454 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



axdersoxii (Vasey) Hitchc. Differing 

 only in the more slender culms, the 

 slender involute blades, and in the 

 narrow or reduced panicle. — Same 

 range as the species. 



16. Stipa porteri Rydb. (Fig. 653.) 

 Culms 20 to 35 cm. tall; ligule 2 to 

 3 mm. long; blades 2 to 12 cm. long, 

 involute, subfiliform, sulcate, sca- 

 berulous; panicle mostly 5 to 10 cm. 

 long, open, the branches distant, 

 capillary, flexuous, few-flowered ; 

 glumes 5 to 6 mm. long: lemma about 

 5 mm. long, oblong-elliptic, softly 

 pilose on the lower half, scaberulous 

 above, lobed at summit; awn 12 to 

 15 mm. long, plumose with hairs 1 



Figure 652. — Stipa lep- 

 ida. Floret, X 1; 

 lemma, X 5. (Chase 

 5609, Calif.) 



Figure 653. — Stipa por- 

 teri. Floret, X 1; lem- 

 ma, X 5. (Wolf 1109, 

 Colo.) 



to 100 cm. tall; sheaths smooth, 

 rarely puberulent, sparingly villous 

 at throat; ligule ver} T short; blades 

 10 to 30 cm. long, flat, 2 to 4 mm. 

 wide, pubescent on upper surface 

 near base; panicle rather loose and 

 open, usually 15 to 20 cm. long, 

 sometimes more than 30 cm. long, 

 the branches distant, slender; glumes 

 3-nerved, smooth, acuminate, the 

 first 6 to 10 mm. long, the second 

 about 2 mm. shorter; lemma about 

 6 mm. long, brown, sparingly villous, 

 nearly glabrous toward the hairy- 

 tufted apex; awn indistinctly twice- 

 geniculate, about 2.5 to 4 cm. long, 

 scabrous. % — Dry hills, open 

 woods, and rocky slopes, central 

 California to Baja California, in the 

 Coast Range. Stipa lepida var. 



Figure 654. — Stipa thurberinna. 

 Floret, X 1; lemma, X 5. 

 (Chase 4689, Idaho.) 



Figure 655. — Stipa elmeri. Floret, X 

 1: lemma, X 5. (Hitchcock 3336, 

 Calif.) 



to 2 mm. long, with a single bend 

 one-third from the base, the first 

 segment weakly twisted. % — 

 High mountains of Colorado. 



17. Stipa thurberiana Piper. 



THURBER XEEDLEGRA5S. (Fig. 654.) 



Culms mostly 30 to 60 cm. tall; 

 sheaths scaberulous or the upper gla- 

 brous; ligule hyaline, 3 to 6 mm. 

 long; blades 10 to 25 cm. long, 

 filiform, involute, scabrous to densely 

 soft-pubescent, flexuous; panicle most- 

 \y 8 to 15 cm. long, narrow, the 

 ascending branches few flowered; 

 glumes 11 to 13 mm. long, the acu- 

 minate summit hyaline; lemma 8 to 

 9 mm. long, appressed-pubescent, 

 callus about 1 mm. long; awn 4 to 

 5 cm. long, twice-geniculate, the first 

 and second segments plumose with 



