No. 19. 

 SPOROBOLUS TRICHOLEPIS (Torr). ( Vilf 'a tricliolepis Torr.) 



Plant slender, perennial, often purplish in culm and inflorescence, smooth 

 throughout. 



Culms tufted, erect, seldom branching, smooth, slightly compressed, 1 to 2 

 feet tall. 



Leaves of radical shoots with rather loose, scarious sheaths and narrow invo- 

 lute blades 2 to 4 inches long; of culm 2 or 3; sheaths close, nearly equaling or 

 exceeding internodes, blades involute, erect, 2 to 3 inches long; ligule membrana- 

 ceous, truncate, lacerate, decurrent, i line long or less. 



Inflorescence an ovate, pyramidal, erect, or flexuous panicle, 4 to 6 inches long; 

 branches mostly alternate, slightly spreading, 1 to 2 inches long, divided and 

 rather loosely flowered on the upper two-thirds. 



Spikelets on long slender pedicels, lanceolate, 1-flowered, 1^ lines long; first 

 and second glumes nearly equal lanceolate, acute or obtuse, carinate, thin, smooth, 

 1-nerved, 1 to 1-j lines long; floral glume lanceolate, acute, or obtuse, mem- 

 branaceous, pubescent or villous on the 3 nerves, 1^ lines long; palet lanceolate, 

 acute, membranaceous, slightly ciliate above, pubescent on the 2 approximate 

 nerves, or nearly smooth, 1\ lines long. 



Grain narrowly elliptical, compressed, yellow, ^ line long. 



Plate XIX; a, empty glumes; b, floral glume and palet opened to show 

 stamens and pistil. 



Mexico northward to Colorado. 



