Jones: Flora of Illinois, 22. Gramineae 67 



ulent beneath; spikelets 1.8-2 mm. long; sandy or grav- 

 elly soil in the n. part of 111., not common. June-July .... 

 P. tsugetorum Nash 



62. EcHiNOCHLOA Beauv. 

 1. Sheaths glabrous; spikekts awnless or short-awned. 



2. Spikelets acute or short-awned; panicle green, the branches straight; leaves 

 6-15 mm. wide; fields, roadsides, waste ground, common; nat. from 

 Eurasia. July-Sept. Barnyard Grass E. crusgdli (L.) Beauv. 



2. Spikelets obtuse, awnless; panicle dense, usually dark purple or brown, 

 the branches incurved; leaves 1.5-3 cm. wide; waste places and river 



banks; introd. from s.e. Asia. Japanese Millet. Billion dollar Grass 



E. frumentacea (Roxb.) Link 



1. Sheaths, at least the lower ones, papillose-hirsute; spikelets long-awned, the 



awns 1-5 cm. long, usually purple; wet ground. Aug.-Oct 



E. walteri (Pursh) Heller 



63. Setaria Beauv. 

 {Chaelochloa Scribn.) 



1. Plants perennial with short, branched rhizomes; bristles below each spikelet 

 8-12, yellowish or purplish, upwardly scabrous; waste ground, occasional. 

 [5". imberbis R. fid S.} S. geniculata (Lam.) Beauv. 



1. Plants annual. 



2. Bristles 5-15 at the base of each spikelet, upwardly barbed; a common 

 weed in waste ground and along roads; nat. from Eur. June-Sept. [5'. 



glauca of auth., not (L.) Beauv.} Yellow Foxtail 



S. lutescens (Weigel) F. T. Hubb. 



2. Bristles 1-3 at the base of each spikelet. 

 3. Spikelets about 2 mm. long. 

 4. Bristles 3-6 mm. long, retrorsely barbed; panicle 5-15 cm. long; weed 



in waste ground; nat. from Eur. July-Sept. Bristly Foxtail 



S. vertiallata (L.) Beauv. 



4. Bristles 7-12 mm. long, upwardly barbed; panicle usually less than 

 7 cm. long; a common weed throughout III.; nat. from Eur. June- 

 Sept. Green Foxtail S. yiridis (L.) Beauv. 



3. Spikelets 3 mm. long; bristles upwardly barbed; panicle thick, lobed or 

 interrupted, purplish or yellowish; cult, and sometimes spontaneous; 

 introd. from Eurasia. July-Sept. Italian Millet, or Hun3arian Grass 

 S. italica (L.) Beauv. 



64. Cenchrus L. — Sandbur 



C. longiipinus (Hack.) Fern. Sandy soil, cult, ground, and roadsides. 

 July-Sept. [C. tribidoides sensu auth., non L.; C. carolintanus sensu auth., 

 scarcely Walt.; C. pauciflorus sensu auth., non Benth.} 



65. Andropogon L. 

 1. Racemes usually borne singly on the few to many branches, 3-6 cm. long; 



