614 POACE.^. 



Sheaths smooth or densely ciliate, ciliateat the throat; ligule 1-2 mm. 

 long ; blades of the culm 3-4 in number, smooth or scabrid or thinly 

 pubescent, 15-25 cm. long, 4-6 mm. wide. Panicle simple, very 

 variable, rays erect or the lower spreading, 15-30 cm. long, rays in 

 threes, fours, or fives, or tlie lowest and those above in twos, the 

 longest bearing 2-4 spikelets. Spikelets compressed, linear or oval- 

 lanceolate, 6-10-flowered, longest joint of rachilla 5 mm. long; 

 empty glumes smooth, compressed, oval-lanceolate, acute, first 5- 

 nerved, 11-13 mm. long, second 7-9-nerved, 13-14 mm. long; floral 

 glume oval-lanceolate, conduplicate, scabrous or pubescent, 9- 

 nerved, 15-17 mm. long, awn 5-12 mm. long, starting below the 

 entire apex of its glume;' palea linear, 13 mm. long, finely pecti- 

 nate-ciliate. 



Wyoming, Buffum 102; Washington, Siihsdorf; Oregon, HowelL 



British America to California. 



Var. minor Scribn. Macoun, Cat. 4: 238 (1888). 



Leaves finely pubescent, blades scarcely 3 mm. wide; panicle 

 thin, slender, with few spikelets. 



Arizona and Oregon. 



9. B. segetum H. B. K. Xov. Gen. et Sp. 1 : 152 (1815). 

 Annual; culms simple, erect, glabrous, 80-120 cm. high. 



Sheaths about the length of the internodes: ligule 2 mm. long; 

 blades 4 in number, flat, scabrous, 15-20 cm. long, 3-7 mm. wide. 

 Panicle simj^le, secund, nodding, about 30 cm. long, axis and 

 rays scabrous, the lowest lialf-whorl of rays 5 in number, the next 

 above fewer, 8-9 cm. distant, the longest 12-15 cm. long, bear- 

 ing about 3 spikelets near the apex. Spikelets scabrous, com- 

 pressed, linear-oblong, nearly 3 cm. long, 3-10-flowered, joint of 

 rachilla 2 mm. long, empty glumes linear-lanceolate, compressed, 

 first 5-nerved, about 10 mm. long, second 7-nerved and about 12 

 mm. long; floral glume oval-lanceolate, 7-nerved, about 14 mm. 

 long to the acute single joint, awn 5 mm. long, more or less; palea 

 concealed in the conduplicate grain. 



Introdu(^ed into California from Mexico and South America. 



10. B. barbatoides, Trisetum harhatutn Steud. Syn. PI. Gram.. 

 229 (1855). 



