80 POACEAE 



lemma about 5 mm. long, acute, scarious at the apex, finely scabrous-puberu- 

 lent. Canons: B.C. Ida. Ore. Submont. Mont. My-Je. 



43. P. epilis Scribn. Stem 4-6 dm. high; leaf-blades smooth, 2-20 cm. long, 

 flat, or involute when dry; panicle dense, oblong, 3-7 cm. long; spikelets 3-4- 

 ilowered, about 5 mm. long; empty glumes smooth, unequal, the first 2.5 mm. 

 long, the second 3 mm. long; lemma about 4 mm. long. Mountains: Mont. 

 Colo. Utah B.C. Mont. Alp. 



44. P. scaberrima Rydb. Stem 3-5 dm. high, 2- or 3-leaved, glabrous; 

 blades of the basal leaves 8-15 cm. long, less than 1 mm. wide; those of the stem- 

 leaves 1-5 cm. long, erect; panicle elliptic, dense, 4-7 cm. long; spikelets about 

 1 cm. long; empty glumes ovate, nearly equal, 4-5 mm. long, glabrous; lemma 

 ovate, acuminate, pale, slightly tinged with purple, 5-6 mm. long, strongly 

 5-nerved, and conspicuously scabrous. Hills: Ida. Submont. Je. 



45. P. nematophylla Rydb. Stem about 3 dm. high; basal leaf-blades 1-1.5 

 dm. long, less than 0.5 mm. wide; stem-leaves few, near the base; blades 3-5 cm. 

 long; spikelets 7-9 mm. long; empty glumes about 4 mm. long, lanceolate, glab- 

 rous and shining; lemma about 6 mm. long, light green, with a silvery scarious 

 margin. Mountains: Colo. Utah. Submont. JeAu. 



46. P. subaristata Scribn. Stem 1-4 dm. high; leaf-blades 5-10 cm. long, 

 0.5-1 mm. wide, strongly involute, scabrous; panicle oblong, dense, 3-6 cm. long; 

 spikelets 4-7-flowered, 6-9 mm. long; empty glumes subequal, 5 mm. long, 

 lanceolate, 1-nerved; lemma 6 mm. long, scabrous, acuminate or even cuspidate. 

 High mountains: Sask. Wyo. Ida. Alta. Mont. Alp. My-Au. 



47. P. idahoensis Beal. Stems 3-6 dm. high; ligules acute; basal leaf- 

 blades filiform, 1.5-2.5 dm. long, flaccid, involute; those of the stem-leaves 2-5 

 cm. long, erect; panicle loose, flexuose, 7-10 cm. long; spikelets compressed, 6-10 

 mm. long, loosely 5 7-flowered; empty glumes nearly equal, acute, broadly 

 scarious-margined, about 4 mm. long; lemma scarious at the apex, minutely 

 scabrous throughout*. P. filifolia Vasey, not Schkuhr. P. scabrifolia Heller. 

 Rocky banks: Ida. Mont. Ore. Submont. Ap-Je. 



48. P. gracillima Vasey. Stems 3-5 dm. high, slender, erect; blades of the 

 basal leaves filiform, flaccid, spreading, 5-12 cm. long; those of the stem-leaves 

 2-5 cm. long; panicle 5-10 cm. long, open; spikelets 6-8 mm. long, about 5- 

 flowered, lax; empty glumes ovate-lanceolate, acute, unequal; lemma 4-5 mm. 

 long, acute, purplish, scarious at the apex, more or less scabrous and somewhat 

 pubescent on the keel and marginal nerves. Mountains: B.C. Calif. Mont. 

 Alta. Jl-Au. 



49. P. Vaseochloa Scribn. Stems slender, 0.5-1.5 dm. high, 1-2-leaved; 

 basal leaves filiform, with thickened bases; panicle 3-5 cm. long; spikelets pur- 

 plish, 6-8 mm. long, 3-5-flowered; empty glumes scarious-margined, 2-3 mm. 

 long; lemma about 4 mm. long, finely scabrous on the keel and veins. P. pul- 

 chella Vasey. River banks: Wash. Alta. Ida. Ore. Submont. Mont. Ap- 

 Jl. 



50. P. longiligula Scribn. & Williams. Stem 3-5 dm. high, with numerous 

 persistent basal sheaths; blades of sterile shoots 1.5-2.5 dm. long, 1-2 mm. wide, 

 flat or conduplicate; those of the stem-leaves shorter; panicle 6-12 cm. long; 

 spikelets 4-6-flowered, 6-10 mm. long; lemma 4-5.5 mm. long, scabrous on the 

 back, villous on the keel and marginal nerves below. Hillsides and plains: S.D. 

 N.M. Calif. Ore. Son.Subalp. My-Jl. 



51. P. scabriuscula Williams. Stem 2.5-3 dm. high, smooth; blades of 

 the sterile shoots 8-12 cm. long, 1-1.5 mm. wide, flat or convolute; those of the 

 upper stem-leaves seldom over 1 cm. long; panicle open, subpyramidal, 5-7 cm. 

 long, 2-3.5 cm. broad; spikelets 5-7 mm. long; lemma oblong, obtuse, keeled, 

 pale green or purplish, about 3.5 mm. long. Mountains: Utah Colo. My-Je. 



52. P. longipedunculata Scribn. Stem smooth, 5-7 dm. high; blades of 

 the sterile shoots 5-20 cm. long, 1-2 mm. wide, involute; those of the stem-leaves 

 1-3 cm. long, scabrous; spikelets green or tinged with purple, 6 mm. long; lemma 



