No. 7. 

 ARISTIDA CALIFORNICA Tlmrl.. P.ol. (';.l. ii. 2S9. 



Plant apparently annual in sandy soil :iii(l perennial in rocky soil, tufted with 

 (^oarse roots. 



Vulm geniculate, spreading or nearly erect, slender, re])eati'dly branched, clothed 

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



Leaves from the base numerous, with scarious, overlapping sheaths and short, 

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

 the internodes; l)lad('S convolute, slender, sharp jtointed, his])idulous below, minutely 

 I)ubesceut above, A to 2 inches long. 



Inflorescence a slender raceme of .s to 1 "> api)ressed si)ikelets, lower ones in twos, 

 one sessile and one pedicellate. 



Spikclets IHowered, 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 3i to 4 lines long; second glume C> to 7 lines long; stipe slender, 

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

 twisted, i to f inch long, branches slender, divergent, equal, 1 to IJ inches long; palet 

 incons])icuous, less than J line long; grain narrow, cylindrical, light yellow, opaque, 2 

 to 2:^ lines long. 



Plate VI I ; a, si)ikelet enlarged to twice its real size ; b, empty glumes ; c, floret ; 

 d, floret and base of awn much enlarged. 



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

 of rocks and in ])rotected places in the mountains, and quite as e\idently an annual 

 in regions of loose sand. An extreme variation of this latter form is ^l. Cali/'oruica 

 Thurb. var. fugitlrn Vasey, which difters from the type chiefly in the shorter iiiter- 

 7U)des, more abundant short branches, giving it a densely hushy foiin, looser panicle of 

 fewer spikelets and longer empty glumes (7 to !• 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. 



