Cenchrus 



Andropogoneae 



177 



' ~~ 50 

 Map 330 



Cenchrus pauciflorus Benth. 



Andropoqon scoparius Michx. 



4. Setaria verticillata (L.) Beauv. (Chaetochloa verticillata (L.) 

 Scribn.) Bur Bristlegrass. Map 329. This species has been reported 

 from 7 counties. It is found sparingly (in waste places) probably through- 

 out the state. I have known it in Wells County for 10 years. I first found 

 it in a vacant lot in Bluffton and 10 years later I found it along the road- 

 side outside of the city. Doubtless wherever it gets a start it will gradu- 

 ally spread. 



Nat. of Eu.; Mass. to N. Dak., southw. to Ala., and Mo.; occasionally 

 westw. to Calif. 



137-174. CENCHRUS L. 



[Chase. The North American species of Cenchrus. Contr. U. S. Nation. 

 Herb. 22: 45:77. 1920.] 



1. Cenchrus pauciflorus Benth. (Cenchrus carolinianus of Gray, Man., 

 ed. 7 in part and Cenchrus tribuloides of Britton and Brown, Illus. 

 Flora, ed. 2, not L.) Field Sandbur. Map 330. This sandbur prefers dry, 

 sandy to very sandy soil and is found throughout the state where its 

 habitat occurs. It is local where its habitat is absent and is frequent to 

 common in the northern part of the state in the sandy areas, where it is a 

 very obnoxious weed. It is found in cultivated grounds and waste places, 

 in sandy railroad ballast, and along roadsides. 



Maine to Oreg., southw. to Fla., Tex., and Calif. ; Mexican Plateau, coastal 

 region of tropical America, and s. S. A. 



11. ANDROPOGONEAE Presl Sorghum Tribe 



Spikelets all alike, perfect. 



Rachis of the racemes not articulated; panicle fan-shaped, the panicle axis short. 



Miscanthus, p. 178. 



Rachis articulated; panicle axis elongated 143. Erianthus, p. 178. 



Spikelets of two kinds, one sessile and perfect, the other pedicellate, staminate, empty, 

 or reduced to a mere scale or pedicel. 



