450 



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



branches slender, distant, spreading 

 or drooping, naked below; glumes 8 

 to 9 mm. long; lemma about 5 mm. 

 long, subfusiform, brown at matu- 

 rity; awn 2.5 to 3 cm. long. 21 — 

 Bottom lands and wooded slopes, 

 Saskatchewan to South Dakota, Colo- 

 rado, Idaho, and British Columbia. 



Figure 644. — Stipa avenacioides. Floret, X 1; lemma, 

 X 5. (Curtiss 5834, Fla.) 



7. Stipa avenacioides Nash. (Fig. 

 644.) Culms about 1 m. tall; ligule 2 

 to 3 mm. long; blades elongate, in- 

 volute, subfiliform; panicle 10 to 25 

 cm. long, open, the branches slender, 

 spreading, naked below; glumes about 

 2 cm. long; lemma brown, linear, 1.5 

 to 2 cm. long including the callus 7 

 mm. long, the body glabrous, mi- 

 nutely papillose at the slightly con- 

 tracted summit, slightly hispidulous 

 on the crown; awn 8 to 11 cm. long, 

 scabrous, twice geniculate. % — 

 Dry pine woods, peninsular Florida. 



8. Stipa avenacea L. Blackseed 

 needlegrass. (Fig. 645.) Culms 60 

 to 100 cm. tall; ligule about 3 mm. 

 long; blades 20 to 30 cm. long, 1 mm. 

 wide, flat or involute; panicle 10 to 

 15 cm. long, open, the slender 

 branches 2 to 4 cm. long, bearing 1 

 or 2 spikelets; glumes 1.5 cm. long; 

 lemma dark brown, 9 to 10 mm. long, 

 the callus 2 mm. long, the body gla- 

 brous, papillose-roughened toward 

 the summit, awn scabrous, 4.5 to 6 

 cm. long, twice-geniculate. % — 

 Dry or rocky open woods, Massachu- 

 setts to Michigan south to Florida 

 and Texas, mostly on the Coastal 

 Plain. 



Figure 645. — Stipa avenacea. 

 Floret, X 1; lemma, X 5. 

 (Kneucker, Gram. 564, Md.) 



9. Stipa spartea Trin. Porcupine 

 grass. (Fig. 646.) Culms about 1 m. 

 tall; ligule rather firm, 4 to 5 mm. 

 long; blades 20 to 30 cm. long, 3 to 5 

 mm. wide, flat, involute in drying; 

 panicle 15 to 20 cm. long, narrow, 

 nodding, the few slender branches 

 bearing 1 or 2 spikelets; glumes 3 to 

 4 cm. long; lemma subcylindric, 

 brown, 1.6 to 2.5 cm. long, the callus 

 about 7 mm. long, the body pubes- 

 cent below, glabrous above except for 

 a line of pubescence on one side, the 

 crown erect-ciliate; awn stout, 12 to 

 20 cm. long, twice geniculate. 01 

 — Prairies, Ontario to British Colum- 

 bia; Pennsylvania to Montana, Mis- 

 souri, and New Mexico. Stipa spar- 

 tea var. curtiseta Hitchc. Glumes 



