234 A TEXT-BOOK OF GRASSES 
with their antrorsely scabrous awns are sharp-pointed so they 
readily penetrate clothing and the wool of sheep, because of which 
these species are considered a great pest. The following key will 
distinguish the common species: 
A. Panicle contracted, dense. 
B. Awn % inch long. 
c. Culm pubescent below panicle........... B. rubens L. 
cc. Culm glabrous below panicle............ B.madritensis L. 
BB. Awn about 14 inch long.. nae .......B. hordeaceus L. 
AA. Panicle open, the branches spreading. 
B. Awe twinted and bent 625 ess ees teins ans B. trintt Desv. 
BB. Awn not twisted and bent. 
GET OH SITOOEH Ne oil's 028 oie hina 3 dd B. secalinus L. 
cc. Sheaths pubescent. 
p. Awn 11% to 2 inches long.............. B. villosus 
pp. Awn not over % inch long. [Forsk. 
mu, First plume J-neryed.:......5...5.- B. tectorum L. 
EE. First glume 3-nerved. 
¥r. Lemmas pubescent............--- B. arenarius 
[Labill. 
rr. Lemmas glabrous.............-.- B. pratense 
