298 OHIO BIOLOGICAL SURVEY 



whose rachis is bifid at the apex. Spikelets 4-12 on each branch ; 

 lemma scabrous, ending in 3 short awns ; sterile lemma with 2 acute 

 lobes and 3 straight awns. 



A valuable hay and pasture grass. In dry soil. July-Sept. Lake, 

 Erie, Ottawa, Franklin, Adams. 



34. Bouteloua Lag. Mesquite-grass. 



Annual or perennial usually gray-green grasses with narrow, flat, 

 or convolute leaves and numerous spikelets in 1 -sided spikes. Spike- 

 lets 1-2-flowered, arranged in two rows on one side of a flat rachis 

 and bearing 1-3 awns and 1-3 rudimentary glumes; empty glumes 

 unequal, keeled ; lemma 3-5-nerved, 3-toothed, the teeth awn-pointed 

 or awned ; palet hyaline, 2-keeled, 2-toothed ; grain free. 



1. Rachilla glabrous; inner empty glume strongly papillose-hispid on the keel. 



B. Jiirsuta. 



1. Rachilla with a tuft of hairs; inner empty glume scabrous and sometimes 



sparingly long-ciliate on the keel. B. oligostachya, 



1. Bouteloua hir$uta Lag. Hairy Mesquite-grass. A gray- 

 green grass with erect stems y^-ly^ ft. high, leafy at the base, and 

 with an inflorescence of 1-4 erect or ascending spikes whose rachis 

 extends beyond the spikelets as a conspicuous point. Spikelets 

 numerous ; outer empty glume setaceous, the inner conspicuously 

 tuberculate-hirsute on the keel ; fertile lemma pubescent, 3-cleft, 

 the divisions aAvn-pointed ; rachilla without a tuft of hairs under the 

 vestigial glumes and awns. 



A valuable pasture grass in the West. In dry soil, especially on 

 prairies. July-Sept. Waifs in Franklin County. 



2. Bouteloua oligostachya (Nutt.) Torr. Smooth Mesquite- 

 grass. A gray-green grass with erect, simple stems, Vi-l 2 /^ ft. high 

 with involute curly leaves, and with an inflorescence of 1-3 spikes 

 often strongly curved, the rachis terminating in a short inconspicuous 

 point. Spikelets numerous, outer empty glume hyaline, shorter than 

 the membranous inner one which is scabrous and sometimes long- 

 ciliate on the keel or with a few papillae ; fertile, lemma pilose, 

 3-cleft, the divisions short-awned ; sterile lemma consisting of two 

 truncate lobes and three equal awns with a tuft of long hairs at the 

 base. 



A valuable pasture grass in the West. On dry prairies. Julv- 

 Sept. Waifs in Franklin County. 



