No. 35. 
BOUTELOUA ARISTIDOIDES Thurber. 
Plant annual. 
Culms erect or decumbent, frequently geniculate and branching, slender, grow- 
ingin clusters, very variable in development, often fruiting when a few inches high, 
sometimes reaching 2 feet in height. 
Leaves with blades varying with the size of the plant from 1 to3 or 4inches in 
length, very narrow, erect, finely pointed ; sheath short, striate, smooth except a 
few long hairs at the top; ligule a short, ciliate ring. 
Panicles racemose, terminal and lateral, mostly 2 to 4 inches long, and consist- 
ing of 10 to 12 narrow, nearly sessile flower-spikes, these generally one-sided, in 
age spreading or horizontal, or even reflexed. Spikes + to ¢ inch long, on short 
hairy pedicels; each spike with 2 to 4 closely appressed spikelets, lowest with- 
out the imperfect flower and pedicel. 
Spikelets 3 lines long. 
Lower empty glume linear or awl-shaped, one-half as long as the stouter upper 
one ; this 3 lines long, 1-nerved, somewhat pubescent on the back ; flowering glume 
linear-lanceolate, acuminate, 3-nerved, 3-toothed at the apex. 
Palet a little shorter, 2-nerved, 2-toothed. Rudimentary flower consisting of 
3 long awns on a short pedicel, wanting in the lower spikelet. 
PLATE XXXV; a, spike; b, empty glumes; ¢, flowering glume; d, flowering 
glume of the lowest spikelet; e, palet ; f, rudiment. 
This species springs up in great abundance after the summer rains, and for a 
short time furnishes a large amount of food for stock on the ranges. 
It is one of 
_the so-called six-weeks grasses. 
