No. 35. 

 BOUTELOUA ARISTIDOIDES Thurber. 



Plant annual. 



( 'vims erect or decumbent, frequently geniculate and branching, slender, grow- 

 ing in 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 to 3 or 4 inches 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 f inch long, on short 

 hairy pedicels ; each sjjike with 2 to i 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 ; c, flowering glume; d, flowering 

 glume of the lowest spikelet; e, palet ; /, 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. 



