No. 41. 

 BOUTELOUA OLIGOSTACHYA Torrey. 



Culms csespitose from a short thick rootstock extending into a thick close 

 mat, slender, smooth, erect, 1 to 2 feet high. 



Leaves mostly near the ground; blade short, curled, in moist situations 

 becoming slender and longer, very narrow, attenuate into a slender point; sheath 

 shorter than the internodes, close; ligule very short, ciliate. 



Inflorescence consisting of 1 to 3 spikes, densely crowded with flowers on one 

 side of the rachis, 1 to 1-J inches long, usually becoming curved and spreading; 

 rachis narrow and sparsely pubescent. 



Spikelets very numerous (often 50 or more), in 2 rows on one side of the 

 rachis, nearly at right angles with it, sparsely pubescent, sometimes sparsely glan- 

 ular on the keel, about 3 lines long, containing 1 perfect flower and 1 rudimentary 

 one. 



Empty glumes unequal, awn -pointed; lower one-half to two-thirds as long as 

 the upper, thin; upper 2| to 3 lines long, purplish; flowering glume lanceolate, 3 

 lines long, including the awns, hairy on the back, lobed to or nearly to the middle, 

 middle lobe broad, lateral ones very narrow, all terminating in sharp awns. 



Palet nearly equal in length to the flowering glume, narrower, 2-toothed at 

 the apex, 2-nerved. Imperfect flower reduced to 3 equal awns, with 1 or 2 scales 

 at the base, on a short pedicel having a tuft of white hairs at the top. 



Plate XLI: land 2, typical plant; 3, larger form; a, empty glumes; b, perfect 

 and imperfect flowers; c, flowering glume, from the back. 



This species is probably more widely spread than any other of the family, and is 

 the one which constitutes with the buffalo grass (Buchloe dactyloides) the main 

 vegetation of the vast plains of the West. 



