSIE) 212. This is an unimportant tribe of about a dozen small genera. The spikelets are similar to those of Andro- pogonez but having membranaceous awnless instead of hyaline usually awned lemmas, are single or in groups and fall entire from the continuous rachis. In the genera found in the United States the spikelets are in groups. Key To GENERA OF NAZIEX A. Second glume beset with hooked spines....... Nazi. AA. Second glume without hooked spines. B. Groups of spikelets spreading or drooping along one side of the main axis...........ASGOPOGON. BB. Groups of spikelets erect, not secund. Bo Paints SOME oo dg SE kde x's HILARIA. cc. Plants not stoloniferous................. PLEURAPHIS. * The most important genus is Hilaria, with the species H. cenchroides H.B.K. (Fig. 18), curly mesquite. This grass is common on the uplands of Texas and Mexico where it is an important range-grass. It resembles buf- falo-grass in being short, in producing stolons and in forming a sod, and by stockmen is often confused with that grass. In curly mesquite, the spikelets are in clus- ters of 3, the groups borne on the upright axis forming 174 A TEXT-BOOK OF GRASSES Fig. 18. Hilaria cenchroides. Plant reduced; group of spikelets, a staminate spikelet, a pistillate spikelet, X5. (U. S. Dept. Agr., Div. Agrost., Bull. 20.) ' NAZIEHZ—MELINIDE A 175 a short spike. The allied genus Pleuraphis furnishes a few important forage grasses in the Southwest. Pleura- phis Jamesi Torr., is called galleta in New Mexico, a name which is applied in California to P. rigida Thurb. Other grasses of interest belonging to this tribe are Nazia, one species of which, N. aliena (Spreng.) Scribn. extends from the tropics into Arizona, and Osterdamia (Zoysia), one species of which O. matrella (L.) Kuntze (Zoysia pungens Willd.), the Japanese or Korean lawn- grass is occasionally cultivated in California, and along the seacoast of the south Atlantic states. The first mentioned genus is peculiar in that the fascicles of 3 to 5 spikelets form a bur, the second glume of each spikelet being provided with hooked spines. In Osterdamia the spikelets are single instead of in groups. TripeE IV. MELINIDE (TRISTEGINE) 213. This is a small tribe of about 8 genera, none of which is represented in the United States. The spikelets are borne singly in panicled racemes with a continuous axis. The most important genus is Arundinella, reed-like grasses, several species of which are found in tropical America. CHAPTER XVII Trine V. PANICEA SPIKELETS with 1 terminal perfect floret and astaminate or neutral floret below; fertile lemma firmer than the glumes, often chartaceous; spikelets jointed on the pedicel below the glumes. This large and important tribe is, like Andropogonez, found mostly in the tropics and warm regions, but is well represented throughout the United States, especially in the southern portion. The first glume is usually absent in the large genus Paspalum and in a few other genera, and in Reimarochloa and in certain spe- cies of Paspalum the second glume also is absent. In Eriochloa the first glume is reduced to a minute ridge about the swollen ring-like lower joint of the rachilla. In Isachne the lower flower is perfect like the upper. In this tribe the spikelets are usually unawned but the glumes are awned in Echinochloa, Oplismenus and Cheetium, and the lemma in Tricholena. What appear in some genera to be awns are bristle-like branchlets. In Chetochloa there are 1 or more of these below all or some of the spikelets, the bristles remaining after the fall of the spikelets. In Penni- setum there is an involucre of bristles (branchlets) sur- rounding the base of a cluster of spikelets, the bristles being deciduous with the cluster. In Cenchrus the bris- tles are retrorsely barbed and fused into a mass, forming a bur around the spikelets. An Australian genus, Spinifex, is dicecious and Olyra is moneecious. The fruit of Pani- cum and of several other genera is a seed-like body con- (176) PANICEZ 177 sisting of the chartaceous fertile lemma and palea inclos- ing a caryopsis the covering of which is thin. The genus Amphicarpon is peculiar in having 2 kinds of spikelets, ordinary spikelets in a terminal panicle, and underground cleistogamous spikelets borne on short subterranean branches that appear like rhizomes. Only the latter bear seed. Kery To THE GENERA OF PANICEZ A. Spikelets not all alike. B. Spikelets all perfect, but those of the aérial panicle not perfecting grains; the fruitful spikelets cleistogamous, borne on_ sub- terranean branches. Florida to New Jersey. AMPHICARPON. BB. Spikelets not all perfect, the inflorescence bearing pistillate spikelets above and staminate spikelets below; panicles ter- minating the branches; blades _ broad, elliptical. Florida AA. Spikelets all alike. B. Spikelets sunken in the cavities of the PARMENE COPY ARIS So cca oe ae ok Dek STENOTAPHRUM BB. Spikelets not sunken in the rachis. (Par. 223). c. Spikelets subtended or surrounded by 1 to many bristles (sterile branchlets), these distinct or more or less connate, forming an involucre. D. Bristles persistent, spikelets deciduous..CHa#TOCHLOA DD. Bristles falling with the spikelets at (Par. 220). maturity. E. Bristles not united at base, usually slender, often plumose............ PENNISETUM EE. Bristles more or less united into a bur- (Par. 221). feke? AEN, 8 Es SSE wa, CENCHRUS cc. Spikelets not subtended by bristles. (Par. 222). D. Fruit cartilaginous-indurated, not rigid, papillose, usually dark-colored, the lemma with more or less prominent white hyaline margins not inrolled. E. Fruiting lemma _ boat-shaped, the hyaline margins narrow. Florida Sa MRIMANEE o's she kA ee ries ia ANTH/NANTIA EE. Fruiting lemma convex, the hyaline margins broad. F. Fruit lanceolate-acuminate; second glume and sterile lemma long- silky. Florida to Arizona........ VALOTA. 178 A TEXT-BOOK OF GRASSES ‘FF. Fruit elliptic; pubescence short or none. G. Inflorescence of slender racemes, more or less digitately ar- PHOS ES omega Oe eae oe SYNTHERISMA (Par. 216). aa. Inflorescence a capillary panicle..LEPTOLOMA. pp. Fruit indurated, rigid (or if thin, not hyaline-margined). E. Spikelets (or the primary one of a pair) placed with the back of the fruit turned away from the rachis, usually solitary (not in pairs). F. First glume and the rachilla joint forming a swollen ring-like callus below the spikelet.............. ERIOCHLOA. FF, First glume present or wanting but no ring-like callus below the spikelet. Gc. First glume present; racemes racemose along the main axis... BRACHIARIA. ac. First glume wanting; racemes digitate or subdigitate......... AXONOPUS EE. Spikelets placed with the back of the (Par. 215). fruit turned toward the rachis of of the spike-like racemes, or pedicel- late in panicles. F. Fruit long-acuminate, scarcely in- durated; both glumes wanting; spikelets sessile, solitary in spike- like racemes, these reflexed or verticillate at maturity. Florida, Coc SO ae eae y SMI 8s RRP) ela REIMAROCHLOA. FF. Fruit not long-acuminate, indurated. c. First glume typically wanting; spikelets plano-convex, subses- sile in spike-like racemes...... PASPALUM aq. First glume present; spikelets (Par. 214). usually in panicles. H. Glumes and lemmas unawned. 1.Second glume _ inflated-sac- cate, this and the sterile lemma much exceeding the stipitate fruit...........- SACCIOLEPIS. 11. Second glume not inflated- saccate. J. Culms (in our. species) woody; fruit with a tuft of down at apex. Florida.Lastracis. Fia. 19. Paspa- lum _ dilatatum. Inflorescence, x, spikelet, X65. PANICEZ 179 js. Culms herbaceous. PANICUM HH. Glumes or lemmas _ (Par. 217). awned (or awn- tipped in Kchino- chloa colonum). 1. Inflorescence panicu- late; spikelets silky. Introduced oa Po as fe Se TRICHOLEZNA u. Inflorescence of uni- (Par. 219). lateral racemes along a common axis. 3. Glumes 2-lobed, awned from be- tween the lobes; blades broad and thin, lanceolate. Hlonds. 2...» OPLISMENUS. jz. Glumes awned from the tip .. . ECHINOCHLOA (Par. 218). 214. Paspalum L.—A large genus of probably 200 species, well represented in the Gulf and south Atlantic states. It can be easily distinguished by the plano-convex spikelets in spike-like racemes. There are comparatively few species of economic importance. They are almost entirely absent from the grazing regions of the central and western United States, and in the southeastern states do not form an important constituent of grazing areas, being mostly inhabitants of wet or sandy soil and not often gregarious. An attempt was made, but with little success, to intro- duce into cultivation P. dilatatum Poir. (Fig. 19), under the name of water-grass. In the savannas of Central America certain species, such as P. notatum Fligge and P. minus Vasey, are important. 180 A TEXT-BOOK OF GRASSES 215. Axonopus Beauwv—By many authorities this group has been included in the genus Paspalum, but it forms a distinct natural group. Several species are found in tropical America but only Fic. 20. Syntherisma sanguinalis. Plant, «14; two . views of spikelet, 2 extend as far north as the United States. One of these, A. compressus (Swartz) Beauv., is the carpet-grass of the Gulf States, where it is an important grazing-grass and also a lawn-grass. It is a stolonifer- ous perennial with flattened stems, comparatively short, broadly linear, abruptly pointed blades, and slender spikes more or less digitate or clustered at the summit of the stem. (Anastrophus Schrad.) 216. Syntherisma Walt— This distinct group is con- sidered by some to be a sec- tion of Panicum. Perennial or annual: grasses with slender mostly digitate spike-like racemes. The perennial species are natives of the southern United States and southward and are of little importance. Most of the an- nuals are intro- duced from . Europe and are troublesome weeds. One PANICEZ 18] species in particular, S. sanguinalis, is a well-known weed under the name of crab-grass. This and S. ischemum are troublesome weeds in lawns. Being annuals, they die out and leave unsightly brown patches. Crab-grass is often utilized for hay in the southern states. (Digi- taria Hall.) Syntherisma sanguinalis (L.) Dulac. (Fig. 20). Crab-grass. Crop-grass. Annual; culms becoming much branched at base, decumbent or prostrate and rooting at the nodes, the flowering branches ascending, sometimes as much as 3 or 4 feet long; sheaths hirsute, with hairs arising from papilla, sometimes nearly glabrous except near the nodes; ligule about 1 mm. long, thin and membra- naceous, blades flat and thin, more or less hirsute like the sheaths, 2 to 6 inches long and as much as )4 inch wide; panicle consisting of few to several slender spikes, 3 to 6 inches long, a few digitate at the summit of the culm, with usually several others below in a more or less distinct whorl; rachis flat, winged on the margins, about 1 mm. wide, bearing on one side the appressed crowded spikelets, these in pairs, one nearly sessile, the other with a sharply triangular pedicel about half as long as the spikelet; spikelets flattened dor- sally, elliptical-lanceolate, about 3 mm. long, the first glume small, nerveless, about 14 mm. long, the second glume lying next to the axis, narrow, about half as long as the spikelet, appressed-villous, the sterile lemma distinctly 3-nerved, as long as the spikelet, the. lateral nerves more or less ciliate-fringed. The plant is often pur- plish tinged, and the species is variable in size and habit accord- ingly as it grows in rich or poor soil, in the open or among other plants. A related species, S. ischemum (Schreb.) Nash (Digitaria humifusa Pers.; Syntherisma linearis Nash; S. glabrum Schrad.), is common in the eastern United States. This species can be dis- tinguished from the preceding by its being glabrous or nearly so, by the smaller spikelets, and by the absence of the first glume. 217. Panicum L.—This large genus of probably 400 species is distributed throughout all warm regions. The spikelets are usually arranged in panicles. They consist of 182 A TEXT-BOOK OF GRASSES 2 glumes and a sterile lemma, all herbaceous, and 1 indurated fertile lemma and palea. The sterile lmma may contain a staminate flower. The subgenus Dichanthelium, —. . a SS = Fie. 21. Panicum miliaceum. Inflores- | cence, X 24; spikelet and I} fruit (fertile lemma and 7 palea), X7. yh cams confined to America, with its center of dis- tribution in the south- eastern states, includes over 100 species. This group is peculiar in having simple vernal culms with terminal spreading panicles, the vernal phase usu- ally very distinct from the later branched or autumnal phase in which the panicles are much reduced and often included in the sheaths. The autumnal spike- lets are cleistogamous and fertile while the vernal spike- lets appear to be usually unfruitful. Despite the great number of species in the genus Panicum, few are of ecomonic importance. One species, P. miliaceum L. (Fig. 21), proso millet or broom-corn miulet, is culti- vated in Europe for the grain which is used for food, and is sparingly cultivated in this country for fodder. It is #n PANICEE | 183 annual with a drooping panicle. Pard-grass (P. barbinode Trin.), a Brazilian grass much cultivated for forage in the American tropics, is sparingly grown in the southern parts of Florida and Texas. It is a coarse grass, with stolons several feet in length, strongly bearded nodes, and an inflorescence of several spike-like racemes racemosely arranged. Guinea-grass (P. maximum Jacq.) is an African grass, also much grown in the tropics for forage. It is an erect bunch-grass, as much as 8 feet high, with a large spreading panicle. Guinea- grass is too susceptible to frost for culti- vation in the United States except in southern Florida. Texas millet, or Colo- rado-grass, is P. tecanum Buckl., a native of the Colorado River valley in Texas (Par. 62). Panicum bulbosum H. B. K., of the Southwest, produces well-marked corms. - 218. Echinochloa Beauv—A small genus that is included by some as a section of Panicum. The spikelets are as in Panicum, but the sterile lemma and usually the second glume are | awned, often conspicuously so. The fruit is pointed and the palea is free at the summit. The spikelets are in short racemes, these racemosely arranged. All the species are annuals. One species, barnyard-grass, EH. Crus-galla \ (L.) Beauv., is a common weed in Fic. 22. Echinochloa fru- mentacea. Inflorescence, waste places and cultivated soil, A x, spikelet, x5. 184 A TEXT-BOOK OF GRASSES closely allied species, E. frumentacea (Roxb.) Link (Fig. 22), is cultivated for forage under the name billion-dollar- grass. This and EF. colonum (L.) Link are cultivated in India for the seed, which is used for food. 219. Tricholena Schrad—A small genus ‘iy ff of African grasses, one of which has been SY / introduced into the American tropics. S\ iG Spikelets in panicles, very hairy. Tricho- QHY lena rosea Nees has given promise of value WG Zf as a meadow-grass on the dry pine lands WO 7 | of Florida. It is there called Natal-grass 7 and, incorrectly, redtop. Natal-grass is an Se erect perennial, 2 to 3 feet high, with a 4 . loose panicle of pink or rosy silky spike- WE lets. It is said to furnish 4 or 5 cuttings hy of hay in a season. This grass may be grown from seed or by setting out divisions of the root or crown. 220. Chetochloa Scribn—A _ small genus of annuals or perennials, the spike- lets in narrow often spike-like panicles, interspersed with bristles. Two annual European species with cylindrical spike- like panicles are common weeds in the eastern half of the United States. One of them, yellow foxtail, C. lutescens (Weigel) Pele, igi. soumtia- (Fig. 23), has yellow spikes and 5 or chloa lutescens. In~ more bristles below each spikelet; the florescence, xX %4; spikslet with ub~ other, green foxtail, C. viridis (L.) Seribn., has green spikes and only 1 to 3 bristles below each spikelet. Another species, C. italica, closely allied to the latter, is commonly cultivated as millet or Hungarian grass. This has large heads, or spikes, which PANICEZ 185 in some varieties are compound and more or less lobed. In this country millet is grown for forage but in some | parts of the Old World the seed is used for human food. (Setaria AY) SK yes USS « ts J) aie is SN, Beauv.) 1 Chetochloa italica (L.) Scribn. (Setaria italica Beauv. ; Panicum italicum L.) (Figs. 24 and 25). Millet. Foxtail millet. Hungarian grass. Annual; culms erect, simple or nearly so, 2 to 4 feet high, or sometimes larger, glabrous or scabrous below the pani- cle; sheaths glabrous, ciliate on the margins and pubes- cent at the collar; ligule a densely ciliate ring 1 to 2 mm. long; blades flat, sca- brous, narrowed below and toward the apex, 6 to 18 inches long, as_ Fig. 24. Che- much as an inch wide; panicle Neen oe dense, cylindrical, erect or in the Inflorescence, larger forms drooping at the apex, We from an inch or two to as much as a foot in length and from }% inch to 2 inches in diameter, continuous or lobed and interrupted, yellow or purple, bearing bristles as long as the spikelets or much exceeding them; rachis and branches villous; spikelets about 3 mm. long, the bristles from 1 to several times the length of the spikelet, the first glume ovate, 3-nerved, about 1 mm. long, the second glume a little shorter than the spikelet, - cL Se pei 7-nerved, the sterile lemma similar to the second mon millet. Inflor- glume, as long as the spikelet; fruit easily dis- escence, X 4%, fruit . : ; “5. 7 ’ articulating above the sterile lemma, round on one off 4 186 A TEXT-BOOK OF GRASSES side, flattened on the other, straw-colored, red or brown, smooth, very minutely and rather faintly cross-wrinkled. Mi There are many varieties differing in the length and nie color of the bristles, in the color of the seed or fruit and ae in the size and lobing of the panicle or head. The name ate. Hungarian grass is given to the form with small purple g Bo heads. 221. Pennisetum Pers—In this genus the spikelets, single or in groups, are surrounded by bristles as in Cenchrus but the bristles are distinct, and are often unequal in length or — plumose. The inflorescence is a spike or raceme. The most important species of the genus is the pearl millet, P. glaucum (L.) R. Br. (Fig. 26); P. americanum (L.) Schum.; Penicillaria spicata Willd. ; P. typhoideum Rich.). This is a tall coarse annual with ¢ broad blades like sor- ghum and a close cylin- drical spike about a foot long and an inch or less in thickness. At _ maturity the smooth and shining ripened caryopsis bursts through the lemma and palea. Pearl millet is grown in Africa for food and to a limited extent in our southern states for forage. Two species of Pennise- f tum are commonly cultivated for orna- H ment, P. villosum R. Br., with short broad heads and long plumose bristles, and P. Fic. 26. Pen- Auppellii Steud., with more slender rose- nisetum glaucum. Inflorescence, x14. COlored spikes tapering at the apex. spikelet with invo- lucre of bristles, x5. (Penicillaria Willd.; Gymnothriz Beauv.) PANICEH 187 222. Cenchrus L.—Sand-bur. Bur-grass. Low often weedy grasses, usually annuals, the spikelets, singly or 2 or 3. together, inclosed by a bur formed of coalesced bristles or branchlets, these usually retrorsely k barbed. The burs are borne in a spike or raceme, and, detach- ing easily at maturity, are transported by animals. The spikelets remain permanently inclosed in the bur, germination of the seed taking place within it. The first glume is much _ re- duced, sometimes wanting. The com- mon sand-bur of the United States is Cen- chrus carolinianus Walt. (Fig. 27). The one with larger burs found among the sand- dunes of the Atlantic seacoast is C. tribuloides L. 223. Stenotaphrum Trin—The best- known species of this Fic. 27. Cenchrus carolinianus. Upper : portion of plant with inflorescence, X%; genus is the St. — spikelet, x7. 188 A TEXT-BOOK OF GRASSES Augustine grass, S. secundatum (Walt.) Kuntze (Fig. 28), a stoloniferous perennial with flat stems and spikes, the spikelets partly immersed’ in the thickened rachis. This species is grown as a lawn-grass near the seacoast from North Carolina to Florida and Louisiana. Fic. 28. Stenotaphrum secundatum. Upper portion of culms with inflores- cence, X 4, spikelet, X5. CHAPTER XVIII TrisE VI. ORYZEA THIs is one of the smaller tribes, the place of which among the other tribes is not evident. Neither is it in itself a natural group, but is made up of genera of diverse affinities. Certain anomalous genera, such as Pharus (Fig. 29) Streptocheta and Reynaudia, included by Hackel and by Baillon in Oryzez are referred by Bentham and Hooker, the first two to Panicee and the third to Triste- ginee. The articula- tion of the spikelets below the glumes. in- dicates an alliance with the first series of tribes, Panicoidex; the laterally com- Fie. 29. Pharus glaber. Plant reduced; branch- pressed or terete let of inflorescence with a sessile pistillate and pedi- = . = celled staminate spikelet, and a fertile floret, X3. spikelets indicate an (U.S. Dept. Agr. Div. Agrost., Bull. 20). (189) 190 A TEXT-BOOK OF GRASSES alliance with the second series, Porwoidexe. The spikelets are 1-flowered, perfect or unisexual, and usually disposed in panicles. There are usually 6 stamens and the hilum is linear instead of punctiform, in which two respects the structure is somewhat anomalous. The palea is usually described as 1-nerved, but an examination of Oryza sativa shows a palea with the 2 nerves close to the margin, the region between convex instead of concave as is usual in the palea of other grasses. In several genera, glumes are rudimentary or wanting. The tribe includes about 16 genera, mostly inhabitants of tropical America, 6 extending into the United States. KEY TO THE GENERA OF ORYZEX A. Spikelets perfect, strongly pee es B. Glumes 2; lemma often awned .... . .OryzA(Par.224) BB. Glumes wanting; lemma awnless...... . HOMALOCEN- AA. Spikelets unisexual, terete; plants moncecious. CHRUS. B. Plants slender, creeping in the mud or floating in the water. c. Inflorescence a few-flowered spike; plants not stoloniferous. Southeastern United BG ae ca On Soa ie Gs Oe a ee HyYDROCHLOA. cc. Inflorescence a panicle; plants stolonifer- ous. Alabama...... bak Era ctaca'als, eee LuziIoua. BB. Plants erect, stout; marsh plants or ter- restrial. c. Blades elliptical or oblanceolate, petiolate; fruit cylindrical, beset with hooked hairs; plants terrestrial. Florida....... PHARUS. cc. Blades elongated, linear, not petiolate; marsh plants. D. Pistillate spikelets in the usually narrow upper part of the panicle; staminate spikelets in the spreading lower part. .ZIZANIA pp. Pistillate and staminate spikelets mixed (Par. 225). in the panicle, the former below and the latter above on each branch. Cet FSGS inte aoe ie ZIZANIOPSIS. 224. Oryza L—Rice. Characterized by the perfect flowers, strongly compressed spikelets and the presence ORYZEZ 191 of 2 small glumes. Of the half-dozen species only one is of importance. This is O. sativa L. (Fig. 30), the cultivated rice, an annual now erown in numerous varieties throughout the warmer regions of the world. f Rice is the most important of the cereals in the sense that it furnishes food to more people | than any other one grain. The allied genus Homalocenchrus is represented by several perennial species in the eastern United States. The spikelets resem- ble those of Oryza but are smaller and lack the glumes. , 225. Zizania L—Indian rice. Water-rice. Tall marsh-grasses, with large panicles, usually growing in shallow water in large =\\\bi) areas. The pistillatespike- _ lets are long-awned and Bites erect, the staminate are ¢ Ze AN awnless and drooping. 3 Zp MS \ The seeds were formerly ail Fig. 30. Oryza sa- tiva. Inflorescence, gathered by the American 1p x 4, spikelet, X3. : Indians and used for food. There are 3 species, Zizania palustris L. (Fig. 31), the common Indian rice of the ere ° . G. . 1zanla United States, Z. aquatica L., a less com- palustris Inflores- ence, muc re- mon species of Canada, and Z. latifolia duced. (U. 8. Dept. . Agr., Div. Agrost., (Turez.) Stapf, of eastern Asia. Bull. 14.) CHAPTER XIX TrisE VII. PHALARIDEA ——) A SMALL tribe of about 6 genera in the YY cooler parts of the northern hemisphere and NW Y of Australasia. Spikelets with 1 fertile (N WH iy * floret and a pair of staminate or neutral Wi J UZ, florets below. In Phalaris, the pair of sterile Re Jp \ < . \ SS ZZ. florets appear as small scales within the SW ‘y ZZ glumes. In Savastana the lateral florets (1 WZ or 2) are staminate and as large as the NI-Z : ° Ni i [AA fertile floret. Only 3 genera are found in , VEZ the United States. G7 - 7 j Key To THE GENERA OF PHALARIDEE A. Lateral florets stami- RES eo ed ea SAVASTANA AA. Lateral floretsneutral. (Par. 226). B. Lateral florets re- duced to small awn- less scales; spikelets much compressed ee ere PHALARIS BB. Lateral florets con- (Par. 228). sisting of awned hairy sterile lemmas about as long as the fertile floret; spike- lets terete......... ANTHOXAN- [THUM (Par. 227). 226. Savastana Schrank.— Yi LZ bi << we Fic. 32. Anthoxanthum odora- tum. Inflorescence, 1; spikelet, Inflorescence an open or con- the two sterile | d th , fertile floret, XS. Sstracted but not spike-like (192) PHALARIDEZ panicle; spikelets brown and shining; lateral Wy florets (often awned) with 3 stamens, the i) central perfect floret with 2 stamens. The W\y best known species is S. odorata (L.) Scribn., & WA WY or vanilla-grass, a native of northern Europe Ni; and America. The name vanilla-grass refers \ Wi to the fragrant odor of the foliage. Fragrant NH baskets, boxes and mats are woven of the Wy long leaves of the sterile shoots, by the American Indians. Commonly called holy-grass in Europe. (Hierochloé R. Br.) 227. Anthoxanthum L.—lInflores- cence a bronze-green spike-like panicle. One species, A. odoratum (Fig. 32), sweet vernal grass, a native of Europe, introduced in the cooler parts of the United States. Like vanilla-grass, it is fragrant, for which reason it is sometimes cultivated as a constitu- ent of meadow-grasses to impart a pleasant odor to the hay. Sweet ver- nal grass is useless as a forage-grass. A. aristatum Boiss. (A. Puelii Lecog & Lamotte), an annual species is sometimes cultivated in the west and southwest. Anthoxzanthum odoratum L. Sweet vernal grass. Perennial; culms in tufts, without rhizomes, erect, slender, smooth, 1 to 2 feet high; sheaths smooth or somewhat pubescent; ligule membranaceous, 2 to 5 mm. long; blades flat, thin, scabrous, 1 to 3 inches long, M 193 Fic. 33. Phalaris arun- dinacea. Inflorescence, x 4; spikelet and fertile floret, X65. 194 A TEXT-BOOK OF GRASSES mostly basal, one about the middle of the culm, the upper portion of the culm naked; panicle dense, spike-like, bronze-green, 1 to 3 inches long, narrowed above and below, the short branches spread- ing in flower; spikelets 8 to 10 mm. long, lanceolate, acuminate, the glumes sparsely pilose, acuminate, the first membranaceous, about half as long as the somewhat indurated second glume, the first sterile lemma short-awned below the apex, the second bearing Fig. 34. Phalaris canari- ensis. Inflorescence, xX %; glumes and fertile floret with the pair of sterile lemmas, X5. a strong bent scarcely exserted awn near its base, both exceeding the chestnut- brown, smooth and shining fertile lemma and palea. Common in grassland in the northeastern states. 228. Phalaris 1 —Inflorescence a short or long usually dense spike- like panicle. The spike is often white or variegated with green from the green nerves of the spikelets, and is usually papery at maturity. One of our native species, P. arundinacea L. (Fig. 33), reed canary-grass, is a perennial found in the northern portion of the United States, where it furnishes an excellent quality of wild hay. In this species the sterile lemmas are much reduced and are closely appressed to the fertile lemma and palea. A variety of this (var. picta L.) with leaves striped with white is cultivated for ornament under the name of ribbon-grass or gardener’s garters. P. carolinianus Walt., a perennial of the southern United States, is cultivated to a limited extent for winter forage. Another species, P. canariensis L., els PHALARIDEA 195 canary-grass, an annual with ovate heads, is an occasional weed introduced from Europe. This is grown in Europe for the seed which furnishes the canary seed of commerce. Canary seed usually contains also the seed of Panicum miliaceum. The seed of Phalaris canariensis (Fig. 34) is pale yel- low, 5 mm. long, elliptical-lanceolate, laterally somewhat flattened but equally convex on both sides, hard and shining and more or less pubescent. The fruit of Panicum miliaceum is pale, brownish or reddish, about as long as canary-grass seed but much more plump, dorsally flattened on one side, the palea being inclosed or overlapped by the lemma, the whole smooth, hard, shining, and faintly nerved. The seed, when removed from the inclosing lemma and palea is nearly white, somewhat globular with a notch in one side, pearly in appearance. The fruit of common or foxtail millet (Chztochloa italica) differs from that of Panicum miliaceum in being some- what smaller and faintly cross-wrinkled, and in the appearance of the palea, which presents 2 ridges near the margin representing the 2 keels. (See Figs. 21 and 25.) CHAPTER XX Tripe VIII. AGROSTIDEA A LARGE tribe of about 50 genera inhabiting more especially the temperate and cooler regions of the world. Spikelets 1-flowered (the rachilla prolonged as a stipe behind the palea in a few genera) usually perfect, arranged in open, contracted or spike-like panicles, but not in 1-sided spikes or racemes. The spikelets are jointed with the pedicel in a few genera, and fall off entire (Alopecurus, Cinna, Polypogon, Lycurus, Limnodea). The palea is usually 2-nerved but in Cinna it appears to be 1-nerved, the 2 nerves lying close together. In some species of Agrostis the palea is a small nerveless scale or is wanting. In some genera the floret is raised slightly from the glumes on a hard stipe, the short internode of the rachilla.” This remains attached to the floret at maturity as a hard point and is called the callus.. This callus is pronounced in Stipa and Aristida and less so in Oryzopsis, Muhlen- bergia and a few other genera. In some species of Calama- grostis the short callus bears numerous silky hairs as long as the floret. KeryY TO THE GENERA OF AGROSTIDEZ a. Lemma indurated at maturity, firmer than the glumes, closely enveloping the caryopsis and usually the palea, awned (except in Milium) from the tip, or mucronate (some speeies of Muhlenbergia). sp. Awn trifid (the lateral awns sometimes short, rarely wanting)..................-ARISTIDA Be. Awn simple. (Par. 229). (196) AGROSTIDEZ 197 c. Spikelets in pairs in a spike-like panicle; one perfect, the other staminate or neu- tral, the pair deciduous together....... Lycurus. cc. Spikelets all alike. D. Rachilla prolonged behind the palea as a pedicel; glumes very short; inflo- rescence a narrow few-flowered panicle. BRACHYELY- pp. Rachilla not prolonged. [TRUM. E. Lemma awnless; fruit short, ovoid; inflorescence an open panicle... Miro. EE. Lemma awned or mucronate. F. Awn slender, straight or flexuous, not twisted nor bent; spikelets small; glumes shorter than the PER, Ee ee nd ee oe MUHLEN- FF. Awn usually stout, bent or twisted. [BERGIA. c. Awn stout, twisted and bent, (Par. 231). persistent; callus pointed, long; Iemana- narvow... 2.4 V4. tee ne STIPA cc. Awn bent but not twisted, de- (Par. 230). ciduous; callus short; obtuse; lemma broad, elliptical or GUE C eco sts wcn Oe ae ae ORYZOPSIS. AA. “ae not indurated at maturity, mem- branaceous or hyaline, like the glumes or more delicate. B. Glumes none; low annual. Oregon and ARNE DE 0 88 en the cee ome ate b ScHMIDTIA. BB. Glumes present. c. Glumes falling with the spikelet, some- times with a portion of the pedicel or branchlet, the articulation being below the glumes (compare Cinna). p. Glumes long-awned................... POLYPOGON. pp. Glumes awnless. E. Inflorescence a dense spike-like pan- icle; lemma awned from the lower part of the back.. ae . ALOPECURUS EE. Inflorescence a narrow loose panicle; (Par. 233). lemma awned from the bifid apex. LIMNODEA. cc. Glumes persistent, not articulated on the pedicel. p. Glumes longer than the lemma. E. Glumes plumose; an annual with woolly ovoid heads............... LAGURUS EE. Glumes not plumose. (Par. 237). F. Inflorescence a dense cylindrical spike-like panicle; glumes com- pressed-carinate, ciliate on the (Par. 232). keels; lemma awnless........... PHLEUM 198 A TEXT-BOOK OF GRASSES FF. Inflorescence an open or contracted but not densely cylindrical pan- icle; glumes not compressed- carinate and ciliate. Gc. Glumes saccate at base; lemma long-awned; inflorescence con- tracted, shining; annuals..... GASTRIDIUM. aa. Glumes not saccate at base. H. Lemma bearing an awn several times its length; annuals with open panicles.......... APERA. HH. Lemma short-awned, or awn- less, the palea often reduced Ge weir. (gece. cece AGROSTIS pp. Glumes as long as, or shorter than the (Par. 234). lemma. E. Lemma bearing a tuft of hairs at base from the short callus. F. Lemma and palea thin............ CALAMAGROSTIS FF. Lemma and palea chartaceous. (Par. 235). G. Panicles spike-like; rachilla pro- IGM eee Oe ee ee AMMOPHILA ac. Panicles open; rachilla not pro- (Par. 236). RS Se tootsie ce ho CALAMOVILFA. EE. Lemma without hairs at base. F. Palea apparently 1-nerved, the 2 nerves close together; rachilla prolonged; panicle open......... CINNA. FF. Palea distinctly 2-nerved; rachilla not prolonged. c. Nerves of lemma densely silky.. BLEPHARO- aa. Nerves of lemma not silky. [NEURON. H Fruit not inclosed in the lemma and palea, seed usually also loose in the pericarp, this opening at maturity... .SPOROBOLUS. HH. Fruit inclosed in the lemma and palea; the seed also inclosed in the pericarp at maturity and grown to it; panicles spike-like in our species. 1. Panicles short, partly in- closed in the upper sheath; sparingly introduced from ine Old. Wortd.... 52.5.5 HELEOCHLOA, m1. Panicles elongated; tall per- ennials of Arizona and southward.......... +:+++lPICAMPES. AGROSTIDEZ 199 229. Aristida L—Needle-grass. A large genus, mostly tufted perennials of the warmer parts of the world, especially abundant in America. They are easily dis- tinguished by the narrow terete lemma bearing a pointed hairy callus below and a trifid awn above. The 2 lateral awns are sometimes shorter than the others or may be absent altogether (A. scabra (H.B.K.) Kunth and its allies). The species not only have little forage value but on the contrary are often troublesome to ranchmen because of the sharp fruits which penetrate the skin of grazing animals. Sev- eral low perennial species are found in the new soil around the burrows of prairie dogs, hence the name dog-town grass. 230. Stipa L.— Spear-grass. A large genus of tufted per- ennials found on the ; Fie. 35. Aristida longiseta. plains and f steppes Spikelet, the floret raised from of both hemispheres. the glumes, X1. The fruit resembles that of Aristida but terminates in a single 200 A TEXT-BOOK OF GRASSES awn. This awn is usually tightly twisted below, the upper part being once or twice bent. In some species (S. spartea Trin.) (Fig. 36) the awn is stout and several inches long; in others it is beautifully plumose with silky hairs (S. pennata L. of the Russian steppes and S. speciosa Trin. & Rupr. of California). The vari- ous species form an important part of the forage on the plains and foothills of the south- western states and Mexico. The esparto- or alfa-grass of Spain and Algeria (S. tenacissima L.) furnishes a fiber that is used for paper and for cordage. The sleepy- grass (S. Vaseyi Seribn.) of Colorado and New Mexico because of narcotic qualities is injurious to horses. Two species of the Old World are said to be poisonous (S. inebrians Hance and S. sibirica Lam.). 231. Muhlenbergia Schreb—A large genus of mostly American grasses, especially abundant on the dry uplands of the southwestern states and Mexico. It grades on the one hand into Sporobolus, from which it differs in having an awned or mucronate lemma, and on the other into Epicampes, from which it differs in having a relatively firmer lemma. Many species are important constituents of the forage upon grazing areas in the Southwest. One species of the allied genus Fic. 36. Stipa spartea. Mature floret (fruit) with_ twisted awn, X1 201 AGROSTIDEZ Fic. 37. Muhlenbergia gracilis. Plant, X 14; spikelet, the floret raised from the glumes, glumes and floret, X5. Bull. 26.) (U. S. Dept. Agr., Div. Bot., 202 A TEXT-BOOK OF GRASSES Epicampes (EF. rigens Benth.) is of some economic im- portance in Mexico, whence it is exported, the strong fibrous roots being used to make coarse brushes. 232. Phleum L—Timothy. A _ small genus of cold regions, recognized by the densely cylindrical spike-like panicles, and 1-flowered much-compressed spikelets., Only 1 species is native in America, the moun- tain timothy (P. alpinum L.) of the higher mountains and arctic regions. Common timothy (P. pratense L.) (Fig. 38), a native of Europe, is our most important cultivated meadow-grass. In some localities this grass is known as herd’s-grass. Phleum pratense L. Timothy. Perennial; culms in tufts, somewhat bulbous at base, erect, smooth, 2 to 3 feet high; sheaths smooth; ligule membranace-- ous, 2 to 3 mm. long or the uppermost longer; blades flat, a few inches to a foot long; panicle densely cylindrical and spike-like, 2 to 5 inches long, obtuse; glumes about 3 mm. long, excluding the 1 to 2 mm. long awn, compressed, abruptly rounded to the awn, long-ciliate on the keel, the lemma and palea about equal, thin, half as long as the glumes. ey 233. Alopecurus L—A small NS genus of wide distribution, in cold tem- )Y\SSS) perate regions and in high altitudes, Fic. 38. Phleum pra~ one species of which, meadow foxtail tense. Inflorescence, X 14; 4 ; : eS ee (A. pratensis), a native of Europe, is . occasionally cultivated as a meadow- grass. This species may be recognized by its resemblance to timothy in having densely cylindrical spike-like panicles, but differing in having awns on the back of — AGROSTIDEZ 203 the lemmas that protrude from the spikelets giving the spike a soft furry appearance. Alopecurus pratensis L. (Fig. 39). Meadow foxtail. Perennial; culms erect from a short creeping base, smooth, 1 to 3 feet high; sheaths smooth, the uppermost somewhat inflated; ligule membra- naceous, truncate, 2 to 4 mm. long; blades flat, smooth beneath, rough above, 2 to 6 inches long; panicle dense, cylindrical, 114 to 3 inches long, ¥% inch thick; glumes 5 mm. long, equal, awn- less, 3-nerved, ciliate on the keel, connate at base, the broad, obtuse 5-nerved lemma nearly as long, bearing from near the base a slender dorsal slightly bent awn, exserted about_5 mm. 234. Agrostis L.—Bent- grass. A large genus found all over the world but sparsely represented in tropi- cal America. The North American species are nearly all perennials and are especi- ally abundant in the western mountains. Spikelets 1-flow- ered; lemma delicate, shorter than the nearly equal glumes, Fia. 39. Alopecurus pratensis. Plant often awned from the back; reduced; spikelet and floret, x3. (U.S. - a Dept. Agr., Div. Agrost., Bull. 20.) palea small or wanting; in- florescence an open or contracted panicle. The wild species are mostly important constituents of grazing areas in the mountains. Redtop (A. alba), cultivated as a meadow- grass, is a perennial 1 to 4 feet tall, with rootstocks, flat 204 A TEXT-BOOK OF GRASSES blades and an erect~open often reddish panicle usually 4 to 8 inches long, with verticillate lower branches. A smaller form, Rhode Island bent (A. alba vulgaris), with finer foliage and a smaller more open panicle, is often used for lawns. Another form of Agrostis alba with creeping stems and narrow panicle is used for lawns under the name of creeping bent. Agrostis alba L. (Fig. 40) Redtop. Peren- nial; culms erect from a more or less decum- bent base bearing rhizomes, smooth, 1 to 4 feet Ve high; sheaths smooth; ligule membranaceous, b ‘i J y pointed, more or less lacerate, as much as 6 .% ¥ 1, mm. long; blades flat, 2 inches to as much as ys y, a foot long, scabrous on both surfaces, strongly \ \p Bp nerved, acuminate, usually rather stiffly up- Sy Ae, right; panicle 2 to 12 inches long, open at ( Nv Va Ky anthesis but usually more or less contracted Vi Ca Ae A , ; Sky \ ag Vi <5 in fruit, the branches in whorls, some naked NIE, below, others short and _ spikelet-bearing at base; glumes 2 to 3 mm. long, lanceolate, pointed, scabrous on the keel, the lemma thin, a little shorter than the glumes, the palea half to two-thirds as long as the lemma. The color of the panicle varies from greenish to purple or brown. This grass has escaped from cultiva- tion or has been introduced over a large part of the United States. In the western mountains the species is doubtfully native. This grass is known by the name of herd’s-grass in some localities, especially in Pennsylvania. In Eng- land it is called fiorin. Agrostis alba vulgaris (With.) Thurb. Rhode Island bent. Differs from the preceding in the smaller size, more delicate culms and foliage, smaller and especially more open and fewer-flowered panicle, Fic. 40. Agrostis alba. Inflorescence and z “ rhizomes, X14; spikelet, X5. this not contracted in AGROSTIDEZ 205 fruit. The ligule is often shorter and usually truncate. This form is common in grass land in the northeastern states, where it is introduced or escaped from cul- tivation. Agrostis alba maritima (Lam.) G. F. W. Mey. Creep- ing bent. Differs from redtop in its creeping or stoloniferous stems and narrow panicles, the blades mostly short and ap- pressed. Native along the North Atlantic coast of America and Europe, and the Pacific coast from central California to British Columbia. The form cultivated for lawns appears to have been derived from this. Rhode Island bent. In botanical literature this name has been applied to Agrostis canina L., a grass similar in appearance to A. alba vulgaris, but usually more delicate, the glumes about 2 mm. long, the lemma about three-fourths as long as the glumes, bearing a little below the middle a bent exserted awn, the palea wanting. This is a native of Europe and is rare in America. There is no evidence that this species has been cultivated in Europe or America. The seed sold under the name Rhode Island bent is Fic. 41. Calamagrostis scabra. Plant reduced; spikelet, the floret raised from the glumes, 3. (U. S. Dept. Agr., Div. Agrost., Bull. 20.) imported from Europe, and consists for the most part of some form of Agrostis alba, usually of creeping bent, or the form described above under A. alba vulgaris. 235. Calamagrostis Adans—A large genus of peren- nials growing in the cooler regions of all continents. 206 A TEXT-BOOK OF GRASSES Spikelets 1-flowered, the rachilla prolonged; lemma awned from the back, surrounded by a tuft of callus hairs; inflo- rescence an open or contracted panicle. A common con- stituent of native meadows in the northern temperate and Fig. 42. Ammophila arenaria. Inflorescence and lower portion of plant, x 4%. (U. S. Dept. Agr., Div. Agrost., Bull. No. 14.) arctic regions of America. Bluejoint, C. canadensis (Michx.) Beauv., is com- monly cut for hay from Montana to Minnesota. Thisis a perennial with creeping rhizomes, erect culms 3 to 5 feet high and a rather open panicle resembling that of redtop. Another species, pine-grass C’. rubescens Buckl. (C. Suksdorfii Secribn.), is an excellent range-grass in the mountains of eastern Oregon and Washington. Calamagrostis scabra Presl (erroneously referred to C. Langsdorfit) (Fig. 41) is a common grass along the coast of Alaska and in open grass lands of British Columbia. 236. Ammophila Host—Beach- grass. Marram-grass. A genus of 1 or 2 species, allied to Calamagrostis from which it differs in its strongly com- pressed spikelets and _ chartaceous lemma and palea, the lemma awnless. The common species is A. arenaria (L.) Link (Fig. 42), which grows in sand- dunes of the north Atlantic coast of Europe and America. It is found also on the sand-dunes along the east and south shores of Lake Michigan. It produces extensively creeping root- stocks because of which, and because AGROSTIDEHA 207 the culms are able to push upward when buried, it can grow in drifting sand. It has been utilized as a sand- binder in Europe and more recently in America, especially on Cape Cod and in Golden Gate Park, San Francisco. In Europe marram-grass is used also for paper-making. 237. Lagurus L—The one species, L. ovatus L., a native of Europe, is cultivated as an ornamental grass for dry bouquets. It is an annual with ovoid woolly heads, and narrow pointed plumose glumes. CHAPTER XXI TrispE IX. AVENEA A MODERATELY large tribe of about 30 genera, found in the cooler parts of the world. Spikelets 2- to several- flowered, in open or contracted panicles or sometimes in racemes; lemmas usually shorter than the glumes, usually awned on the back or from between the teeth of a bifid apex, the awn bent and often twisted, the callus and usually the rachilla-joints hairy. Only a few of the genera are found in America. In all these except Aira, an intro- duced genus, there is a prolongation of the rachilla behind the uppermost floret; and except in some species of Spheno- pholis and in the American species of Koeleria the lemma is awned. These genera are usually placed in Festucee, but in all characters except the absence of the awn they show affinity with the genera of Avenez. Key To GENERA OF AVENE A. Articulation below the glumes, these deciduous with the whole or a part of the spikelet. B. Glumes longer than the 2 florets, pubescent.. NoTHOLCUS BB. Glumes shorter than the 2 or 3 florets, (Par. 238). glabrous or scabrous, the second widened Ee a Bia SG SO hd a eel a Sig SPHENOPHOLIS. AA. Articulation above the glumes and between the florets. B. Lemma awnless or mucronate; inflorescence a spike-like panicle; an erect perennial.... K@LERIA. BB. Lemma awned. c. Rachilla not prolonged; spikelets 2-flow- ered; delicate introduced annuals....... AIRA. ce. ero prolonged behind the uppermost oret. (208) AVENE 209 p. Awn arising from between the teeth of the bifid apex, flattened, twisted; in- florescence a simple panicle or reduced to araceme or even to a single spikelet. DANTHONIA. pp. Awn dorsal. ~ E. Lower floret of the 2-flowered spike- JGh: Shar AAG jG eh 2 ces eo oe . ARRHENATH- EE. Lower floret perfect. [ERUM (Par. 241). F. Spikelets large, the glumes over Dery tntipe Se se Oey a ots ea oe AVENA FF. Spikelets less than 1 cm. long. (Par. 239). G. Lemma keeled, bidentate; awn arising from above the middle..TRIsETUM. eq. Lemma convex; awn from below ; UES EERIE Fs ec ne ee Se DESCHAMPSIA. 238. Notholcus Nash—A genus of several species of Europe and Africa, one of which, velvet-grass (NV. lanatus), is introduced in America. This is sometimes cultivated as a meadow-grass but has little forage value. As it thrives better than other meadow-grasses upon poor soil it is utilized for sterile ground. It has escaped in many parts of the United States especially on the Pacific coast. Velvet- grass is an erect perennial with velvety foliage and a narrow panicle, expanded in flower. (Holcus L. in part.) Notholcus lanatus (L.) Nash. (Fig. 43), Velvet-grass. Perennial; culms erect, 1 to 3 feet high, pubescent; sheaths velvety especially near the node; ligule pubescent, membranaceous, about 2 mm. long, more or less toothed and ciliate; blades flat, velvety, mostly 2 to 4 inches long; panicle oblong, 2 to 4 inches long, pale or purplish, in flower spreading and rather open, in fruit contracted; spikelets 4 to 5 mm. long, the glumes pubescent, longer than the florets, ciliate on the nerves, the upper broader, 3-nerved, the awn of the second floret hooked. A common weed from Puget Sound to San Francisco, in moist and dry soil. 239. Avena L—Oats. Mostly annuals with large spikelets, of which the common cultivated oat (A. sativa) is the most familiar example. The drooping spikelets are in open panicles. The large and papery glumes are longer than N 210 A TEXT-BOOK OF GRASSES the lemmas, the latter being awnless or bearing a straight awn. A wild species (A. fatua) differs in having the lemma covered with brown hairs and in having a stout geniculate twisted dorsal awn attached near the base. This species is a native of Europe but is introduced on the Pacific coast where it is a common weed known as wild oats and where it is often used for hay. Uh | fees fee / WYP Mog EB MBE vi SS —, ANS eh NSS Avena sativa L. Cultivated oat. An- nual; culms erect, tufted, smooth, 2 to 4 feet high; sheaths smooth, striate, the lower rather papery; ligule membranace- ous, truncate, 1 to 3 mm. long, toothed or serrate, decurrent along the margin of the sheath; blades flat, as much as 1 foot long and 1% inch wide, scabrous especially on the margins; panicle open or more or less contracted, erect or nodding, some- times 1-sided, the pedicels thickened at the apex; spikelets large, drooping, vari- NW: War 2 able in size but usually about 34 to 1 inch long, MY i the glumes strongly several-nerved, membra- J y at naceous, acuminate, scabrous, containing usually 2 florets, the lemmas smooth or slightly hairy at the base, the teeth acute but not awned, the RS Vy , : \ SUZ i £= dorsal awn absent or, if present, usually straight A AW Za NR and not much exceeding the glumes, often pre- Ney : \\ AS WW sent only on the lower floret, the palea inclosed RWVE ; by the inrolled margin of the lemma, densely Fie. 43. Notholcus lanatus. Inflorescence, X 24; spikelet, the two florets raised from the glumes, X7. short-ciliate on the 2 keels. The florets do not easily disarticulate, a condition probably due to cultivation. Commonly cultivated and often escaped from fields and in the vicinity of elevators, mills, railroads and in waste places, but rarely established’ permanently. There are sev- eral races or possibly species in cultiva- tion. The naked oat (A. nuda L.) differs in having more than 2 florets and in AVENE 211 having the caryopsis loosely and not permanently inclosed in the nerved lemma. Avena fatua L. (Fig. 44). Wild oats. Differs from A. sativa chiefly in the spikelet characters. Florets easily disarticulating, the lemma beset with stiff usually brown hairs, these more abundant at base, the teeth acute as in A. sativa, the dorsal awn well developed, over an inch long, geniculate, twisted at base, usually brown. A common weed on the Pacific coast and occasional elsewhere. Avena fatua glabrata Peterm. Differs from A. fatwa in having nearly or quite gla- - brous lemmas. This form can be distinguished from the usual forms of A. sativa by the strong awn and by the easily disarticulating spikelets. Avena barbata Brot. Differs from A. fatwa in having more slender panicle branches and in the awned teeth of the lemma. A common weed on Fic. 44. Avena the Pacific coast, and a constituent of the wild fatua. Spikeletand oats of that region. alge Raa Avena sterilis L. Animated oats. Differs from A. fatua in having larger spikelets, the glumes nearly 2 inches long, and awns about 2 inches long. An occasional weed and some- times cultivated as a curiosity, the “seeds’’ moving about as the awns twist and untwist. This motion is due to the absorption or loss of moisture. 240. Origin of the cultivated oats—Trabut has shown that our cultivated oats are derived from at least three wild species. Avena fatua is the parent of most of the varieties cultivated in America, and in general the va- rieties of temperate and mountain regions. The Algerian oat grown in North Africa and Italy is derived from Avena sterilis. A few varieties such as Avena strigosa, adapted to dry countries, are descended from Avena 212 A TEXT-BOOK OF GRASSES barbata. (See Translation of Trabut’s article in Journal of Heredity 5: 56. 1914.) 241. Arrhenatherum Beaw.—To this small genus belongs the tall oat-grass (A. elatius), a tall perennial with narrow pani- cles of spikelets similar to those of the oat but smaller, about 8 mm. long, 2-flowered, the first floret staminate and awned, the second perfect and nearly awnless. This is a native of Europe and now cultivated occasionally in this country as a meadow- grass, especially in mixtures. It is also called Randall-grass. Arrhenatherum elatius (L.) Beauv. (Fig. 45.) Tall oat-grass. Perennial; culms erect, smooth, 3 to 4 feet high, sheaths smooth; ligule membranaceous, truncate, about 1 mm. long; blades narrow, usually not over 4 inch wide, scabrous on both surfaces; panicle long and narrow, rather loose, 6 to 10 inches long, pale or purplish, shining, the short branches verticillate, usually spikelet-bearing from the base; spikelets 7 to 8 mm. long, the glumes minutely sca- brous, unequal, the second nearly as long as the florets; lemmas scabrous, the awn of the staminate floret about twice the length of its lemma, geniculate, sca- brous. Often escaped from cultivation and a weed in waste places in the humid region. Arrhenatherum elatius bulbosum (Presl) Koch. Differs from the preceding in pro- ducing corms at the base of the stems. These corms are 5 to 10 mm. in diameter in clusters of usually 2 to 5 in moniliform Fig. 45. Arrhenatherum strings. An occasional introduction, from elatius. Inflorescence, K 4%; spikelet, 4. Virginia southward. CHAPTER XXII TripBE X. CHLORIDE A MODERATELY large tribe of about 30 genera, mostly of warm regions. It can be recognized by its 1-sided spikes or spike-like racemes, the spikelets borne in 2 rows on one side of a continuous rachis. Spikelets 1- to many- flowered, usually articulated above the glumes. The spike is reduced to 2 or 3 spikelets or even to 1 spikelet in some species of Bouteloua and allied genera. In the dicecious genus Bulbilis the pistillate spikelets are in a small cluster among the leaves, but the staminate inflo- rescence is characteristic of the tribe. Some species of Leptochloa approach the tribe Festucez, the spikes not being strictly 1-sided. In some species of Bouteloua the small spikes are deciduous from the main axis, thus resem- bling Naziez. KEY TO THE GENERA OF CHLORIDEX A. Plants dicecious or monecious; low stolo- SET WTT DETER oo si. bowen Eee ce BULBILIS AA. Plants with perfect flowers. (Par. 245). B. Spikelets with more than 1 perfect floret. c. Spikes solitary, the spikelets distant, ap- pressed, several-flowered; a low per- Pee shin Dorey ae pares Wee iL war MEO TRIPOGON. cc. Spikes more than 1 (exceptionally 1 in Eleusine). Dp. Spikes numerous, slender, along an RAGE CENIG ds os ete tok LEPTOCHLOA. DD. Spikes few, digitate or nearly so; annual weeds. E. Rachis of spike extending beyond the [TENIUM. WUBICRBB ENS do octal ais WS ais be MRO DacTYLoc- 214 A TEXT-BOOK OF GRASSES EE. Rachis not prolonged. . . ELEUSINE. BB. Spikelets with only 1 perfect floret, often with additional imperfect or modified florets above, sometimes also below. c. Spikelets without additional modified florets, the rachilla sometimes prolonged. p. Rachilla articulated below the fit E. Glumes narrow, unequal. . . SPARTINA. EE. Glumes equal, broad and _ boat- RR eh es hice el a oe te, BECKMANNIA. DD. Rachilla articulated above the glumes. E. Spikes digitate; plants extensively CEEERENEM Sisas oa Cckte we fa eee CAPRIOLA ; (Par. 242). EE. Spikes racemose; plants cespitose.. . .SCHEDONNARDUS cc. Spikelets with 1 or more modified florets above the perfect one. D. Spikelets with 2 sterile florets below the RCC aise Sc. hoe as sk atte CAMPULOSUS. DD. Spikelets with no sterile florets below the perfect one. E. Spikes digitate. F. Fertile lemma 1-awned or awnless..CHLORIS (Par. 243). FF. Fertile lemma 3-awned........... TRICHLORIS. EE. Spikes racemose. F. Spikelets distant; spikes slender....GyMNOPOGON. FF. Spikelets approximate, often im- bricated. G. Spikes usually short and es stout, sometimes with only 1 to few Le ec en BoUTELOUA (Par. 244). 242. Capriola Adans—A small genus of Old World grasses, one of which, Bermuda-grass (C. Dactylon), has been introduced in America and is now common in the tropics and warmer regions as far north as Maryland and southern Kansas. This is a low perennial, producing extensively creeping stolons and rhizomes and erect flower- culms, a few inches to a foot or more in height, ending in 3 to 6 slender digitate spikes. It is an excellent grass for lawns and pastures in the southern states but in cultivated fields often becomes a troublesome weed. In soft soil it CHLORIDEZ 215 forms large rhizomes and coarse foliage but in lawns the foliage is fine and the plants are stoloniferous. Although called Bermuda-grass it is not a native of Bermuda. (Cynodon Rich.) Capriola Dactylon (L.) Kuntze (Cynodon Dactylon (L.) Pers.). (Fig. 46.) Bermuda-grass. A gray-green perennial; culms exten- sively creeping, either below the surface of the soil forming rhi- zomes, or above ground forming stolons, the fertile shoots ascend- ing, smooth, a few inches to as much as 2 feet in height; sheaths smooth, flattened and keeled, vil- lous on each side at the throat; ligule a very short ciliate-fringed membrane; blades flat, 2 to 4 mm. wide, 14 to 2 inches long or on sterile shoots sometimes much longer, more or less scabrous, at least on the margin, sharp-pointed; inflorescence consisting of 3 to 6 slender ascending spikes 1 to 2 inches long, digitate at the summit of the culms, pubescent at the base, the rachis 14 to 14 mm. wide; spike- lets much compressed, often pur- plish, ovate, about 214 mm. long; glumes narrow, pointed, scabrous on the keel, shorter than the spike- let, the lemma pubescent on the margin and often also on the keel. Fig. 46. Capriola Dactylon. Plant show- ing stolons, X 24; spikelet, 7. 216 A TEXT-BOOK OF GRASSES The spikelets face alternately to the right and left, often apparently in a single row. In Europe this grass is called dog’s-tooth, refer- ring to the tooth-shaped old sheaths on the runners, and cock’s-foot, referring to the digitate inflores- cence. In the British West Indies it is called Bahama-grass. 243. Chloris Swartz—A moderate-sized genus, many annual species of which are weeds in the tropics. On ac- count of the silky spikes they are usually handsome grasses. One species, C. Gayana Kunth, has been introduced in the southern states as a meadow- grass under the name of Rhodes-grass. (See ‘Some New Grasses for the South,” Yearbook, U. 8S. Dept. Agr. 1912.) 244. Bouteloua Lag.— Grama-grasses. A genus of about 30 species, all Ameri- can, especially abundant in southwestern United States and on the Mexican plateau. They are important grazing- Fic. 47. Bouteloua gracilis. Inflores- cence, X 1; spikelet, X10. grasses. Bouteloua gracilis (H.B.K.) Lag. (B. oligostachya Torr.). (Fig. 47.) Perennial; culms smooth, tufted, erect, 6 to 18 inches high; sheaths smooth, or the lower somewhat villous, bearing at the throat a tuft of long hairs on each side; ligule very short; blades mostly basal, flat or usually involute, flexuous or curly, 1 to 2 mm. wide, 2 to 4 inches long, scabrous on the margin; spikes usually 2, CHLORIDEZ 217 1 terminal, the other a short distance below, both nearly sessile and more or less ascending, about an inch long, somewhat curved; spikelets sessile, about 5 mm. long, densely crowded on one side of the pubescent rachis; glumes narrow, the upper villous and more or less beset with dark papille, the lemma _ pubescent; rudiment rounded, 3-awned. The end of the rachis does not project beyond the spikelets. The spikes turn with the wind like vanes. In the less arid portions of the Great Plains this species forms a rather compact sod; in drier regions the tufts are isolated. This is some- times called blue grama but to stockmen it is usually known merely as grama. It is the most important economic species of the genus, ranging on the Great Plains from Manitoba to South America and westward into New Mexico, Arizona and southern California. Bouteloua hirsuta Lag. Black grama. Resembles the preceding but differs in the prolongation of the rachis as a naked point 5 to 8 mm. beyond the spikelets, and in the more hairy second glumes with prominent black papilla. The range is about the same as that of the pre- ceding but does not extend so far north. Bouteloua curtipendula (Michx.) Torr. Tall or Side-oat grama. Culms 2 to 3 feet high, the spikes numerous, 30 to 50, arranged, by twisting of the peduncles, along one side of the upper part of the culm for 6 to 10 inches, about 1% inch ' long, the spikelets appressed, 5 to 8 in each spike. Prairies and plains, from Ontario to Montana and south through Mexico to South America. Fic. 48. Bulbilis dactyloides. Staminate plant, X 4; spikelet, x4. 218 A TEXT-BOOK OF GRASSES There are many other species in the southwestern states and in Mexico, but the 3 described above are the best-known economic species. 245. Bulbilis Raf—Buffalo-grass. The single species, B. dactyloides (Nutt.) Raf. (Buchloé dactyloides (Nutt.) Engelm.) (Figs. 48 and 49), a common and often the dominant grass on the Great Plains, is a low stoloniferous perennial that forms a firm sod. The staminate inflores- cence consists of 2 or 3 short 1-sided spikes on a culm a few inches high; the pistillate spikes are hidden among the leaves near the ground. Fie. 49. Bulbilis dactyloides. Pistillate plant, x; cluster of spikelets and floret, <4. CHAPTER XXIII Trips XI. FESTUCEA: A LARGE tribe of about 80 genera, mainly inhabitants of the cooler regions. Spikelets more than 1-flowered, usually several-flowered; inflorescence an open, narrow or sometimes spike-like panicle. If the lemmas are awned, the awn is straight and terminal or rarely from between the teeth of a bifid apex (some species of Bromus and a few species of Festuca). The lemma is divided into several awns at the summit in Pappophorum and Cottea and a few other genera. In some species of Eragrostis the palea is persistent on the inarticulate rachilla. In most of the genera the spikelet breaks up at maturity, each floret falling with a joint of the rachilla, the glumes being persistent on the pedicel. Scleropogon, Monanthochloé, Distichlis and a few species of Poa are dicecious. The blades are broad and petioled in a few tropical genera. Gynerium, Cortaderia, Arundo and Phragmites are tall reeds. Key To THE GENERA OF FESTUCEZ A. Lemmas divided at summit into 3 to several awns or awn-like lobes (only the pistillate in Scleropogon; lemmas more or less 3-toothed in Tridens of the next division). B. Awns 9 or more. c. Divisions of lemma awn-like, plumose; panicle spike-like. Arizona.............PAPPOPHORUM. cc. Divisions membranaceous, awn-pointed; panicle open. Texas to Arizona........COTTEA. BB. Awns less than 9. (219) 220 A TEXT-BOOK OF GRASSES c. Plants dioecious; sexes unlike, the pistillate lemmas long-awned, the staminate awn- less or nearly so; southwestern states (harrostape cal 8 a gee toe eee SCLEROPOGON. cc. Plants perfect; lemmas broad, 5-lobed; spikelets in racemes; annuals. Cali- HGSETIES, «5s ar SRS hea WS ee te ORCUTTIA. 4A. Lemmas awnless or with 1 terminal awn, this sometimes from between 2 teeth (more or less 3-toothed in Tridens). B. Rachilla or lemma with hairs as long as the lemma (only the pistillate in Cortaderia) ; tall reeds with large terminal plume-like panicles. c. Plants dicecious, the staminate spikelets naked; bladesmarrow.< so i.6 <2). ae eee CoRTADERIA cc. Plants perfect; blades broad. (Par. 246). Dp. Lemmas hairy; rachilla naked.........ARUNDO - (Par. 247). pp. Lemmas naked; rachilla hairy......... PHRAGMITES. BB. Rachilla and lemmas naked or pubescent, not with long hairs. c. Plants dicecious. p. Plants low and creeping; spikelets obscure, scarcely differentiated from the short crowded rigid leaves; mud flats along coast. Florida and Cali- TOPRIM soe eid cs SAN Sins er ee ea MONANTHO- DD. Plants erect from creeping rhizomes; [CHLOE. inflorescence a narrow simple exserted pratieles sche 4 ec. li glearins wane ne eee DISTICHLIS cc. Plants not dicecious (except a few species (Par. 249). of Poa). p. Spikelets of 2 forms, sterile and fertile intermixed. E. Fertile spikelets 2- to 3-flowered; ster- ile spikelets with numerous awned glumes; our species perennial (C. cristatus L., crested dog’s-tail, occa- sionally sown in mixtures for THEAMOWE) stretch Wks hae ee Re CYNOSURUS. EE Fertile spikelets 1-flowered, long- awned; sterile spikelets with many obtuse glumes; annual (A. aurewm (L.) Kuntze, Lamarckia aurea Moench, golden top, occasionally cultivated for ornament, commonly introduced on the Pacific coast)... .ACHYRODES. DD. Spikelets all alike. % FESTUCEHA 221 x. Callus and nerves of lemma densely bearded; lemma 3-nerved, the nerves ending in teeth or lobes. r. Empty lemmas 2 below the fertile floret; spikelets with 1 fertile floret and a 3-awned rudiment above; low desert perennials..... BLEPHARI- rr. Empty lemmas none at base of [DACHNE. spikelets. c. Hairs not extending along the 3 conspicuous nerves of the lemma; panicle large and open. REDFIELDIA. cc. Hairs extending from the callus along the nerves of the lemma. H. Palea ciliate-fringed; midnerve excurrent between the lobes Of the lem: ca. 5. 2 ko TRIPLASIS. nH. Palea not ciliate-fringed; the 3 nerves of the lemma often extending into teeth, the apex sometimes 2-lobed..... TRIDENS. EE. Callus and nerves of lemma glabrous or pubescent, sometimes cobwebby but not bearded. r. Plants tufted and creeping, annual; spikelets hidden among the short sharp-pointed leaves. Western... MuNROA. FF. Plants with distinct inflorescence. Gc. Lemmas coriaceous, rounded on the back, smooth and shining, the margin not scarious. Hu. Empty lemmas | to 4 at base of spikelets; spikelets strongly COMIPTeESsed . 1G). owes ee UNIOLA. HH. Empty lemmas 2 to 4 at summit of spikelet; spikelets not compressed ........-.-. DIARRHENA. GG. Lemmas membranaceous, or if somewhat coriaceous, the mar- gins scarious. u. Lemmas 3-nerved (Sphenoph- olis might be sought here). 1.Glumes longer than the lemmas. California....... DISSANTHE- 1. Glumes shorter than the [LIUM. lemmas. J. Spikelets subterete. Spar- ingly introduced from Marepe! oss Gee LRN s Mo.ini4, 222 A TEXT-BOOK OF GRASSES JJ. Spikelets compressed. K. Spikelets 2-flowered; ra- chilla articulate ......... CATABROSA. KK. Spikelets 3- to many- flowered; rachilla usually continuous, the palea persistent after the fall of the lemma........... ERAGROSTIS HH. Lemmas 5- to several-nerved. (Par. 248). 1. Lemmas flabellate, many- nerved; spikelets in close spike-like panicles; annual. AIPORT: «oi pierce Os dye aie 2's ANTHOCHLOA. 11. Lemmas not flabellate. J. Spikelets in 1-sided fascicles, these in a panicle, the branches spreading in anthesis, appressed at THAPUTIOY s/c oe oe es os» ire oe Ae js. Spikelets not in 1-sided (Par. 250). fascicles. K. Palea wing-margined or appendaged on the keels; spikelets long and slender, in racemes. California.. .PLEUROPOGON. KK. Palea not wing-margined nor appendaged. L. Callus bearded (base of lemma cobwebby in species of Poa) spikelets 2- to 4-flowered. M. Rachilla_ pilose, pro- longed above the upper floret; lemma with a short awn just below GEE Cte cee pe Ge GRAPHE- mM. Rachilla naked, not [PHORUM. prolonged ; lemma awn- less but 1 or more of the nerves projecting beyond the apex...... ScoLOcHLOA. LL. Callus not bearded. M. Spikelets as broad as long, somewhat heart- shaped; lemmas broad, closely imbricated, horizontally spreading. BRIzA. MM. Spikelets longer than broad. FESTUCEZ 223 Nn. Lemmas papery, 8ca- rious-margined, nar- row and awned or acuminate, or broad and obtuse (the up- per lemmas then re- duced to a club- shaped rudiment enfolded by the up- per broad lemmas); spikelets tawny or purplish, not green.. MELIca. NN. Lemmas not scarious- margined, or if slightly so, only at the tip, the lemma green (Poa). o. Lemma _ obscurely nerved, rounded on back, obtuse, awn- less; glumes small, much shorter than lemmas. Low plants of the seashore and of alkaline soil ....PUCcCINELLIA. oo. Lemma distinctly nerved; glumes nearly as long as the first lemma. p. Nerves of lemma prominent, paral- lel; lemma broad, obtuse, awnless, 8- to 9-nerved......PANICULARIA. pp. Nerves of lemma evident but not prominent. q. Lemmas obtuse or acutish, awn- less, somewhat searious at tip, 5-nerved, some- times cobwebby af, DARE ..s%.% «>» Pos (Par. 251): aq. Lemmas acute or awned. R. Lemmas entire, often awned, (Par. 254). rounded below. FESTUCA 224 246. Cortaderia Stapf—Pampas-grass. A TEXT-BOOK OF GRASSES RR. Lemmas bifid at apex, often ~ awned from between the teeth; spikelets large, some- times com- pressed and (Par. 258). keeled........BRomuUS The orna- mental species, C. argentea (Nees) Stapf (Fig. 50), is a large reed growing in clumps, the blades numerous, long and narrow, drooping, the flower-stalk tall and slender, bearing a large silvery white or rosy plume 1 to 2 feet long. A native of Argentina, cultivated for ornament and, in California, on a commercial scale for the plumes. Another species, C. jubata (Lem.) Stapf, with smaller and more lax lavender-colored plume, is occasionally cultivated. A related plant, the uva-grass Gynerium sagittatum (Aubl.) Beauv. (G. sac- Fia. 50. tea. greatly pistillate spikelet (a), of pistillate spikelet (b), glumes Cortaderia argen- A group of inflorescences reduced; glumes of florets (c), and florets (d) of staminate spikelet, X1. (U.S. Dept. Agr., Div. Agrost., Bull. 20.) charoides Humb. & Bonpl.), sometimes cultivated, is a tall coarse leafy reed, 12 to 30 feet high, with creeping root- stocks, the lower leaves soon dropping, leaving the stem naked below. Tropi- cal America; not hardy. 247. Arundo L.—Giant-reed. The species found in the United States, A. Donax L., is a tall stout reed, 5 to 10 feet high, with somewhat woody finally much- branched stem, broad clasping blades and large plumes or pani- cles. A native of the Mediter- ranean region, cultivated in the southern states for ornament. It has escaped along irrigation FESTUCEZ 225 ditches from Texas to Cali- fornia. 248. Eragrostis Host— A large genus of over 100 species, found throughout the warmer regions of the world. Annuals or peren- nials with open, narrow or spike-like panicles; spike- lets many-flowered, awn- less; rachilla usually con- tinuous, the paleas often persistent after the fall of the lemmas and fruits. Sev- eral species are weeds intro- duced from the Old World. One of these, EF. cilianensis (All.) Link (EF. megastachya (Koel.) Link) (Fig. 51), called snake-grass or stink- TS grass, emits a disagreeable | odor from glands along the of {Sait Eragrostis cflianensis. Plant keels of the lemmas. Teff, {hich come of the florets have fallen, a. E. abyssinica (Jacq.) Link, (U.S. Dept. Agr., Div. Agrost., Bull. 17.) is an important food-plant in Abyssinia and has been tried in other countries as a forage plant. Several species are occasionally cultivated for ornament, the panicles being used for dry bouquets. 249. Distichlis Raf—Salt-grass. Low dicecious per- ennials of seacoasts and alkaline flats. Only 1 species, D. spicata (L.) Greene (Fig. 52), is found in the United States. This is common in salt-marshes throughout the country. The culms are erect fom extensively creeping fe) 226 A TEXT-BOOK OF GRASSES rhizomes, with short distichous blades and narrow few- flowered panicles of many-flowered spikelets. In regions where it is abundant, salt-grass is utilized for forage, but f on account of the excess of mineral constituents it is of inferior quality. 250. Dactylis L.—The single species, D. glome- rata, a native of Europe, is commonly cultivated as a forage grass under the name of orchard- grass. It is a tussock- forming perennial, 2 to 4 feet high, with flat blades and narrow panicles. The spikelets are in 1-sided fascicles or small heads at the ends of the few principal branches of the panicle. These branches spread at the time of flowering but close at maturity. The lemmas are fringed or ciliate on Fig. 52. Distichlis spicata. Staminate the sharp keel. plant (at left) and pistillate plant (at ; : right) reduced; pistillate and staminate Dactylis glomerata L. (Fig. cc eas 53.) Orchard-grass. Perennial, in large tufts without creeping rootstocks; culms erect, smooth, 2 to 4 feet high; sheaths compressed and keeled, more or less retrorsely scabrous, closed for a portion of their length, sometimes nearly to the throat; ligule prominent, thin and papery, pointed, usually lace- rate, the uppermost as much as 14 inch long; blades flat, usually scabrous on both surfaces, elongated, as much as \ inch wide, FESTUCEA 227 tapering into a slender point; panicle 3 to 6 inches long, the branches few and stiff, singly dis- posed, naked below, bearing a few l-sided clusters of spikelets, the clusters being about 14 inch wide, green or purplish; spikelets com- pressed, about 14 inch long usu- ally 3- or 4-flowered; first glume l-nerved, acute; second glume longer than the first, 3-nerved, acuminate, ciliate on the keel; lem- mas rather indistinctly 5-nerved, ciliate on the keel, short-awned. During the flowering period the branches are spread open by the turgidity of prominent cushions of tissue in the basal angle. Later these cushions shrink and _ the branches become appressed so that in fruit the panicle is narrow and almost spike-like. The tufts of orchard-grass soon develop at the base into large tussocks. In Eng- land this grass is known as cock’s- foot. 251. Poa L.—Blue-grass. A large genus of over 100 species, found throughout the world in the cooler parts and in the high mountains of the tropics. Annuals or mostly perennials often with creeping , rhizomes. Spikelets in narrow Ne Fic. 53. Dactylis glomerata. In- florescence, X 24, spikelet, <7. or open panicles, 2- to 6-flowered; lemmas 5-nerved, awn- less, somewhat scarious at tip, smooth or hairy on the nerves, sometimes cobwebby at base. This is one of the 228 A TEXT-BOOK OF GRASSES most important genera of forage grasses. The species are ab: ndant in the grazing areas of our western mountains an several species are cultivated. ‘252. Kentucky blue-grass——Culms from a few inches to 2 feet or more in height from slender creeping rhizomes; sheaths smooth; ligule short; blades flat or somewhat folded, ending like most species of the genus, in a boat- shaped blunt point, panicle 2 to 4 inches long or sometimes larger, pyramidal, open, the lower branches in groups of about 5; spikelets 3- to 5-flowered, 4 to 5 mm. long; lemmas pubescent on the keel and marginal nerves, bearing a tuft of cobwebby hairs at base. Commonly cultivated as a lawn- and pasture-grass. Poa pratensis L. (Fig. 54.) Kentucky blue-grass. Perennial, in tufts but producing slender creeping rootstocks; culms slender, erect, smooth, terete or slightly flattened, 1 to 3 feet high; sheaths smooth, sometimes slightly keeled; ligule membranaceous, short, truncate, about 1 mm. long; blades, especially the basal, long and narrow, flat or usually partly folded or conduplicate, usually not over 4 mm. wide, the uppermost 1 to 3 inches long, appressed, slightly roughened on the margins and keel, especially toward the boat-shaped tip; panicle open, pyramidal or oblong, 3 to 6 inches long, the scabrous branches naked below, the lower in whorls of usually 5, one being stronger; spikelets ovate or lanceolate, flat- tened, 4 to 6 mm. long, usually 3- to 5-flowered, the ultimate pedi- cels about 1 mm. long; glumes narrow, acute, the first 1-nerved, the second 3-nerved; lemma 5-nerved, acute, hyaline or papery and often purple-tinged at apex, about 4 mm. long, the keel and margi- nal nerves pubescent, the base bearing a tuft of cobwebby hairs. The boat-shaped apex of the blades is characteristic of the genus. Blue-grass is a native of Europe and may also be native in the northern parts of North America. In open dry or sterile soil the flowering culm may be only a few inches in height. In color the foliage is a dark green and does not have a blue color as the name would indicate. As it flowers in June, the name June-grass is applied to this species in parts of the northern United States. PESTUCEA 229 253. Other economic species of Poa.—Compared with Kentucky blue-grass, the other species of Poa are of slight importance, although Can- ada blue-grass attains some im- portance locally (Par. 35). Of the other species 2 are advertised by seedsmen and are occasionally used in mixtures. Canada blue-grass (Poa com- pressa L.)—Culms wiry, flattened, with numerous creeping rhizomes, not tufted; panicles narrow, the branches in pairs. This resembles P. pratensis but is bluish green rather than dark green. Cultivated as a pasture-grass. Called also wire-grass and flat-stem. Rough - stalked meadow - grass (Poa trivialis L.)—This resembles P. pratensis but differs in the absence of rhizomes and in having scabrous sheaths and a long ligule. Sometimes cultivated as a meadow- grass. Fowl meadow-grass (Poa triflora Gilib.; P. serotina Ehrh.)—Culms 1 to 4 feet high, tufted but with- out rhizomes; sheaths smooth; — = == Fic. 54. Poa pratensis. Plant, X14; spikelet and floret, X65. = Ms: Y 4, gy x ee of, AY a SZ = grasses, 138. Tridens, 221. Weeds, 75-78. flavus, 39. annual, 76. Trifolium, 41. brome-grasses, 77. incarnatum, 41-42, 52. biennial, 76. hybridum, 41. grasses as, 76. pratense, 41. perennial, 76. repens, 41-42. eradication of, 78. Triplasis, 221. Wheat, 238. Tripogon, 213. classification of, 242. Tripsacum, 159. durum, 242. dactyloides, 160. grass, 238. Trisetum, 209. slender, 45. Tristeginee, 175. origin of, 240. Triticum, 235, 236, 238. Polish, 241, 242. egilopoides, 240. Wild grasses, production of, 19. estivum, 241, 242, Winter fat, 21. compactum, 240. Wire-grass, 32, 39. dicoccoides, 240. dicoccum, 239, 240, 241, 242. Xerophytes, 140-145. durum, 240, 242. monococcum, 240, 241, 242. Zea, 159. ovatum, 240. mays, 161. polonicum, 240, 241, 242. Zizania, 190, 191. sativum, 238, 241, 242, 243. aquatica, 191. compactum, 243. latifolia, 191. dicocecum, 243. palustris, 7, 146, 191. durum, 243. injury to seeds of, by drying, spelta, 243. 138. tenax, 243. Zizaniopsis, 190. turgidum, 243. miliacea, 146. vulgare, 243. Zoysia pungens, 175. spelta, 239, 240, 242, Zoysiez, 173, 388 following pages contain advertisements of a few of The Macmillan books on kindred subjects. NEW VOLUMES IN The Rural Text-Book Series Epitep spy L. H. BaiLey TEXT-BOOK ON FORAGE CROPS By Proressor C. V. PIPER Of the United States Department of Agriculture Cloth, rz2mo A clear and-concise account of the present knowledge of forage cropping in North America, intended primarily as a text-book for the use of agricultural college students. The author presents the subject in such a way as to make the student realize the shortcomings of the present knowledge on the subject, as well as the progress which has been definitely accomplished. All the plants and crops which are used for forage and for hay are described, and their botan- ical characteristics and means of cultivation are carefully discussed. The grasses, alfalfa, the clovers, the millets, and the various fodder crops are all treated. SMALL GRAINS By M. A. CARLETON Cerealist of the United States Department of Agriculture Cloth, 12mo. Preparing The cereal grains and buckwheat are described carefully. Their methods of cultivation and of handling and marketing are thoroughly discussed. Among the grains thus treated are wheat, oats, rye, barley, and the minor crops. This book will prove an admirable complement to Montgomery’s “‘ The Corn Crops.” Both these books are intended primarily for use as texts in college courses, and may very well be used in conjunction in the general course on grain crops. These books also are of distinct interest and value to the farmer. THE MACMILLAN COMPANY Publishers 64-66 Fifth Avenue New York NEW VOLUMES IN THE RURAL TEXT-BOOK SERIES IRRIGATION By JOHN A. WIDTSOE President of the Utah Agricultural College Illustrated, Cloth, r2mo Although much of the writing on irrigation has been from the engineering point of view, this book is written distinctly from the point of view of practical farming. President Widtsoe has drawn not only upon his own intimate knowledge of conditions in an irrigated country, but also upon all the available literature on the application of water to land for irrigating purposes. The effect of water on the soil, the losses by seepage and evaporation, the service that water renders to the plants, and the practical means of employing water for the growing of the different crops are all discussed clearly and thoroughly. WEEDS By ADA E. GEORGIA Of the New York State College of Agriculture at Cornell University Illustrated, ‘Cloth, 12mo A summary of our present knowledge regarding weeds as they affect horti- cultural and agricultural practices. The relations of weeds to agriculture are described, and the causes making certain plants weeds are explained. Every separate species of weed known to occur in the United States or Canada is de- scribed, and its range and habitat stated. The crops which each species partic- ularly infests and the means of controlling each species are also discussed. Between 300 and 4oo original illustrations, made directly from the plants, greatly enhance the practical value of this book. FIELD CROPS By GEORGE LIVINGSTON Assistant Professor of Agronomy, Ohio State University Illustrated, Cloth, 12mo, $1.40 net This text is intended to meet the needs of agricultural high schools and of brief courses in Field Crops in the colleges. Based on actual experiment, it points out the “ better way” of raising field crops; of selecting the field; of pre- paring the soil; of sowing the seed; of cultivating the plant; of harvesting the crop. It is to be fully illustrated with reproductions from photographs of un- usual excellence. THE MACMILLAN COMPANY Publishers 64-66 Fifth Avenue New York 1HE CORN CROPS By E. G. MONTGOMERY (Rural Textbook Series) Cloth, 347 pages, index, ill., 12mo, $1.60 net A valuable handbook on maize, kafirs and sorghum crops, including the grain sorghums, the sweet sorghums for syrup or forage, and the broom corns. Adapted to both elementary and advanced classes of readers, as the theoretical principles of physiology, of production as related to climate and soils, and of the adaptation of the plant to the environment are separated from the practical treatment of cultural methods. These methods of culti- vation may, therefore, be understood by the beginning student in school or college and by the busy farmer, without a previous study of the theoretical portions of the book. FORAGE CROPS By EDWARD V. VOORHEES (Rural Science Series) Cloth, 12mo, $1.50 net Deals with the whole subject of forage in a practical and up-to-date manner. It suggests useful and practical rotations and soiling systems, and gives methods of seed- ing, culture and use. An eminently practical book. 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