DESCBIPTIONS OF TRIBES AND GENERA. 



3 31 



177. (177) Gymnopogon Beauv. (Anthopogon Nutt., 

 Dichcetaria Nees). Flowering glume a little broader 

 than the empty glumes, awued below the two-cleft apex ; 

 sterile glumes often reduced to awns ; spikes delicate, at 

 first erect, finally divaricate-spreading or reflexed. 



Species six, all, except one in Ceylon, American. 

 Leaves short, rather broad and rigid. 



178. (178) Monochaete Doll. Like the preceding, but 

 the rachilla is not produced beyond the flowers ; spikes 

 many, densely flowered. 



Species one (31. fastigiata Doll.), in Brazil. 



179. (179) Schedonnardus Steud. Spikes loosely flow- 

 ered, remote on a common ra- 

 chis, spreading ; flowering glume 

 finall}- indurated, linear, acuminate- 

 pointed. 



Species one (Sch. Texanus 

 Steud.), in N. America. 



180. (180) Craspedorhachis Benth. 

 Like the preceding, but the flower- 

 ing glume and palea are very deli- 

 cate, and so small as to appear like 

 minute scales. 



Species one (C. Africana 

 Benth.), in tropical Africa. 



181. (181) Bouteloua Lagasca 

 (Eutriana Trim, Actinochloa Willd.) 



(Fig. 70). Spikes Vei'V Variable, FlG - 70.—Bouteloua racemosa 

 v & . ' ... i , La £- (After Asa Gray, Man. 



sometimes consisting ol many and p>- 9-) 

 sometimes of 1-3 spikelets ; in the latter case they re- 

 semble solitary spikelets, but are distinguished by the 

 prolongation of the axis beyond the spikelets ; flowering 

 glumes with 3-5 teeth, of which 1-3 bear awns or mucros ; 

 upper sterile glumes usually reduced to awns. 



Species about thirty, especially abundant upon the 

 plateaux of the southwestern United States, where they 

 form a large part of the prairie-grass ("Mesquite" or 

 " Grama grass") and furnish excellent grazing for stock. 



Sec. I. Chondrosium Desv. (as a genus). Spikelets 

 pectinate, numerous in each of the more or less falcate 



