374 



CONTRIBUTIONS PROM THE NATIONAL HERBARIUM. 



long, the latter slightly pubescent above; caryopsis about 1.5 to 2 mm. long, 0.5 mm. 

 wide, oval, more or less pointed at both ends, the seutellum covering nearly the entire 

 ventral surface and the embryo extending nearly to the apex. (Figure 34.) 



The distribution of this species is very wide, from British Columbia southward 

 through the continental highland and again at points along the Gulf coast in Florida. 

 As in the case of B. gracilis the northern and southern forms differ widely in both 

 habit and general aspect, the northern being shorter as a rule and showing a tendency 

 to form a sod, while the southern is in the strictest sense a bunch grass. It reaches its 

 best development upon stable, sandy-loam soils and extends in New Mexico and 

 Arizona into the upper foothills. The most abundant development that has been met 



Fig. 34. — Bouteloua hirsuta. a, Spikelet; 6, c, lemma and palet of first floret; d, rudi- 

 ment; e, two views and cross section of caryopsis. a, Scale 7.5; b-e, scale 12.5. 

 From Griffiths 6125. 



with is in the sandy lands of the Texas-New Mexico line east of Roswell and in foot- 

 hills from Arizona south. In the former situation this and two or three species of 

 Andropogon constitute about the only forage. It also grows almost to the exclusion 

 of all else in localities upon the plateau of central Mexico. 



The species is well understood and seldom incorrectly named in collections. Its 

 distinguishing characteristics are the prolongation of the rachis beyond the spikelets, 

 the tuberculate, hairy glumes, and the more or less papillose-hairy leaf margins. 

 Heller 1878, Lemmon 3175 and 4673, Pringle 409, and Pal are typical. Clem- 



ents's no. 1 (Manitou, Colorado) and Rydberg's no. 1552 an } spiked forms which are 

 common enough, but not so commonly collected. 



