120 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



idal, 15 to 20 cm. long, the branches 

 in distant whorls of 2 to 5, spreading, 

 naked on the lower half or two- 

 thirds; spikelets 2- or 3-flowered; 

 lemmas about 3.5 mm. long, oblong- 

 lanceolate or the upper lanceolate, 

 webbed at base, villous on keel and 

 marginal nerves, and more or less so 

 on the internerves below, the inter- 

 mediate nerves distinct. 21 

 Known only from Raton, N. Mex. 

 May be a form of P. occidentalis. 



Figure 143.- 



-Poa tracyi. Panicle, X 1; floret, X 10. 

 (Type.) 



30. Poa sylvestris A. Gray. (Fig. 

 144.) Culms tufted, erect, 30 to 100 

 cm. tall; sheaths glabrous or rarely 

 pubescent, the lower usually antrorse- 

 ly scabrous; ligule about 1 mm, long; 

 blades lax, 2 to 6 mm. wide; panicle 

 erect, 10 to 20 cm. long, much long- 

 er than wide, the slender tlexuous 

 branches spreading, usually 3 to 

 at a node, the lower usually reflexed; 

 spikelets 2- to 4-flowered, 3 to 4 mm. 

 long; lemmas 2.5 to 3 mm. long, 

 webbed at base, pubescent on the 

 keel and marginal nerves and more 

 or less pubescent on the internerves. 

 91 -Rich, moist, or rocky woods. 

 New York to Wisconsin and Nebras- 

 ka, south to Florida and Texas. 



Sheaths pubescent in a specimen from 

 St. Louis, Mo. 



31. Poa reflexa Vasey and Scribn. 

 Nodding bluegrass. (Fig. 145.) 

 Culms solitary or in small tufts, 

 erect, 20 to 40 cm. tall; blades rather 

 slant, I to 4 mm. wide; panicle 

 nodding, 5 to 15 cm. long, the 

 branches naked below, solitary, in 

 pairs or in threes, the lower usually 

 reflexed, sometimes strongly so; spike- 

 lets 2- to 4-flowered; lemmas about 



Figure 144. — Poa sylvestris. Panicle, X 1; floret 

 X 10. (Wheeler 6, Mich.) 



3 mm. long, oblong-elliptic, webbed 

 at base, villous on keel and marginal 

 nerves, sometimes on intermediate 

 nerves. QJ. — Open slopes and al- 

 pine meadows, 2,000 to 4,000 m., 

 Montana to eastern British Columbia, 

 south in the mountains to New- 

 Mexico and Arizona. 



32. Poa wolfii Scribn. (Fig. 140.) 

 Culms tufted, erect. 40 to SO cm. 

 tall; sheaths slightly scabrous; blades 

 crowded toward the base of the 

 culms, mostly 1 to 2 mm. wide; 

 panicle drooping, S to 15 cm. long, 

 the branches ascending, bearing a few 

 spikelets toward the ends, the lower 

 mostly in pairs; spikelets 2- to 4- 

 flowered, 5 to 6 mm. long; lemmas 



