A(Ji{()STii)K.K. 8:i7 



There are about 120 apocioa widely spread over the warmer ami 

 tenii>erate regions of both the Eastern and the Western llemi- 

 8j)heres, hcin;,' particularly numerous in the Andes of South Arneriea. 



IJentham says: •'They are frefpiently regarded as forming a 

 Bection of .ir/rox/is, from wliich they dilTer ehirlly in the more 

 developed jialoa and the usual presence of the hristlo contimiing 

 tlie rachis of the spikelet, whilst fdliers again refer /hi/fiuia to 

 the supposed distinct tribe Arvn<lliie(r, on account of the hairs 

 8urrou!iding the flowering glume. But these hairs are ])resent in 

 almost all sju'cies of Aymslis." 



The northern species diller from Af/rosfis in the prolongation 

 of the rachilla into a bristle or stipes, usually, but not always, 

 hairy, in the larger spikelcts. with the palea nearly as long as the 

 glume, and the usually hair\ racjliilla. 



Hentham still retains the genus ('((hoinif/nis/is Adans. for 

 some 5 speiries, none of which are fouiul in North Ai>ierica. 



Ilackel places /)('i/en.i'ia as a setstion of ('((Utmiif/roslis, 



A. Leaf-blades involute, setaceous or rigid (a,) 



a. rani(;le thin, 4-" cm. h»ng, i)urple, spikelcts ;5.5 mm. 



long' I 



a. Panicle thin, 6-1".' cm. long, whitish, spikelcts (J-i mm. 

 long o 



a. Panicle thin. 10-1,') cm. long, spikelcts 4 mm. long. . 3 



a. Panicle thin, 10-14 cm. long, spikelcts ,').5 mm. long. 4 



a. Panicle rather close, 8-10 cm. long, Ihu' pubescence at 



the base of the blade, liglit green, spikelcts 3-4 mm. 



long 5 



a. I'anicle dense, 7-10 cm. long, fine wool at the base of 



the blades; spikelcts 4 mm. long (5 



a. Panicle dense, blades scabrous, 5-8 cm. long; spike- 



lets 4-4.7 mm. long 7 



B. Leaf-blades Hat or sometimes involute (b) 



b. JJase of the blades softly woolly; panicle open, thin, 

 whitish 8 



b. No soft wool at the base of the blade; a ring of short 

 hairs in 11 (e) 



