first glume 1.5 mm. long, with 2 })ristl('.s 3-3 mm. long, second 

 with un uwn 4 luiii. long; llonil gluniu t'llipliciii, hairy on the hack 

 near tiie margins; tiieawn 2 mm. long; paleu uwnless, ])nhescent on 

 the hacl<. \ cry variahie. 



Colorado, .fours j Arizoiui, Priinjli' in lS8-t; Mexico, Piihnii' 

 451). I'rinijh' 4'^G. 



On plains and foot-liills, a plant of some value furnishing con- 

 siderable [)astnre. mndi resend)ling timothy. 



V'ar. brevifolius (Scrihn.). //. Inrrlfoliiis Scribn. ined. 



Ijeaf-blades l-S cm. long. U.A-l..') mm. wide. 



Mexico, /'ri/it/h' 'U70, JMleri OHO. /'ahtier 48!). 



\'ar. glaucifolius nov. var. Glaucous, blades of sterile slioots 

 conduplicate, falcate, 1-5 cm. long, 'Z-'.i mm. wide, those of the 

 eulni 5 cm. long. 



Mexico, rriiiijle A'H\\ Texas, Ifavtinl, Xedllei/. 



54. (115). Peeeilema J. & C. Presl, lieliq. llauik. 1:233 

 (18:50). 



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

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

 not produced ahove the llower; sterile or stamiiuite s[»ikelets inli-r- 

 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 thehase; 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, (irain ovoid-ohlong, scarcely inclosed, but 

 free. 



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

 Panicles terminal, spikelike, continuous or interrupted. 



There arc three or four species belonging to tropical America 

 from Mexico to Brazil. Nearly allied to Midili'iiberr/ia, but with 

 the empty glumes awned as well as the floral one. 



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



The whole jdant light-colored. Culms slender, 50-80 cm. liigli. 

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

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



