Fo. 7. 

 ARISTIDA CALIFORNICA Tkurb. Bot. Cal. ii. 289. 



Plant apparently annual in sandy soil and. perennial in rocky soil, tufted with 

 coarse roots. 



Culm geniculate, spreading or nearly erect, slender, repeatedly branched, clothed 

 with short, dense pubescence and villous at the nodes or smooth, 6 to 12 inches high. 



Leaves from the base numerous, with scarious, overlar^ping sheaths and short, 

 flat or convolute blades. Leaves of culm 3 or 4; sheaths striate, smooth, shorter than 

 the internodes ; blades convolute, slender, sharp-pointed, hispidulous below, minutely 

 pubescent above, i to 2 inches long. 



Inflorescence a slender raceme of 8 to 15 appressed spikelets, lower ones in twos, 

 one sessile and one pedicellate. 



Spikelets 1-flowered, 6 to 7 lines long; empty glumes linear-lanceolate, lacerate at 

 the apex, usually purple with white scarious margins, smooth or minutely hispid on 

 the keel; first glume 3£ to 4 lines long; second glume 6 to 7 lines long; stipe slender, 

 nearly a line long; awn articulated, deciduous, hispid, usually purple, common stalk 

 twisted, J to | inch long, branches slender, divergent, equal, 1 to 1£ inches long; palet 

 inconspicuous, less than i line long; grain narrow, cylindrical, light yellow, opaque, 2 

 to 2^ lines long. 



Plate VII ; a, spikelet enlarged to twice its real size ; b, empty glumes ; c, floret ; 

 dj floret and base of awn much enlarged. 



Southern California and Arizona. This species is evidently a perennial in clefts 

 of rocks and in protected places in the mountains, and quite as evidently an annual 

 in regions of loose sand. An extreme variation of this latter form is A. Californica 

 Thurb. var. fugitiva Vasey, which differs from the type chiefly in the shorter inter- 

 nodes, more abundant short branches, giving it a densely bushy form, looser panicle of 

 fewer spikelets and longer empty glumes (7 to 9 lines). The roots having but a slight 

 hold in the sand it is torn up and driven across the plains by the wind like a tumble- 

 weed. 



