No. 30. 

 SCLEROPOGON KARWINSKIANUS Benth. {Lesourdia Fourn.) 



Plaid perennial, from horizontal rootstock, culms of the season often rising 

 from liranches thickly covered with imbescent scales which are the bases of the 

 leaf sheaths of jjrevious seasons; new growth, rather glaucous throughout. 



Cidin ascending, slender, terete, smooth, branching below, G to 12 inches tall. 



Ledvcs of sterile culms, and radical, numerous, with flat blades 1 to 2 inches 

 long; of culm 3 or .'5 ; sheaths xisually mucli sliorter than internodes, close, snujotli; 

 blade flat or folded, hispid on the bacdc (^f the midnerve toward the rigid point, 1 

 line wide, 1 to 3 inches long: ligiile a dense row of minute stifl: bristles, ^line long. 



Inflorescence unisexual, flowers on distinct culms. Male flowers forming a short, 

 close panicle of 5 to 8 spikelets on short jjedicels, often subtended by a narrow 

 bract on the rachis. Spikelets 15- to .30-fl()wered, 2 to 3 lines wide, ^ to 1^ inches 

 long, rachilla glabrous, internodes f line long; first and second glumes equal, nar- 

 rowly lanceolate, acute, carinate, scarioiis, smooth, 1-nerved, 2 lines long; floral 

 glumes lance-ovate, acute or often with short awn and 2 or 4 teeth at apex, scari- 

 ous, 3-nerved, smooth, 2^ to 3^ lines long; palet oblong, flat, with margins 

 infolded, scabrous on the two nerves. 



Female floicers forming an irregular narrow panicle of 3 to 7 few-flowered 

 spikelets, each subtended by a narrow bract; first glume narrowly lanceolate, with 

 long, tapering point, smooth, obscurely 5-nerved, 4 to 6 lines long; second glume 

 lanceolate, smooth, 3-nerved, 6 to 8 lines long; internodes of rachilla 1 line long, 

 stipe bristly pubescent; floral glume linear, 4 to 5 lines long, the 3 nerves termi- 

 nating in slender twisted awns, 2 to 5 inches long, with membranaceous expan- 

 sions at the sides between each awn; jjalet lanceolate, acute or somewhat lacerate 

 at the apex, hispid on the 2 nerves above, scarious margins folding closely over the 

 grain, 4 to 5 lines long. 



Grain light amber color, cylindrical, bifid at top, 2 lines long. 



Plate XXX; 1, .staminate plant; 3, pistillate plant; a, stamiuate flower; h, 

 pistillate spikelets partly dissected and the awns cut off; c, floral glume of pistil- 

 late flower sjjread out, dorsal view. 



Western Texas and Arizona to Mexico. 



