460 



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



capillary, scaberulous, loosely twisted 

 for 1 or 2 cm., flexuous beyond. 91 

 -Rocky slopes, Texas, Colorado to 

 Arizona and California (Funeral 

 Mountains) . 



Figure 670. — Stipa arida. Floret, X 1 ; lemma, X 5. 

 (Jones 5377, Utah.) 



34. Stipa tenuissima Trin. (Fig. 

 671.) Culms in large tufts, slender, 

 wiry, 30 to 70 cm. tall; ligule 2 mm. 

 long; blades 15 to 30 cm. long, some- 

 times longer, filiform, wiry, closely 

 involute; panicle 10 to 30 cm. long, 

 narrow, soft, nodding; glumes about 

 1 cm. long; lemma 2 to 3 mm. long, 

 oblong-elliptic, glabrous, minutely 

 papillose-roughened, the short callus 

 densely pilose; awn about 5 cm. long, 

 capillary, flexuous, obscurely genic- 

 ulate about the middle. % — Dry 

 open ground, rocky slopes, and open 

 dry woods, Texas and New Mexico 

 to central Mexico; Argentina. 



Stipa neesiana Trin. and Rupr. 

 Related to S. leucotricha but with 

 shorter lemma with thickened erose 

 crown. 01 — Ballast, Mobile, Ala.; 

 South America. 



Stipa brachychaeta Godr. Blades 

 firm, flat, or loosely involute; panicle 

 narrow, open, the few spikelets on 

 slender pedicels; glumes 8 mm. long; 

 lemma 5 mm. long, brown, pubescent 

 in lines; awn 12 mm. long. % — 

 Ballast near Portland, Oreg. ; Argen- 

 tina. 



Stipa elegantissima Labill. Tufted per- 

 ennial; foliage scant; panicle commonly half 

 the height of the plant, the filiform spread- 

 ing branches conspicuously feathery; spike- 

 lets purple, long-awned. 21 — Sometimes 

 cultivated for ornament; Australia. 



Stipa pennata L. Tufted perennial ; blades 

 elongate, involute; panicle few-flowered, the 

 large spikelets with awns 25 to 35 cm. long, 

 conspicuously feathery above the bend. % 

 — Sometimes cultivated for ornament; Eu- 

 rope. 



Stipa tenacissima L. Esparto. Tufted 

 perennial with tough branching base; blades 

 elongate, involute, tomentose at base and 

 with erect auricles 3 to 10 mm. long; panicle 

 narrow, dense; awns 4 to 6 cm. long, feathery 

 below the bend. % — Sometimes culti- 

 vated for ornament; Spain and Algeria, 

 where it is gathered for making paper and 

 cordage; also in Portugal and Morocco. 



Stipa splendens Trin. Robust perennial, 

 1.2 to 2 m. tall; foliage scabrous; panicle 30 

 to 50 cm. long, many-flowered, but loose; 

 spikelets 5 to 6 mm. long; lemma as long as 

 the glumes, silky; awn weakly geniculate, 

 10 to 15 mm. long. % — Introduced from 

 Siberia under the name "chee grass," spar- 

 ingly cultivated. Seed of Calamagrostis epi- 

 geios was mixed with the first introduction 

 and "chee grass" was erroneously applied to 

 that, which thrived more vigorously than 

 the Stipa. 



92. ARISTIDA L. Three-awn 



Spikelets 1-flowered, the rachilla disarticulating obliquely above the glumes; 

 glumes equal or unequal, narrow, acute, acuminate, or awn-tipped; lemma 

 indurate, narrow, terete, convolute, with a hard, sharp-pointed, usually 

 minutely bearded callus, terminating above in a usually trifid awn (the lateral 

 divisions reduced or obsolete in Section Streptachne) , the base sometimes un- 

 divided, forming a column. Annual or perennial, mostly slender tufted grasses, 

 with narrow, frequently convolute blades and narrow or sometimes open 

 panicles. Type species, Aristida adscensionis L. Name from Latin arista, awn. 



The species are of distinctly minor importance for forage except in the 

 Southwest, where several, such as A. longiseta, are eaten by stock before the 



