GRAMINACEAE (GRASS FAMILY) 39 



bristle. Glumes 2 (none in Coleanthus), subequal or unequal, usually as 

 long as the lemma or longer. Palet veinless or 2-veined, but i-veined in 

 Cinna and wanting in some species of Agrostis. Grain unfurrowed. 



A. Plants 2-8 cm. high; glumes none; spikelets hardly i mm. long. W. (Gk. 

 koleos = a sheath, anthos = a flower; inflorescence much inclosed in upper leaf.) 



Coleanthus subtilis (MOSS GRASS) 



AA. Plants taller; glumes present; spikelets longer. 

 B. Inflorescence a dense spikelike (Timothy-like) cluster. 



C. Lower glume 4-6 times as long as the lemma not considering awn, and at least 

 a half longer than the upper glume; glumes awnless; lemma-awn termina.'., 3-5 

 mm. long. U. (Gk. gastros = stomach, eidos = like; glume is swollen at base.) 



Gastridium lendigerum (NIT GRASS) 

 CC. Not as above in all characters. 

 D. Lemma with a terminal awn 0.510 mm. long. 



E. Lemma with a tuft of hair at base as long as the lemma. (Honor of H. 

 Muhlenberg, an American botanist.) Muhlenbergia (DROPSEED) 



EE. Lemma without a tuft of hair at base. (Gk. polys = many, pogon = 

 beard.) Polypogon (BEARD GRASS) 



DD. Lemma awnless or with a dorsal awn. 



F. Lemma with a tuft of hair at base. (Gk. kalamos = a reed, agrostis = a 

 grass.) Calamagrostis (REED GRASS) 



FF. Lemma without a tuft of hair at base, though often ciliate on the keel. 

 G. Glumes not conspicuously compressed-keeled; inflorescence distinctly lobed 

 and raceme-like. (Gk. agros = a field; from the habitat.) 



Agrostis (BENT GRASS) 

 GG. Glumes conspicuously compressed-keeled; inflorescence a dense terete 



spike not or hardly lobed. 



H. Lemma with a dorsal awn 2-16 mm. long ; glumes united for J- their 

 length at base. (Gk. alopex = a fox, oura = a tail; referring to the spike.) 



Alopecurus (FOXTAIL GRASS) 



HH. Lemma awnless; glumes not united. PHLEUM (p. 41) 



BB. Inflorescence either plainly a panicle or if spikelike the spikelets distant, and 



thus the spike not dense. 



I. Lemma with a terminal awn 0.3-20 cm. long; glumes sometimes awned. 

 J. Lemma of fertile flower thin, membranous. (See E.) 

 JJ. Lemma of fertile flower firm, hardened. 



K. Lemma awn 3-branched. (L. arista = an awn.) Aristida (3-AWNED GRASS) 

 KK. Lemma awn not branched. 



L. Lemma awn twisted, persistent. STIPA (p. 40) 



LL. Lemma awn not twisted, deciduous. ORYZOPSIS (p. 40) 



n. Lemma awnless or with a dorsal awn 1.2 cm. or less long; glumes awnless. 

 M. Lemma with a tuft of hair at base. 



N. Glumes with awns 2-5 mm. long, about equal; lemma 3-veined. (See E.) 

 NN. Glumes awnless. 



O. Lemma i-veined; lower glume J-f as long as the upper. E. (Gk. kalamos 

 = a reed; Vilfa = another genus of grasses; hence a reedlike Vilfa.) 



Calamovilfa longifolia (SAND GRASS) 



OO. Lemmas-veined; lower glume f to equaling the upper. (See F.) 

 MM. Lemma without hairs at base. 

 P. Palet half as long as its lemma or shorter, often none; glumes exceeding the 



lemma; stamens 3. (See G.) 



PP. Palet over half as long as its lemma ; glumes not exceeding the lemma 

 (except in Cinna latifolia). 



