MANUAL OF THE GRASSES OF THE UNITED STATES 



721 



Figure 1097. — Setaria macrosperma, X 1. (Curtiss 3617, Fla.) 



California; introduced from Europe; 

 tropical America at medium altitudes. 



Setaria verticillata var. am- 

 bigua (Guss.) Pari. Differing from S. 

 verticillata in the scabrous but not 

 pilose axis of the panicle and the an- 

 trorsely scabrous bristles, mostly 2 to 

 3 times as long as the spikelets, at 

 maturity spreading and more or less 

 implicate. O — Sparingly intro- 

 duced in the United States, ballast, 

 and waste places, Albany, N. Y., 

 Philadelphia, District of Columbia, 

 and Mobile, Ala.; Europe. 



Setaria carnei Hitchc. Resembling 

 S. verticillata (L.) Beauv., but having 

 looser panicles and larger spikelets, 

 brown at maturity. O — A rapidly 

 spreading weed in vineyards, Fresno 

 County, Calif. ; introduced from West- 

 ern Australia. 



4. Setaria macrosperma (Scribn. 

 and Merr.) Schum. (Fig. 1097.) Per- 

 ennial, often in large tufts, 1 to 1.5 m. 

 tall; sheaths keeled; blades elongate, 

 1 to 2 cm. wide, scabrous on upper 

 surface; panicle 15 to 30 cm. long, 2 

 to 4 cm. wide, tapering to both ends, 



rather loose, the secondary panicles 

 smaller, compact, the branches of the 

 terminal panicle as much as 2 cm. 

 long, about equally distributed; bris- 

 tles single below each spikelet, 1.5 to 

 3 cm. long; spikelets 3 mm. long. 91 

 — Open ground, mostly on coral rock 

 or coral sand, Florida; Bahamas. 



5. Setaria villosissima (Scribn. and 

 Merr.) Schum. (Fig. 1098.) Perennial, 

 as much as 1 m. tall; blades flat, vil- 

 lous or scabrous only, 15 to 30 cm. 

 long, 5 to 10 mm. wide; panicle rather 

 loose, more or less interrupted, taper- 

 ing above, as much as 27 cm. long, 

 the branches ascending, the axis vil- 

 lous; bristles 1.5 to 2.5 cm. long; 

 spikelets about 3 mm. long, the sec- 

 ond glume slightly shorter; fruit finely 

 rugose. % — Open or wooded 

 rocky places, Texas and Arizona (lo- 

 cality unknown). Differing from S. 

 macrosperma in the villous blades and 

 looser panicles. 



6. Setaria macrostachya H. B. K. 

 Plains bristlegrass. (Fig. 1099.) 

 Perennial, densely tufted, usually 

 pale or glaucous, 40 to 120 cm. tall; 



