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



2. Setaria geniculate (Lam.) 

 Beauv. Knotroot bristlegrass. 

 (Fig. 1095.) Resembling S. lutescens 

 but perennial, producing short knotty 

 branching rhizomes as much as 4 cm. 

 long; base of plant slender, wiry; 

 blades mainly straight (not twisted 

 as in S. lutescens); bristles yellow or 

 purple, 1 to 3 times or even 6 times 

 as long as the spikelet; spikelets 2 to 

 2.5 or even 3 mm. long. % — Open 

 ground, pastures, cultivated soil, salt 

 marshes, and moist ground along the 

 coast, Massachusetts to Florida and 

 Texas, in the interior north to West 

 Virginia, Illinois, and Kansas, west to 

 California ; tropical America to Argen- 

 tina and Chile. 



Setaria nigrirostris (Nees) Dur. and 

 Schinz. Perennial; resembling S. lu- 

 tescens, but the dense spikelike ra- 

 cemes purple or dark brown. Ql — 

 Ballast, near Portland, Oreg.; South 

 Africa. 



Setaria sphacelata (Schum.) Stapf and 

 C. E. Hubb. Tufted perennial, glabrous or 

 nearly so, often with stout rhizomes; culms 

 0.5 to 1.5 m. tall, flattened; blades flat, 

 rather lax, 4 to 10 mm. wide; panicle dense, 

 cylindric, 8 to 15 cm. long, usually orange to 

 purple, bristles mostly 5 or more, 3 to 6 mm. 

 long; spikelets 2.5 to 3 mm. long; fruit finely 

 rugose. 21 — Cultivated in experiment 

 stations and escaped along irrigation ditches, 

 Stanislaus and Kern Counties, Calif. Intro- 

 duced from Africa. 



3. Setaria verticillata (L.) Beauv. 

 Bur bristlegrass. (Fig. 1096.) An- 

 nual, often much branched at base 

 and geniculate-spreading, as much as 

 1 m. long; blades flat, rather thin, 

 scabrous and often more or less pilose, 

 10 to 20 cm. long, 5 to 10 mm. wide; 

 panicle erect but not stiff, cylindric or 

 somewhat tapering upward, more or 

 less lobed or interrupted, especially 

 toward base, 5 to 15 cm. long, 7 to 15 

 mm. wide; bristles single below each 

 spikelet, 1 to 3 times as long as the 

 spikelet, retrorsely scabrous; spike- 

 lets 2 mm. long; fruit finely rugose. 

 O — Cultivated soil and waste 

 places, Massachusetts to North Da- 

 kota, south to Alabama, Louisiana, 



Fiqvue 1096.— Setaria verticillata, XI. (Steele, D. C.) and MisSOUH, Occasional West to 





Figure 1095. — Setaria geniculata, X 1. (Chase 2981, 

 Md.) 



