20 6 GRAMINEAE. 



14. Poa debilis Torr. Weak Spear-grass. (Fig. 472.) 



Poa debilis Torr. Fl. N. Y. 2: 459. 1843. 



Culms i-2^ tall, erect, slender, simple, somewhat 

 flattened, smooth and glabrous. Sheaths compressed, 

 much shorter than the internodes; ligule X // -i // long; 

 leaves i / -4^ / long, i //r 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, iX / ~3 / l n g; spikelets 2-4- 

 flowered, i>^ // -2 // long, their pedicels longer; empty 

 scales unequal, acute, the first i-nerved, shorter than 

 the 3-nerved second one; flowering scales \Yt" 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. 



Poa autumnalis Muhl. Flexuous Spear-grass. (Fig. 473.) 



Poa autumnalis Muhl. ; Ell. Bot. S. C. & Ga. i: 159. 1817. 

 Poa flexuosa Muhl. Gram. 148. 1817. Not J. E. Smith. 

 1803. 



Culms i-3 tall, erect, slender, simple, smooth and 

 glabrous. Sheaths usually much shorter than the in- 

 ternodes; ligule YL" long; leaves \" wide or less, 

 smooth beneath, rough above, those of the culm \Y*'~ 

 6' long, the basal much longer; panicle s'-g' in 

 length, the branches long and slender, spikelet-bearing 

 at the extremities, 2'-$' long; spikelets 3-5-flowered, 

 2 X // ~3 // l n g> 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 sylvestris A. Gray. Sylvan Spear-grass. (Fig. 474.) 



Poa sylvestris A. Gray, Man. 596. 1848. 



Culms i-3 tall, erect, slender, simple, slightly 

 flattened, smooth, glabrous. Sheaths shorter than 

 the internodes; ligule Y* ff long or less; leaves smooth 

 beneath, rough above, \ ff -$' f wide, those of the 

 culm \Yt'-&' in length, the basal much longer; pan- 

 icle 3 / ~7 / in length, the branches spreading or ascend- 

 ing, i >"2-3' long, spikelet-bearing at the extremities; 

 spikelets 2-4- flowered, i // -2 // long; empty basal scales 

 acute, the lower i-nerved, the upper longer and 3- 

 ncrved; flowering scales about iX x/ l n g> 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. 





