206 GRAMINEAE. 
14. Poa débilis Torr. Weak Spear-grass. (Fig. 472.) 
Poa debilis Torr. Fl. N. Y. 2: 459. 1843. 
Culms 1°-214° tall, erect, slender, simple, somewhat 
flattened, smooth and glabrous. Sheaths compressed, 
much shorter than the internodes; ligule 14’/-1’’ long; 
leaves 1/-414’ long, 1’ wide or less,.erect, smooth be- 
neath, rough above; panicle 2/-6’ in length, open, 
often nodding at the top, the branches erect or ascend- 
ing, sometimes spreading, 114’-3’ long; spikelets 2-4- 
flowered, 14’’-2/’ long, their pedicels longer; empty 
scales unequal, acute, the first 1-nerved, shorter than 
the 3-nerved second one; flowering scales 114’ long, 
obtuse, sparingly webbed at the base, 5-nerved, the 
nerves naked. 
In woods, Nova Scotia and New Brunswick to Ontario 
and Minnesota, south to Rhode Island, Pennsylvania and 
Wisconsin. June-Aug. 
15. Poa autumnalis Muhl. Flexuous Spear-grass. (Fig. 473.) 
Poa autumnalis Muhl.; Ell. Bot. S. C. & Ga. 1: 159. 1817. 
iar Na Muhl. Gram. 148. 1817. Not J. E. Smith. 
Culms 1°-3° tall, erect, slender, simple, smooth and 
glabrous. Sheaths usually much shorter than the in- 
ternodes; ligule 14’’ long; leaves 1’’ wide or less, 
smooth beneath, rough above, those of the culm 114/— 
6’ long, the basal much longer; panicle 3/-9’ in 
length, the branches long and slender, spikelet-bearing 
at the extremities, 2’-5’ long; spikelets 3—-5-flowered, 
2'4/’-3’’ long; empty basal scales acute, the first 
I-nerved, narrow, shorter than the broad 3-nerved 
second; flowering scales rounded or retuse at the 
apex, I!2/’-2/’ long, not webbed at the base, pubes- 
cent on the lower part, 5-nerved, the midnerve silky- 
pubescent for three-fourths its length. 
In woods, New Jersey and Pennsylvania to Kentucky, 
south to Florida and Texas. March—May. 
16. Poa sylvéstris A. Gray. Sylvan Spear-grass. (Fig. 474.) 
‘ Poa sylvestris A. Gray, Man. 596. 1848. 
Culms 1°-3° tall, erect, slender, simple, slightly 
flattened, smooth, glabrous. Sheaths shorter than 
the internodes; ligule 1%4’’ long or less; leaves smooth 
beneath, rough above, 1//-3/’ wide, those of the 
culm 114’-6/ in length, the basal much longer; pan- 
icle 3’-7’ in length, the branches spreading or ascend- 
ing, 114-3’ long, spikelet-bearing at the extremities; 
spikelets 2-4-flowered, 1/’—2’’ long; empty basal scales 
acute, the lower 1-nerved, the upper longer and 3- 
nerved; flowering scales about 14’ long, webbed at 
the base, obtuse, often pubescent below, 5-nerved, the 
midnerve pubescent nearly its entire length and the 
marginal nerves below the middle. 
In thickets and meadows, New York to Wisconsin, 
south to North Carolina, Louisiana and Kansas. 
Branches of the panicle sometimes reflexed when old. 
June-July. 
