44() 



POACE.K 



smaller, secoiul not iis hnv^ us tlio spikelet; llonil glume obtuse, 3- 

 ncrved; i)iileii "i-nerveil. Loclicules long, obtuse. Pistilliito flowers 

 iirniiiged iu ti one-sided spike. First empty glume short, obtuse, 

 pilose, second coriuoeous, involute, tipped by 3 long iiwns; floral 

 glume large, compressed, 'i-lobetl, witii a sterile rudiment above 

 bearing 2-3 awns; palea shorter than its glume, obtuse, 2-keeled, 

 enclosing the comjjressed mucronate and subcordate grain; pericarp 

 loose. Lodicules lanceolate. 



b \iliii!li4^ c 



Fig. Sl.—Opma stolonifera. Spikelets. (Scribner.) 



A low creeping grass with short rigid flat or conduplicate leaf- 



l)lades. 



One species known, and that is found in ^lexico. 



1. 0. stolonifera Presl, 1. c. Casiostega anomola Rupr. Bull. 



