GRASS FAMILY 



127 



7. Aristida reverchoni Vasey. 

 Reverchon's Aristida. Fig. 270. 



Aristida rczcichoni Vasey, Bull. Torrey Club 13: 52. 1886. 



Perennial ; culms densely cespitose, erect, 30-60 

 cm. tall ; lilades involute, more or less flexuous, as 

 much as 15 cm. long; panicle narrow, 10-15 cm. 

 long, the branches short, appressed ; glumes un- 

 equal, awnless, smooth, or the first scabrous on the 

 upper part of the keel, the first about 6 mm. long, 

 the second about 10 nun. long; lemma 10-12 mm. 

 long, smooth except the minutely pubescent callus, 

 narrowed above but not twisted ; awns equal, about 

 2 cm. long. 



Deserts and plains, Mojave Desert, east to Texas. May. 

 Type locality: Te.xas. 



8. Aristida purpiirea Nutt. 

 Purple Aristida. Fig. 271! 



Aristida purpurea Nutt. Trans. Am. Phil. Soc. II. 

 5: 145. 1837. 



Perennial; culms erect, about 60 cm. tall; 

 blades flat or involute, 5-12 cm. long; panicles 

 10-15 cm. long, rather loose; branches and 

 pedicels slender, more or less recurved ; 

 glumes unequal, smooth, short-awned, 1- 

 nerved. the first 6 mm. long, the second about 

 twice as long; lemma 12 mm. long, purple, 

 strongly scabrous in lines, the apex some- 

 what narrowed, flattened and slightly twisted; 

 awns equal, about 3 cm. long. 



Plains and deserts, southern California to Texas 

 and northern Mexico. Apr. -July. Type locality: 

 Texas. 



9. Aristida wrightii Nash. 

 Wright's Aristida. Fig. 272. 



Aristida ivrightii Nash in Small, Fl. Southeast. U. S. 116. 

 1903. 



Culms erect, 30-60 cm. tall, smooth ; sheaths 

 smooth, slightly villous at the throat, the collar 

 bearing a ciliate line ; blades involute, scattered ; 

 panicle narrow, 15-25 cm. long, the short stiff 

 branches appressed or ascending; glumes unequal, 

 the first about 10 mtn. long, the second about 15 

 mm. long : lemtna papillose-scaberulous, about 1 cm. 

 long; awns about equal, spreading, 15-25 mm. long. 



Deserts, plains, and rocky hills, Colorado Desert (Parish), 

 east to Texas and south to central Mexico. May. Type lo- 

 •;ality: Texas. 



