216 POACK.E. 



tlio lower liiilf, smooth uhovcs except u sliort thin row of luiirrt, the 

 nUlus hunl, aeiuninute, iiwn !)-17 cm. long, usually witii two bomU 

 uuur tho middle;, uhout 2 cm. distant. 



Illinois, Clark 1!K)» from Uchh, hval 41; Iowa, I'. S. Dept. 

 Agricul. 2S',*, from ,/. (-\ Arthur ; liritish Columbia, Mavnun. 



The long awns when alteriuitely wet and dried bore their way 

 for several inches into tho sand. They nuiy also penetrate the llesh 

 of sheep and dogs, causing much annoyance and even death. 



Sandy oak-land or prairies; Mi(!higan, Illinois, to California. 



6. S. oomata Trin. & Kupr. Mem. Acad. St. I'etersb. (VI.) 6: 75 

 (1843). HuNcii-(fu.\88. 



A rather stout and usually scabrous grass. 30-120 cm. high. 

 Sheaths mostly shorter than the internodes; ligule acute. 3-4-0 

 mm. long; leaves of sterile shoots a fourth to half the length of the 

 culm, tliosoof the culm 'l-b in number. Panicle partially included, 

 open, 20-30 cm. long, rays distant in twos or threes, few-flowered. 

 Empty glumes nearly equal. 5-nerved. 20-30 mm. long including 

 the long slender point; floret pubescent with no crown of hairs at 

 the apex. 10-13 mm. long including a long sharp callus, awn ob- 

 scurely twice bent below, and variously curled and twisted above. 

 10-15 cm. long, sparsely pubescent to the second bend, shining 

 above or minutely pubescent; palea as long as itt: glume. Sta- 

 mens 3. 



(y'olorado, U. S. Dept. Agricul. 208; Oregon, Howell; Montana, 

 Anderson. 



Found along the Rocky Mountains, furnishing considerable 

 pasture. 



6. S. mucronata H. B. K. Nov. Gen. et Sp. 1: 125 (1815). 



A tufted erect perennial, 40-00 cm. high. Leaves of sterile 

 sboots numerous, ligule a ring with very short hairs; blades con- 

 duplicate, 5-10 cm. long, 0.0 mm. diam., those of the culm 2 in 

 number; upper ligule oblique, adherent, very short; blades 3-0 

 cm. long. Panicle exserted, simple, narrow, interrupted, 8-13 

 cm. long, rays in twos to fours, the longest 3-4 cm. loTig, bearing 

 3-4 spikelets on the outer half. Spikelets purplish brown, empty 

 glumes chartaceous, linear-acute, subequal, 5-0 mm. long, 3-nerved, 



