AGROSTIDE^, 271 



first glume 1.5 mm. long, with 2 bristles 2-3 mm. long, second 

 with an awn 4 mm. long; floral glume elliptical, hairy on the back 

 near the margins; the awn 2 mm. long; palea awnless, pubescent on 

 the back. Very variable. 



Colorado, Jones; Arizona, Pringle in ISSi; Mexico, Palmer 

 459, Pringle 426. 



On plains and foot-hills, a jilant of some value furnishing con- 

 siderable pasture, much resembling timothy. 



Var. brevifolius (Scribn.). L. Ircvifolius Scribn. ined. 



Leaf-blades 1-8 cm. long. 0.5-1.5 mm. wide. 



Mexico, Pringle 2470, Botteri 680, Palmer 489. 



Var. glaucifolius no v. var. Glaucous, blades of sterile shoots 

 conduplicate, falcate, 1-5 cm. long, 2-3 mm. wide, those of the 

 culm 5 cm. long. 



Mexico, Pringle 426; Texas, Havard, Nealley. 



54. (115). Pekeilema J. & C. Presl, Reliq. Hsenk. 1:233 

 (1830). 



Spikelets 1-flowered, borne on short spikes, which are branches 

 of the main dense spike; rachilla articulate above the empty glumes, 

 not produced above the flower; sterile or staminate spikelets inter- 

 mixed with the fertile ones. The 2 outer empty glumes delicately 

 hyaline, keeled, the nerve produced into a long slender awn, some- 

 times short or very short awns at the base; floral glume hyaline, 

 3-nerved, apex entire or 2-toothed, the awn much longer than 

 those on the empty glumes; palea hyaline, 2-keeled. Stamens 3. 

 Styles short, distinct. Grain ovoid-oblong, scarcely inclosed, but 

 free. 



Annual tufted or diffuse grasses, with narrow flat leaf-blades. 

 Panicles terminal, spikelike, continuous or interrupted. 



There are three or four species belonging to tropical America 

 from Mexico to Brazil. Nearly allied to Mvlilenhergia, but with 

 the empty glumes awned as well as the floral one. 



1 . P. crinitum J. & C. Presl, 1. c. 



Tlio whole plant light-colored. Culms slender, 50-80 cm. high. 

 Sheaths scaberulous; ligule less than 1 mm. long, ciliolate; blades 

 thin, narrow at the base, 10-15 cm. long. Empty glumes oval. 



