MANUAL OF THE GRASSES OF THE UNITED STATES 433 



17. Stipa elmeri Piper and Brodie. (Fig. 908.) Culms 60 to 100 

 cm tall, more or less puberulent, especially at the nodes; sheaths 

 pubescent; ligule very short; blades 15 to 30 cm long, 2 to 4 mm wide, 

 flat or becoming involute, pubescent on the upper sur- 

 face, or those of the innovations also on the lower sur- 

 face; panicle narrow, 15 to 35 cm long, rather loose; 

 glumes 12 to 14 mm long, long-acuminate, hyaline 

 except toward base; lemma about 7 mm long, appressed- 

 pubescent, the callus 1 mm long; awn 4 to 5 cm long, dis- 

 tinctly twice-geniculate, the seg- 

 ments nearly equal, the first and 

 second finely plumose. % — 

 Dry hills, sandy plains, and open 

 woods, Washington and Idaho to 

 California and Nevada (fig. 909). 

 18. Stipa latiglumis Swallen. 

 (Fig. 910.) Culms slender, erect, 

 strigose below, 50 to 110 cm tall; 



sheaths, at least the lower, pubescent; blades flat or loose- 

 ly involute, pilose on the upper surface, glabrous beneath ; 

 ligule 1 to 4 mm long; panicle narrow, loosely flowered, 

 15 to 30 cm long, the branches distant, slender, the lower 

 as much as 10 cm long; glumes about equal, firm, rather 

 abruptly acute or acuminate, 3-nerved, tinged with purple, 

 13 to 15 mm long, 1.5 mm wide from keel to margin; lemma densely 

 pubescent, 8 to 9 mm long, the sharp callus 1 mm long; awn twice- 

 geniculate, 3.5 to 4.5 cm long, the first 

 and second segments plumose. 91 

 — Sierras of central California at 

 medium altitudes. 



19. Stipa occidentalis Thurb. 

 Western needlegrass. (Fig. 911.) 

 Culms mostly 25 to 40 cm tall; 



Figure 909.— Distribution of 

 Stipa elmeri. 



Figure 908 — 

 Stipa elmeri. 

 Floret, X 1; 

 lemma, X 5. 

 (Hitchcock 

 3336, Calif.) 



Figure 912— Distribution of Stipa occidentalis. 



sheaths glabrous; ligule about 0.5 mm 

 long; blades 10 to 20 cm long, 1 to 2 

 mm wide, flat or usually involute, gla- 

 brous beneath; panicle 10 to 20 cm 

 long, lax, the few slender branches 

 narrowly ascending; glumes about 12 

 mm long, the attenuate tips hyaline; lemma pale 

 brown, about 7 mm long, rather sparsely appressed- 

 pubescent; awn 3 to 4 cm long, twice-geniculate, 

 the first and second segments plumose, the hairs 

 about 1 mm long. % —Plains, rocky hills, and open woods, 

 Wyommg to Washington and California (fig. 912). 



Figure 910— Sti- 

 pa latiglumis. 

 Floret, X 1; 

 lemma, X 5. 

 (Type.) 



Figure 911.— Stipa 

 occidentalis. Panicle, 

 X Vi\ lemma, X 5. 

 (Hitchcock 11740, 

 Oreg.) 



