No. 19. 

 MUHLENBERGIA CALAM AGROSTIDE A Kth. Gmm. i. 0.1. 



I'Idiit aiiiiiMl, loosely tuftcil, ofteu purplish tlirou}j,iioiit. 



Cidmn fjcniiiilate hclow, erect, braucliiiifr, shmder, striate, nearly smooth, 1 to .'} 

 feel liiiih. 



Leaven of culm 3 to '>; sheaths close, slif;htly hisi)itlul()us, shorter than the inter- 

 nodes; blades Hat or involute, hispidulous, a line wide, 1 to 2 inches long; ligule mem- 

 hranaceous, lacerate or cleft nearly to the base into two or more linear divisions Ih 

 lines long. 



Injiorcncence a ratiier loose, narrow, erect or flexuons, interrupted panicle 5 to S 

 inches long; branches alternate, ascending, li in(;lies long or less, slightly exceeding 

 the intervals, racemose and s])ikelet bearing to thebkse. 



Spikelets nearly sessile or on short hispid i»edicels, 1-flowered, 1^ to I A lines long; 

 empty glumes ))ersisteiit, divergent, lance-ovate, acute, subulate-pointed or minutely 

 bideiitate and mucronate, membranaceous, his])idon the kind, 1-nerved; tirst glume A to 

 1 line long; second glume \ line longer; floret deciduous, sitindle-shaped, acute, 1^ to 

 l.i lines long; lloral glume ovate, bidentate, membranaceous, usually dotted with pur- 

 l)le, minutely roughened, lincly ])ubesceid at the base, .'5-nerved. the lateral nerves 

 marginal, the middle nci-ves obscure, excurrent in a sh^nder tlexuous awu G to 10 lines 

 long; palet lance-ovate, acute, ]iurple-dotted like the glume, liuely pubescent at the 

 base, 2-nerved, 1 line long; grain nearly terete, tai)e.ring to the apex, reddish- brown, § 

 line long. 



I'LATK XIX; a, s]»ikelet enlarged about lOtimes; /<, empty glumes; c, lloral glume; 

 //, palet. 



Chiefly Mexican, but extending into Arizona and southern California. 



