Xo. 21. 

 MUHLENBERGIA DEBILIS Trin. Agrost. ii. 40. 



Plant spreading", bushy-branched, perennial, usually purple-tinged or dark purple 

 throughout. 



Culms weak, ascending, geniculate and profusely branching below, somewhat 

 thickened at the base aud lower nodes, striate, often angular, smooth, 10 to 15 inches 

 high. 



Leaves of lower nodes usually reduced to scarious sheaths, often several in knotted 

 fascicles at the nodes of much branched specimens. Leaves of culm 1 to 6 ; sheaths 

 slightly scabrid, mostly shorter than the internodes; blades flat, hispid on both sides, 

 1 to 2 inches long; ligule membranaceous, lacerate, 1 line long. 



Inflorescence an erect panicle 2 to 5 inches long, often included at base; branches 

 single or in pairs and unequal, angular, spreading, slightly exceediug their intervals, 

 the lower an inch long, spikelet-beanng to the base. 



Spikelets pedicellate, L-flowered, spindle-shaped, 1£ lines long; empty glumes per- 

 sistent, broadly elliptical, obtuse, thin-membranaceous, smooth, 1-uerved, nearly 

 equal, £ line long or less; floret narrowly spindle-shaped, early deciduous, 1£ lines 

 long; floral glume lanceolate, bidentate at apex, puberulent, finely pubescent on the 

 nerves below, thin, 3-nerved, lateral nerves marginal above, midnerve excurrent in a 

 slender, minutely scabrid awn 1 to 7 lines long; palet lanceolate, nearly acute, cleft, 

 minutely pubesent on the two nerves, 1 to li lines long; stamens 3, included; stig- 

 mas 2, repeatedly branched ; grain narrowly conical, translucent, reddish-amber-color, 

 1 line long. 



Plate XXI; a, spike! et enlarged 25 times; i, empty glumes; c, palet. 



Southern California to western Texas. 



