GENERA OF GRASSES OF THE UNITED STATES. 



135 



apex, bearing from between the teeth a slender bent awn, twisted at 

 base ; palea a little shorter than the lemma. 



A slender annual with flat blades and narrow panicles. Species 



one, Florida to Texas. 



Type species : Greenia arkansana 

 Nutt. 



Greenia Nutt., Trans. Amer. Phil. Soc. 

 5: 142, 1837, not Greenea Wight and 

 Arn., 1834. Type O. arkansana, the only 

 species described. 



Sclerachne Torr. ; Trin., Mem. Acad. 

 St. PStersb. VI. Sci. Nat. 4 1 : 273, 1841, 

 not Sclerachne R. Br. and Benn., 1838. 

 Two species are described, S. arkansana 

 Torr. and 8. pilosa Trin. The first, 

 based on Greenia arkansana Nutt., is 

 the type. 



Thurberia Benth., Journ. Linn. Soc. 

 Bot. 19: 58, 1881, not Thurberia A. 

 Gray, 1854. Type Greenia arkansana 

 Nutt., the name Thurberia being substi- 

 tuted for Greenia. 



Limnodea L. H. Dewey, Contr. U. S. 

 Nat. Herb. 2: 518. 1894. Only one spe- 

 cies described. 



Limnodea arkansana 

 (Nutt.) L. H. Dewey 

 (fig. 73), has probably 

 no agricultural value. 

 A form with pilose 



t 



FIG. 73. Limnodea arkansana. Plant, X I ; spikelet and floret, X 5. 



