GENERA OF GRASSES OF THE UNITED STATES. 



237 



Annuals or perennials, of wet soil, usually branching, the inflores- 

 cence a dense, usually elongate, spikelike panicle. Species about 



12; in the Tropics of both hemi- 

 spheres, 1 extending into the south- 

 eastern United States. 



Type species: Panicum gibbum Ell. 

 Sacciolepis Nash, in Britton, Man. 80. 

 1901. Only one species is described. 



Sacciolepis striata (L.) Nash 

 (Holcus striatm L., Panicum. gib- 

 bum Ell.) (fig. 144) is a stolonifer- 

 ous marsh grass found from Vir- 

 ginia to Oklahoma and southward. 

 It has no economic value. 



121. OPLISMENUS Beauv. 



Spikelets terete or somewhat lat- 

 erally compressed, subsessile, soli- 

 tary or in pairs, in two rows 

 crowded or approximate on 

 one side of a narrow scabrous 

 or hairy rachis; glumes 

 about equal, emarginate or 

 2-lobed, awned from between 

 the lobes; sterile lemma ex- 

 ceeding the glumes and fruit, 

 notched or entire, mucronate 



FIG. 144. Sacciolepis striata. Plant, X J ; two views of spikelet and fertile floret, 



X 10. 



or short-awned, inclosing a hyaline palea ; fertile lemma elliptic, acute, 

 convex or boat shaped, the firm margins clasping the palea, not inrolled. 



