MANUAL OF THE GRASSES OF THE UNITED STATES 



465 



4. Aristida glabrata (Vasey) 



Hitchc. (Fig. 675.) Perennial; culms 

 erect, branched, glabrous, 20 to 40 

 cm. tall; blades mostly involute, those 

 of the culm 1 to 3 cm. long; panicle 

 narrow, 3 to 6 cm. long; first glume 

 5 to 6 mm., the second 10 to 12 mm. 

 long; lemma 5 to 7 mm. long, the 

 twisted column 6 to 14 mm. long; 

 awns about equal, divergent, 2 to 3 

 cm. long. % — Open dry ground, 

 southern Arizona to Baja California. 



Section 2. StreptXchne (R. Br.) Domin 

 (Sect. Uniseta Hitchc.) 



Lateral awns minute (less than 1 mm. 

 long) or wanting (see also A. 

 dichotoma and A. ramosissima of 

 Section Chaetaria); lemma not 

 articulate with the column of 

 the awn. 



5. Aristida ternipes Cav. Spider 

 grass. (Fig. 676.) Perennial; culms 



Figure 674. — Aristida californica, X 1. 

 3524, Ariz.) 



(Kearney 



Figure 675.— Aristida glabrata, X 1. (Griffiths 7312, 

 Ariz.) 



erect, 50 to 100 cm. tall; blades flat, 

 involute toward the end and tapering 

 into a fine point, as much as 40 cm. 

 long, 2 to 3 mm. wide; panicle open, 

 one-third to half the entire height of 

 the plant, the branches few, distant, 

 spreading, scabrous, mostly naked at 

 base; spikelets appressed at the ends 

 of the branches; glumes about equal, 

 8 to 10 mm. long; lemma glabrous, 

 often strongly scabrous on the keel, 

 gradually narrowed into a laterally 

 compressed scabrous falcate beak, 

 1-nerved on each side, this extending 

 into a single straight or divergent sca- 

 brous nearly terete awn, the obsolete 



