GRASS FAMILY 



1. Aristida calif ornica Thurb. 



California Aristida. 



Fig. 264. 



Thurb. in S. Wats. Bot. Calif. 

 U. S. Nat. Herb. 3: 

 Contr. U. S. 



Aristida calif ornica 



2: 289. 1880. 

 Aristida jonesii Vasey, Contr. 



48. 1892. as synonym. 

 Aristida califoritica fugitiva Vasey, 



Nat. Herij. 3: 49. 1892. 



Perennial ; culms cespitose, wiry, much 

 branched above base, 15-30 cm. tall, crisp- 

 pubescent : blades short, involute, sharp- 

 pointed. 1-4 cm. long; panicles numerous, 

 loose, 2-5 cm. long, the few branches few- 

 flowered : glumes smooth or the first slight- 

 ly scabrous near apex, 1 -nerved, awnless. 

 linequal. the first 8 mm. long, the second 

 about twice as long : lemma 6 mm. long, 

 smooth except the short-pubescent callus. 2 

 mm. long, the narrowed apex articulated 

 with the slender, spirally twisted 18-mm.- 

 long neck of the awns ; awns equal, spread- 

 ing, about 2.5 cm. long. 



Deserts of southern California, Arizona, and 

 northern Mexico. Apr.-^May. Type locality: Colo- 

 rado Desert, California. 



2. Aristida schiedeana Trin. & Riipr. 

 Schiede's Aristida. Fig. 265. 



Aristida schiedeana Trin. & Rupr. Mem. Acad. St. Petersb. VI. 



Sci. Nat. 5': 120. 1842. 

 Aristida orcuttiana Vasey, Bull. Torrey Club 13: 27. 1886. 



Perennial ; culms erect, scaberulous, 30-60 cm. tall ; 

 sheaths scaberulous, villous at the throat; blades in- 

 volute in drying, the persistent basal ones flat and 

 flexuous, 10-20 cm. long, .5-2 nun. wide ; panicle 

 somewhat open, 10-30 cm. long, the lower branches 

 slender, ascending or spreading, 4-7 cm. long; glumes 

 somewhat unequal, acuminate or short-awned, the 

 first longer, about 1 cm. long; neck of fruit twisted, 

 5-8 mm. long, the central awn spreading. 7-10 mm. 

 long, the lateral awns minute or obsolete ; fruit, in- 

 cluding neck, 15-18 mm. long. 



Deserts and rocks, San Diego (Orcutt) and Arizona to 

 southern Mexico. September. Type locality: Jalapa; of A. orcut- 

 tiana. Lower California. 



3. Aristida divaricata Humb. & Bonpl. 

 Divaricate Aristida. Fig. 266. 



Aristida diiaricata Humb. & Bonpl. in Willd. Enum. 

 PL 99. 1S09. 



Aristida palmcri Vasey, Bull. Torrey Club 10: 42. 

 1883. \ 



Aristida luimboldtiana minor Vasey, Contr. U. S. Nat. 

 Herb. 3: 47. 1892. 



Perennial ; culms cespitose, erect, 30-60 cm. 

 tall; blades involute, as much as 15 cm. long; 

 panicle usually more than half the length of 

 the entire plant; branches distant, mostly in 

 pairs, divaricately spreading, spikelel-bearing 

 toward the ends ; glumes nearly equal, 10-12 

 mm. long, 1-nerved, short-awned, thv-^ first 

 scabrous on the keel ; lemma about 10 mm. 

 long, scabrous toward the straight or twisted 

 neck ; awns about equal. 12-20 mm. long, some- 

 what spreading. 



Deserts and rocky hills, Bakersfield and southward, 

 east to Texas, south to Oaxaca. May-Aug. Type 

 locality: Mexico. 



