218 POACE.E. 



the gliime, capillary awn 12-18 cm. long, the base abruptly 

 pointed. Anthers linear. 1 mm. long, apex pencil-tufted. 



Mexico, Pringh -4281; also in Western Soutli America. 



Cool ledges. 



9. S. setigera Presl, Eeliq. Hank. 1:226 (1830). 



A rather stout and often scabrid grass, 30-90 cm. high; culms 

 often pubescent at the nodes. Sheaths hairy at the throat, the lower 

 shorter than the internodes; ligule truncate, 2 mm. long; blades of 

 sterile shoots mostly involute, one-third as high as the culms, tliose 

 on the culm 2-3 in number, often flat, 4-6 mm. wide, the upper 

 one 15-30 cm. long. Panicle mostly included at the base by the 

 loose sheath, flexuose, somewhat one-sided, 12-30 cm. long, the rays 

 slender in pairs. Empty glumes subequal or the upper shorter, 

 long-acuminate, S-uerved, second glume sometimes with several 

 finer intermediate nerves, 16-20 mm, long; floret 10 mm. long, 

 silky hairy on the nerves, the callus curved and sharp, a crown of 

 hairs at the apex, awn geniculate, above the middle bent again, 

 twisted and pubescent below, 6-10 em. long. Anthers bearded at 

 the apex. A common l)unch-grass on tlie dry hills. 



California, PringJe, Jones; also in Kansas. 



Kansas, Texas. New Mexico, Utah, California and Oregon. 



10. S. avenacea L. Sp. PI. 78 (1753). Black Oat-grass. S. 

 harhda Michx. Fl. Bor. Am. 1:53 (1803). S. Virginica Pers. 

 Syn. 1: 99 (1805). S. licolor Pursh, Fl. Am. Sept. 73 (1814). 



Culms slender, 40-00 cm. high. Sheaths half as long as the 

 internodes; blades filiform, the largest when spread scarcely 2 mm. 

 wide, those of the sterile shoots about half as long as the culm, 

 those on the culm 3 in number, the upper 4-7 cm. long. Panicle 

 much exserted, open, 12-20 cm. long; rays very slender, mostly 

 in twos, the largest 6 cm. long, including the two branches, each 

 2-3 cm. long, bearing a single flower. Empty glumes wliitish, 

 subequal, linear-lanceolate, 5-nerved. 10-13 mm. long; floret 

 brown, scabrid, 9-10 mm. long, including the sharp curved callus, 

 the apex bearing a short crown of hairs, and an awn 4-6 cm. long, 

 once or twice bent above the middle. 



