No. 10. 



ORYZOPSIS MEMBRANACEA (Pursli.). (Stipa membranacea Pursli.) 

 Eriocoma cuspidata Nutt.) 



Plant perennial, closely tufted, thickened at base. 



Culms slender, nearly erect, not branching, geniculate, solid, terete, smooth, 

 12 to 18 inches tall. 



Leaves; radical, numerous, the scarious sheaths clustered thick about the base 

 of the culms; blades involute, smooth, 6 to 10 inches long; of the culms 3; lower 

 sheaths shorter than internodes, smooth and close, upper sheath longer and loose; 

 blades like those of radical leaves; ligule membranaceous, ovate, acute, or lace- 

 rate, 1 line long, prominently decurrent. 



Inflorescence a very loose, erect or flexuous panicle 4 to 6 inches long, included 

 at the base, usually with 2 or 3 nearly equal axes; branches mostly in pairs, dis- 

 tant, horizontal, divided in pairs beyond the middle, bearing solitary spikelets ou 

 long flexuous pedicels. 



Spikelets 1 -flowered, 3 lines long; first and second glumes equal, inflated and 

 widened below, narrowed above to a long sharp point, scarious except the 5 rather 

 obscure nerves, minutely pubescent throughout, 3 lines long; floral glume ovoid 

 or oblong, hard, dark-brown, profusely clothed with long white hairs, li lines 

 long, obscurely nerved, terminating in an awn 2 lines long, which falls at maturity; 

 palet conical, smooth, hard, brown, obscurely nerved, 1-g- lines long. 



Grain oval, light-yellow, f line long. 



Plate X; a, spikelet; b, empty glumes; c, floral glume, with hairs and awn; 

 d, same after hairs and awn have fallen; e, palet. In the floral glume, c, the awn 

 should be represented more to one side. 



Texas to California, northward to British Columbia, usually in sandy or grav- 

 elly soil. A valuable grass. The large seeds are nutritious, and cattle fatten 

 where the grass is abundant. 



