POACEAE . 137 
Glumes not cil 
Glumes of fa tile Spikelet dilated above the D plant annual. 1. H. pusillum. 
Glumes not RS ted, all awn-like: plant perennial. 2. H. nodosum. 
Glumes, or some of them, ciliate: plant annual, 3. H. murinum. 
1. H. pusillum Nutt. Stem 10-40 em. tall: spike narrow, erect, 2-7 em. long: 
first glume of each lateral Jd and both glumes of central spikelet dilated 
above the base.—Open S, vari 
uo Fla. to Calif., Wash.. Ohio, to 
Me., and D. C.— — (Mea .) 
2. H. nodosum L. Plant larger than H. 
pusillum, the st stems tufted, commonly 30-60 
ik 0 mm. wi ri 
Plain, in ali and in Piedmont northward. 
m L. Stem bushy-branched, 
3. H. 
spreadi ing e 5-7 cm. long, often partly 
inelosed in the me inflated sheath: 
glumes entral spikelet narrowly 
spindle-form, 3-nerved, i cage on both 
margins, the nerves scabrous: awns 2-3 em. gr —Fields, waste- T and 
open ground, various provinces, Ala. to Mass.; also W U. S. Nat. of Eu. 
: YMUS L. Erect usually rather tall perennials, with flat blades 
and terminal spikes. Spikelets 2- to 6-flowered, sessile in pairs (rarely in 3’s), 
on a continuous rachis, the rachilla Re above the glumes and be- 
tween the florets; glumes P usually rigid, sometimes indurate below, 
narrow, sometimes subulate, 1- sever ee acute to d somewhat 
asymmetric and placed in front p the spikelet: lemmas rounded on the bae 
or nearly terete, obscurely 5-nerved, acute or usually awned fon the. tip.— 
Twenty-five species, in the temperate regions of the Northern Hemisphere.— 
WILD-RYES. LYME-GRASSES. BUFFALO-RYES. 
Glumes narrowly lanceolate, more or less indurate at base. 1. E. virginicus. 
Glumes very narrow with about 2 strong nerves. 
Leaf-blades pubescent. 2. E. striatus. 
Leaf-blades glabrous. 3. E. riparius. 
E. virginicus L. Stem 60—100 cm. tall: spike erect, often included at base 
in the upper leaf- EE nd elets glabrous, fius gluines s rigid, broadened and 
bowed out abov e the e yellowi E ndur 
lemmas awned, the awn mostly 1 FP m. long. 
—(TERRELL-GRASS.)—Moist woods, various 
provinces, Fla. to Tex., Mont., and Newf.— 
o 
: E. 
hel bila lal ad, with villous hirsute 
lemmas and gum s, within the range of the 
spec E. sere australis with narrow 
Sume which, like the lemmas, are villous- 
hirsute and with long awns, Ga. to Tex. and 
Mass.; E. virginicus glabriflorus, with glab- 
rous spikelets, Fla. to Tex., Nebr., and Md. 
2. E. striatus Willd. Stem bann 50-100 
em. tall: leaf-blades 6-10 m wide, villous 
