GENERA OF GRASSES OF THE UNITED STATES. 73 



Our species, Anthochloa colwatw (Davy) Scribn. (fig. 33), is 

 known only from the type collection, from Colusa County, Calif. It 

 is an annual, with broad flat leaves with no distinction between 

 sheath and blade, and dense cylindric spikes, the upper part of the 

 axis bearing, instead of spikelets, lanceolate-linear empty bracts. 



FIG. 33. Anthochloa colusana. Plant X ; spikelet and floret, X 5. 

 26. TRIODIA R. Br. 



Spikelets several-flowered, the rachilla disarticulating above the 

 glumes and between the florets; glumes membranaceous, often thin, 

 nearly equal in length, the first sometimes narrower, 1 -nerved or the 

 second rarely 3 to 5 nerved, acute or acuminate; lemmas broad, 

 rounded on the back, the apex from minutely emarginate or toothed 

 to deeply and obtusely lobed, 3-nerved ; the lateral nerves near the 

 margins, the midnerve excurrent between the lobes as a minute point 

 or as a short awn, the lateral nerves often excurrent as minute points, 

 all the nerves pubescent below (subglabrous in one species), the lat- 

 eral ones sometimes conspicuously so throughout; palea broad, the 

 two nerves near the margin, sometimes villous. 



Erect, tufted perennials, rarely rhizomatous or stoloniferous, the 

 blades usually flat, the inflorescence an open or contracted panicle, 

 or a cluster of few-flowered spikes interspersed with leaves. Species 

 about 25, mostly in America ; 15 species in the United States. 



