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



Sterile floret neuter. 



Sheaths smooth; awns variable, but the panicle not a dense mass of long- 

 awned spikelets. 

 Panicles erect and rather stiff (heavy panicles somewhat nodding) ; 



spikelets conspicuously hispid 2. E. crusgalli. 



Panicles soft and nodding; spikelets inconspicuously hispid. 



3. E. CRUS-PAVONIS. 



Sheaths, at least the lower, hispid or scabrous; panicle dense, the spikelets 

 long-awned 5. E. walteri. 



1. Echinochloa colonum (L.) Link. Jungle-rice. (Fig. 1551.) 

 Culms prostrate to erect, 20 to 40 cm long; blades rather lax, 3 to 

 6 mm wide, occasionally transversely zoned with purple; panicle 5 

 to 15 cm long; racemes several, 1 to 2 cm long, appressed or as- 



Figure 1554.— Echinochloa crusgalli var. mitis, X 1. 

 (Pammel and Cratty 791, Iowa.) 



Figure 1555.— Echinochloa crusgalli var. 

 zelayensis, X 1. (Mearns 744, Mex.) 



cending, single or occasionally two approximate, the lower usually 

 distant as much as 1 cm; spikelets about 3 mm long, crowded, nearly 

 sessile; second glume and sterile lemma short-pointed, rather soft, 

 faintly nerved, the nerves weakly hispid-scabrous, o — Ditches 

 and moist places, Virginia to Missouri, south to Florida, Texas, and 

 southeastern California; ballast, Camden, N.J., Philadelphia, Pa., and 

 Portland, Oreg. (fig. 1552); tropical regions of both hemispheres; 

 introduced in America. 



2. Echinochloa crusgalli (L.) Beauv. Barnyard grass. (Fig. 

 1553.) Culms erect to decumbent, stout, as much as 1 m or even 

 1.5 m tall, often branching at base; sheaths glabrous; blades elon- 

 gate, 5 to 15 mm wide; panicle erect or nodding, purple tinged, 10 to 

 20 cm long; racemes spreading, ascending or appressed, the lower 

 somewhat distant, as much as 10 cm long, sometimes branched, the 



