109 



Fig. 405. Cenchrus incertus M. A. Curt. Bost. Journ. Nat. 

 Hist. 1 : 135. 1837. (C. strictus Chapm. Coult. Bot. Gaz. 3 : 20. 

 1878.) Southern Sand-bur. — A smooth, ascending, and more 

 or less branched perennial ( ?), 4.5 to 9 dm. high, with flat leaves 

 and slender spikes 5 to 8 cm. long. Spikelets inclosed in a bur- 

 like involucre (a) which is naked below, with 6 to 12 stout spines 

 above. — Sandy soil along the coast, Georgia to Florida and west- 

 ward to Texas. June-October. 



