No. 41. 
BOUTELOUA OLIGOSTACHYA Torrey. 
Culms ceespitose 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 to14 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 
e. 
Empty glumes unequal, awn-pointed; lower one-half to two-thirds as long as 
the upper, thin; upper 24 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. 
PuLaTE 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 (Buchloé dactyloides) the main 
vegetation of the vast plains of the West. 
