No. 30. 

 SCLEROPOGON KARWINSKIANUS Benth. (Lesourdia Fonrn.) 



Plant perennial, f .'om horizontal rootstock, culms of the season often rising 

 from branches thickly covered with pubescent scales which are the bases of the 

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



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



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

 long; of culm 2 or 3; sheaths usually much shorter than internodes, close, smooth; 

 blade flat or folded, hispid on the back of the midnerve toward the rigid point, 1 

 line wide, 1 to 2 inches long; ligule a dense row of minute stiff bristles, iline long. 



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

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

 bract on the rachis. Spikelets 15- to 30-flowered, 2 to 3 lines wide, \ to \\ inches 

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

 rowly lanceolate', acute, carinate, scarious, 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-g- to '0>\ lines long; palet oblong, flat, with margins 

 infolded, scabrous on the two nerves. 



Female flowers 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; palet 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; 2, pistillate plant; a, staminate flower; b, 

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

 late flower spread out, dorsal view. 



Western Texas and Arizona to Mexico. 



