No. 19. 

 MUHLENBERGIA CALAMAGROSTIDEA Kth. Gram. i. 63. 



Plant annual, loosely tufted, often purplish throughout. 



Culms geniculate below, erect, branching, slender, striate, nearly smooth, 1 to 3 

 feet high. 



Leaves of culm 3 to 5; sheaths close, slightly hispidulous, shorter than the inter- 

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

 branaceous, lacerate or cleft nearly to the base into two or more linear divisions 1£ 

 lines long. 



Inflorescence a rather loose, narrow, erect or flexuous, interrupted panicle 5 to 8 

 inches long; branches alternate, ascending, U inches long or less, slightly exceeding 

 the intervals, racemose and spikelet-bearing to the base, 



Spikelets nearly sessile or on short hispid pedicels, 1-flowered, 1^ to 1-J lines long; 

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

 bidentate and mucronate, membranaceous, hispid on the keel, 1-nerved; first glume ± to 

 1 line long; second glume :[ line longer; floret deciduous, spindle-shaped, acute, 1-|- to 

 1£ lines long; floral glume ovate, bidentate, membranaceous, usually dotted with pur- 

 ple, minutely roughened, finely pubescent at the base, 3-nerved, the lateral nerves 

 marginal, the middle nerves obscure, excurrent in a slender flexuous awn G to 10 lines 

 long; palet lance-ovate, acute, purple-dotted like the glume, finely pubescent at the 

 base, 2-nervcd, 1 line long; grain nearly terete, tapering to the apex, reddish- brown, § 

 line long. 



Plate XIX; a, spikelet enlarged about 10 times ; b, empty glumes ; c, floral glume; 

 rt, palet. 



Chiefly Mexican, but extending into Arizona and southern California. 



