140 FLORA. 



2-4-flowered, 2-4 mm. long; flowering scales about 2.5 mm. long, webbed at the 

 base, obtuse, often pubescent bslow, 5 -nerved, the midnerve pubescent nearly its 

 entire length and the marginal nerves below the middle. In thickets and meadows, 

 N. Y. to Wis. and Neb., south to N. Car., La. and Kans. June-July. 



12. Poa autumnalis Muhl. FLEXUOUS SPEAR-GRASS. (I. F. f. 473.) Culms 

 3-9 dm. tall. Leaves 2 mm. wide or less, smooth beneath, rough above, those of 

 the culm 3. 75-15 cm. long, the basal much longer; panicle 7.5-22 cm. in length, 

 the branches long and slender, spikelet-bearing at the extremities, 5-12.5 cm. long; 

 spikelets 3-5 -flowered, 5-6 mm. long ; empty basal scales acute, the first I -nerved, 

 narrow, shorter than the broad 3-nerved second; flowering scales rounded orretuse 

 at the apex, 3-4 mm. long, not webbed at the base, pubescent on the lower part, 

 5 -nerved, the midnerve silky-pubescent for three -fourths its length. In woods, 

 N. J. and Penn. to Ky., south to Fla. and Tex. March-May. 



13. Poa alsodes A. Gray. GROVE MEADOW-GRASS. (I. F. f. 475.) Culms 

 2-7.5 dm. tall. Leaves usually rough, 2-4 mm. wide, those of the culm 5-20 cm. 

 in length, the basal longer ; panicle 8-20 cm. in length, the branches spreading or 

 ascending, 3.5-7.5 cm. long, spikelet-bearing at the ends ; spikelets 2-3-flowered, 

 about 5 mm. long; flowering scales acute, about 4 mm. long, webbed at the base, the 

 midnerve pubescent near the base, the marginal nerves naked, the intermediate 

 ones very faint. In woods and thickets, N. S. to Ont. and Minn., south to N. Car. 

 and Tenn. May-June. 



i^. Poa Wolfii Scribn. WOLF'S SPEAR-GRASS. (I. F. f. 476.) Culms 

 3-9 dm. tall. Leaves 2 mm. wide or less, smooth beneath, rough above, those of 

 the culm 5-10 cm. in length, the basal much longer; panicle 7.5-15 cm. in length, 

 lax, its branches erector ascending, flexuous, 3.75-6 cm. long; spikelets 2-4- 

 flowered, 5-6 mm. long; scales acute; flowering scales about 4mm. long, copiously 

 webbed at the base, 5 -nerved, the marginal and midnerves silky-pubescent for more 

 than half their length, the intermediate nerves prominent, naked. 111., Tenn., Minn., 

 Kans. 



15. Poa brevifolia Muhl. SHORT-LEAVED SPEAR-GRASS. (I. F. f. 477.) 

 Culms 3-9 dm. tall, erect. Leaves smooth beneath, rough above, 24 mm. wide, 

 abruptly acute, those of the culm 1.25-10 cm. long, the uppermost sometimes al- 

 most wanting; basal leaves usually equalling or nearly as long as the culm; panicle 

 6-12.5 cm. in length, open, the branches ascending, widely spreading or often re- 

 flexed, 3.75-7.5 cm. long, spikelet-bearing at the ends; spikelets 3-6-flowered, 5-7 

 mm. long; flowering scales slightly webbed at the base, 4-5 mm. long, obtuse, 

 5 -nerved, the keel and marginal nerves sparingly pubescent, the intermediate nerves 

 prominent, naked. In rocky woods, N. J. and Penn. to 111., south to N. Car. and 

 Tenn. April-June. 



16. Poa cenisia All. ARCTIC SPEAR-GRASS. (I. F. f. 465.) Smooth and 

 glabrous. Culms 1-4 dm. tall, erect, slender; leaves 2.5-10 cm. long, 1-2 mm. 

 wide; panicle 2.5-10 cm. in length, open, the branches generally widely spreading 

 and more or less flexuous, 2.5-6 cm. long ; spikelets 3-5 -flowered, 5-7 mm. long ; 

 lower scales acute or acuminate, i-3-nerved ; flowering scales about 4 mm. long, 

 faintly 5 -nerved, the nerves short-pilose on the lower half, minutely pubescent be- 

 tween the nerves, somewhat webbed at the base. Greenland and Lab. to Alaska. 

 Also in Europe. Summer. 



17. Poa pseudopratensis Scribn. and Rydb. PRAIRIE MEADOW-GRASS. (I. 

 F. f. 467.) Culms 3 -6.5 dm. tall. Ligule 4 mm. long, acute, decurrent; leaves 2-6 

 mm. wide, smooth beneath, a little rough alx>ve and on the margins, those of the 

 culm 2.5-8 cm. long, the basal 1.5-2.5 dm. in length ; panicle 5-12.5 cm. long, 

 open, the branches spreading or ascending, 2.5-5 cm. long; spikelets 3-5 -flowered, 

 6-8 mm. long, exceeding their pedicels; lower scales nearly equal, acute, 3-nerved; 

 flowering scales acutish, about 3 mm. long, rough above, 5 -nerved, pubescent be- 

 tween the nerves below, the marginal nerves and midnerve silky-pubescent about 

 half their length. Manitoba and Assiniboia to Neb. and Colo. 



18. Poa alpina L. ALPINE SPEAR-GRASS. (I. F. f. 464.) Smooth and 

 glabrous. Culms 1-4.5 dm. tall ; ligule 2 mm. long, truncate; leaves 2.5-7.5 

 cm. long, 2-4 mm. wide, abruptly acute; panicle 2.57.5 cm. in length, the 

 branches generally widely spreading, 2.5 cm. long or less; spikelets 3-5 -flowered, 

 $-6 mm. long; lower scales broad, glabrous, rough on the keel, acute; flowering 



