MANUAL OF THE GRASSES OF THE UNITED STATES 



431 



11. Stipa pulchra Hitchc. Purple needlegrass. (Fig. 901.) 

 Culms 60 to 100 cm tall; blades long, narrow, flat or involute; ligule 

 about 1 mm long; panicle nodding, about 15 cm long, loose, the 

 branches spreading, slender, some 

 of the lower 2.5 to 5 cm long; 

 glumes narrow, long-acuminate, 

 purplish, 3-nerved, the first about 

 2 cm long, the second 2 to 4 mm 

 shorter; lemma 8 to 10 mm long, 

 fusiform, sparingly pilose, some 

 times only in lines above, minutely 

 papillose-roughened, the callus 

 about 2 mm long, the summit some- 

 times with a smooth neck and a 

 ciliate crown (as in S. leucotricha) ; 

 awn 4 to 6 cm long, short-pubescent 

 to the second bend, the first seg- 

 ment 1.5 to 2 cm long, the second 

 shorter, the third slender, flexuous. 

 % ^ — Open ground, central Cali- 

 fornia to Baja California, mostly 

 in the Coast Ranges. 



12. Stipa pringlei Scribn. Prin- 



GLE NEEDLEGRASS. (Fig. 90 2.) 



Culms, about 1 m tall ; ligule about 



2 mm long; blades 10 to 30 cm long, 



1 to 3 mm wide, flat or those of 



the innovations involute, firm, erect, 



scabrous, panicle nodding, 10 to 15 



cm long, the branches ascending, 



few-flowered, naked below; glumes about 1 cm 

 broad, rather abruptly narrowed into a 

 short point, 7- to 9-nerved; lemma 7 to 

 8 mm long, oblong-elliptic, brown, minutely 

 papillose and brownish pubescent, the callus 

 1 mm long; awn about 3 cm long, ob- 

 scurely twice-geniculate. 01 — R o c k y 

 woods and slopes, Texas, New Mexico, and 

 Arizona to Chihuahua, Mex. 



13. Stipa eminens Cav. (Fig. 903.) 

 Culms slender, rather wiry, 80 to 120 cm 

 tall; ligule 3 to 6 mm long; blades mostly 

 elongate, flat or involute, 1 to 4 mm wide; 

 panicle nodding, open, 10 to 20 cm long, 

 usually densely pilose on the lower node, 

 the branches slender, spreading, often 

 flexuous, usually 3 to 4 or even more at 

 the node; glumes about 1.5 cm long; lem- 

 ma pale, 5 to 7 mm long, pubescent; awn 

 3 to 6 cm long, obscurely twice-geniculate, 



the third segment flexuous. % — Rocky hills, Texas to Arizona 



and central Mexico. 



Figure 901.— Stipa pulchra. Panicle, XM; 

 lemma, X 5. (Chase 5598, Calif.) 



Figure 902.— Stipa 

 pringlti. Floret, 

 X 1; lemma, X 5. 

 (Hitchcock 7691, 

 Mex.) 



Figure 

 Stipa eminens. 

 Floret, X 1; 

 lemma, X 5. 

 (Palmer 523, 

 Mex.) 



55974°— 35 28 



