15. Poa Alsodes A. Gray. Grove Meadow-Grass

Fig. 618

Poa alsodes A. Gray, Man. Ed. 2, 562. 1856.

Culms 8'-2 1/2° tall, erect, slender, simple, smooth and glabrous. Sheaths usually longer than the internodes; ligule 1/2" long; blades usually rough, 1"-2" wide, those of the culm 2'-8' in length, the basal longer; panicle 3 1/2'-8' in length, the branches spreading or ascending, 1 1/2'-3' long, spikelet-bearing at the ends; spikelets 2-3-flowered, about 2 1/2" long; scales very acute, the empty basal ones unequal, the lower 1-nerved, the upper 3-nerved; flowering scales about 2" long, webbed at the base, the midnerve pubescent near the base, the marginal nerves naked, the intermediate ones very faint.

In woods and thickets, Quebec to Minnesota, south to North Carolina and Tennessee. May-June.

16. Poa Wolfii Scribn. Wolf's Spear-Grass

Fig. 619

Poa Wolfii Scribn. Bull. Torr. Club 21: 228. 1894.

Culms 2º-3° tall, erect, slender, simple, smooth and glabrous. Sheaths shorter than the internodes; ligule 1/2" long; blades 1" wide or less, smooth beneath, rough above, those of the culm 2-4' in length, the basal much longer; panicle 3'-6' in length, lax, its branches erect or ascending, flexuous, 1 1/2'-2 1/2' long; spikelets 2'-4'-flowered, 2i"-3" long; scales acute, the lower unequal, 3-nerved, glabrous, rough on the keel, the first shorter than the second; flowering scales about 2" 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.

Illinois to Minnesota and Tennessee.

17. Poa Brachyphylla Schult. Short-Leaved Spear-Grass

Fig. 620

Poa brevifolia Muhl. Gram. 138. 1817. Not DC. 1806. Poa brachyphylla Schult. Mant. 2: 304. 1824.

Culms 1°-3° tall. Sheaths often shorter than the internodes; ligule 1/2"-1 1/2" long; leaves smooth beneath, rough above, 1"-2" wide, abruptly acute, those of the culm 1/2'-4' long, the uppermost sometimes almost wanting; basal leaves usually equalling or nearly as long as the culm; panicle 2 1/2'-5' in length, open, the branches ascending, widely spreading or often reflexed, 1 1/2'-3' long, spikelet-bearing at the ends; spikelets 3-6-flowered, 2i"-3i" long; empty basal scales unequal, acute, glabrous, the lower 1-nerved, the upper 3-nerved; flowering scales slightly webbed at the base, 2"-2V' long, obtuse, 5-nerved, the keel and marginal nerves sparingly pubescent, the intermediate nerves prominent, naked.

In rocky woods, southern New York to Illinois, Georgia and Tennessee. April-June.

18. Poa Cenisia All. Arctic Spear-Grass

Fig. 621

Poa cenisia All. Auct. Fl. Ped. 40. 1789.

Smooth and glabrous, culms 4'-15' tall, erect, slender, simple. Sheaths shorter than the internodes; ligule 1" long or less, truncate; blades 1'-4' long, 1/2"-1" wide; panicle 1'-4' in length, open, the branches generally widely spreading and more or less flexuous, l'-2 1/2' long; spikelets 3-5-flowered, 2 1/2"-3 1/2" long; lower scales acute or acuminate, 1-3-nerved; flowering scales about 2" long, faintly 5-nerved, the nerves short-pilose on the lower half, minutely pubescent between the nerves, somewhat webbed at the base.

Greenland and Labrador to Alaska, south in the higher peaks of the Rocky Mountains to Colorado. Also in Europe. Summer.