Graminaceae . 43 
obtuse or abruptly acute. Lemma wide, membranous, becoming hard, obtuse-truncate, 
terminating in an awn; awn deciduous, simple, more or less bent near the base. Palet 
2-keeled. Stamens 3. Grain oblong-ellipsoid, free. (Gk. oryza=rice, opsis—form. ) 
A. Lemma densely covered with conspicuous long white hairs; panicles loose; not alpine 
species. 
B. Leaf-blade smooth; lemma narrowly elliptic; awn 8—12 mm. long. E. (Stipa 
bloomeri. ) 0. bloomeri Rick. 
BB.  Leaf-blade scabrous; lemma broadly oval; awn 3—5 mm. long. E. (Erio- 
coma cuspidata; O. hymenoides.) 
0. cuspidata Benth. (Indian Millet) 
AA.  Lemma-hairs not dense nor conspicuous if present; panicle narrow (except in (O. 
kingii) ; alpine species (except O. hingit). 
C. Awn of lemma 3—4 mm. long. C. E. 
O. exigua Thurb. (Small Mountain-rice) 
CC. Awn of lemma 10—15 mm. long. 
D. Alpine; rays of panicle bearing 2—4 spikelets each; lemma smooth. E. 
0. hendersoni Vas. 
DD. Not alpine; rays of panicle bearing 1—2 spikelets each; lemma with short 
hairs on lower half. E. (Stipa hingii.) 
0. kingii Beal 
MUHLENBERGIA 
Perennial, rarely annual. Stems often wiry. Leaf-blade often very thin. Spikelets 
small, variously panicled. Rachilla articulate above the glumes, not extending beyond 
the palet. Glumes persistent, membranous or hyaline, keeled, acute or mucronate or 
short-awned; the first 1-veined, sometimes minute or obsolete; the second |—3-veined. 
Lemma 3—5-veined, firm or slender, acute or obtuse, 2-toothed, mucronate or awned. 
Palet hyaline, 2-keeled. Stamens usually 3. Stigmas plumose. Grain narrow, sub- 
terete, free. (Honor of Henry Muhlenberg,-an American botanist. ) 
A. Lemma acuminate but awnless; glumes |1/,—2 times as long as the lemma. W. 
C. E. (M. glomerata.) M. racemosa B. S. P. (Wild Timothy) 
AA. Lemma long-awned; glumes nearly as long as the lemma or shorter. 
B. Basal hairs not more than 1/7 as long as the lemma; lemma 2.7 mm. long. E. 
M. sylvatica setiglumis Wats. (Woodland Drop-seed) 
BB. Basal hairs as long as the lemma; lemma 3 mm. long.. E. 
M. comata Benth. (Woolly Drop-seed) 
COLEANTHUS MOSS-GRASS 
Plant 2.5—7.5 cm. high. Spikelets in umbellate clusters and these in simple 
or branched panicles, very small. Glumes none. Lemma hyaline, persistent, ovate, 
keeled, with a short terminal awn. Palet shorter and wider than the lemma, persist- 
ent, 2-keeled, divided or 2—4-toothed. Stamens 2. Stigma denticulate with subulate 
hairs. Grain narrowly oblong, slightly compressed, deciduous. On mud flats. (Gk. 
koleos=sheath, anthos—flower; flowers much enclosed in upper leaf.) W. 
C. subtilis Seid. 
POLYPOGON BEARD-GRASS 
Annual or perennial. Leaf-blades flat. Spikelets in dense spike-like or slightly 
interrupted and spreading panicles; pedicels jointed, with a tuft of short hairs above 
