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



11. Setaria magna Griseb. Giant bristlegrass. 

 Annual, robust, erect; culms spar- 

 ingly branching, as much as 4 m 

 tall and 2 cm thick at base; blades 

 flat, scabrous, as much as 50 cm 

 long and 3.5 cm wide; panicles 

 densely flowered, nodding, often 

 interrupted at base, tapering at 

 each end, as much as 50 cm long and 

 3 cm thick, those of the branches 

 much smaller; bristles 1 to 2 cm 

 long; spikelets about 2 mm long; 



1 



(Fig. 1577.) 



Figure 1571.— Distribution of 

 Setaria macrostachya. 



fruit smooth or nearly 

 so, brown and shining 

 at maturity. o — 

 Marshes and wet places 

 along the coast, New 

 Jersey to Florida and 

 Texas; West Indies (fig. 

 1578). 



V 



Figure 1572. 



-Setaria scheelei, X 1. (Bush 1244, Tex.) 



12. Setaria viridis (L.) Beauv. 

 Green bristlegrass. (Fig.1579.) 

 Annual, branching at base, some- 

 times geniculate-spreading, 20 to 

 40 cm tall (or even 1 m) ; blades 



Figure 1574.— Distribution of 

 Setaria corrugata. 



flat, usually less than 15 cm long 

 and 1 cm wide; panicle erect 

 or somewhat nodding, densely 

 flowered, green or purple, cylin- 

 dric but tapering a little at the summit, 

 usually less than 7 cm long; bristles 1 to 3 

 below each spikelet, mostly 3 to 4 times their 

 length; spikelets 2 to 2.5 mm long; fruit 

 very finely rugose, o — A weed in cul- 

 tivated soil and waste places, common 

 throughout the cooler parts of the United 

 States, Newfoundland to British Columbia, 

 south to Florida and California, infrequent in the Southern States 

 and in the mountains; introduced from Europe. 



Figure 1573.— Setaria corrugata, X 1. 

 (Pollard and Collins 253, Fla.) 



