760 GRAMINE^E POA 



lanceolate 3-4 flowered, about 4 lines long : empty glumes smooth, unequal, 

 the lower lanceolate or broader, acute or acuminate, 1-nerved, 1 line long; 

 the upper broadly ovate, acute, 3-nerved, about 1^ lines long: flowering 



flumes 5-nerved, rough-hispid on the back, oblong-elliptical, obtuse, about 

 lines long: palets a little shorter than ibe glumes, ciliate on the keels, 

 the apex bidentate. In open places in timberland, eastern Washington to 

 Colorado. 



P. conflnis Vasey Grasses Pac. Slope, ii, 65. A cespitose imperfectly 

 dioecious perennial, with long running rootstocks: stems erect, slender, 

 4-12 inches high, smooth : sheaths shorter than the internodes, open above : 

 ligules a line long to obsolete : leaves of sterile, shoots numerous with smooth 

 se-arious-mar^ined sheaths and involute blades 2-6 inches long, about % 

 line wide : panicle oblong, 1-2 inches long its scabrous, branches in threes, 

 twos or solitary, 1 inch long or less : spikelets slightly compressed, 2-3 lines 

 long, 3-6-flowered: empty glumes broadly ovate, acute, 1-nerved, nearly 

 smooth, 1-1 3^> line* long, the second slightly longer but neither equalling 

 the first floret : flowering glumes broadly ovate, acute, not webbed, 5-nerved, 

 about 1)4 lines long: palets ovate-oblong pubescent on the keels: stamin- 

 ate flowers with abortive ovaries, and pistillate flowers with imperfect 

 stamens. On sandy ground along the coast, Oregon to Alaska. 



P. flava L. Sp. 68. P. serotina Ehrh. Stems slender, simple or 

 rarely branched, smooth, l>-5 feet long: sheaths usually shorter than 

 the internodes, smooth : ligules 1-2 lines long: leaves 2-6 inches long, 1-2 

 lines wide, smooth or rough: panicle 6-14 inches long, open, the branches 

 spreading or ascending, 2-5 inches long: spikelets 3-5-flowered, 1K~ 2 lines 

 long: empty glumes rough above on the keels, the lower usually 1-nerved; 

 the upper three-nerved : flowering glumes obtuse, somewhat webbed at 

 base, 1-1./4 lines long, silky-pubescent on the lower half of the marginal 

 nerves and the midnerve. In moist meadows, Oregon to Brit. Columbia 

 and Illinois : also Europe and Asia. 



P. nemoralis L. Sp. 69. Stems slender, 6-24 inches high, erect, sim- 

 ple smooth : sheaths usually shorter than the internodes : ligules %-\ line 

 long, truncate : leaves 1-4 inches long, 1 line wide or less, smooth or rough : 

 panicle 2-5 inches long, open, its branches erect or ascending 1-2 inches 

 long: spikelets 2-5-flowered l>-2) inches long: empty glumes acute; or 

 acuminate, 1-3-nerved : flowering glumes obtuse or acute, l-l/ lines long, 

 faintly 5-nerved, somewhat webbed at the base, the middle and marginal 

 nerves silky on the lower half. Eastern Washington to the Eastern States. 



P. GLADCA Vahl Fl. Dan. t. 964. Stems erect, 6-24 inches high, rigid, 

 glabrous and somewhat glaucous ;. sheaths longer than the internodes : 

 ligules 1 line long : leaves 1-2 inches long, 1 line wide or less, smooth be- 

 neath, scabrous above : panicle 1-4 inches long, open, with erect, or ascend- 

 ing branches 6-18 lines long : spikelets 2-4-flowered, 23^-3 lines long : empty 

 glumes acute, 3-nerved, glabrous, rough on the upper part of the keel: 

 flowering glumes 1)^-1% lines long, obtuse or acutish, rough, not webbed 

 at the base, the lower part of the midnerve and marginal nerves silky-pub- 

 escent. Oregon to the Rocky mountains and Maine : also in Europe. 



P. laxa Hsenke Sudet. 118. Stems 6-12 inches high, erect: sheaths 

 often longer than the internodes: ligules about 1 line long: leaves 1-3 

 inches long, >-! line wide, acuminate : panicle 1-4 inches long, its bran- 

 ches usually erect, sometimes ascending, 1 inch long or less : spikelets 3-5- 

 flowered, 2-2% lines long: empty glumes usually 3-nerved acute, glabrous, 

 rough on the keel at the apex : flowering glumes l%-l% lines long, obtuse, 

 3-nerved, or sometimes with an additional pair of obscure nerves, the 

 midnerve pilose on the lower half, rough above ; the lateral ones pilose 

 below. Washington to Alaska and across the continent : also in Europe. 



