No 13. 



CATHESTECUM ERECTUM Vasey & Hackel. 



Plant perennial. 



Roots slender. Rootstock none. 



Stems of two kinds, (1) runners and (2) erect culms. Runners slender, with, 

 internodes few to several inches long, glabrous, arcuate, giving rise to a new plant 

 at each node. Culms densely tufted below, many of them short and leafy, a few 

 elongated, very slender, 6 to 10 inches high, glabrous. 



Leaves of the root numerous; sheath short, \ to 1 inch long, glabrous, long- 

 ciliate at the apex; blade 3 inches or less long, about 4 line wide, scabrous on the 

 margins, otherwise glabrous or rarely with a few long hairs; ligule minute, fim- 

 briate. Leaves of the stems 2 or 3; sheaths about 1 inch long, distant, otherwise 

 like those of the root; blade from 1 inch long to almost wanting. 



Inflorescence racemose; spikelets in a raceme of 4 to 8 clusters; racemes slender- 

 pedunculate, about 1 inch long, single or 2 or 3 together from the uppermost sheath ; 

 rachis very slender, flat, glabrous or slightly scabrous; clusters short-pedicellate, 

 composed of 3 spikelets, middle spikelet short-pedicelled, lateral nearly sessile. 



Glumes 4 to 6; first small, truncate-cuneate, empty, nearly nerveless; second 

 empty, lanceolate, 1-nerved; others subtending flowers, 4-lobed, 3-nerved, more 

 or less scabrous on the back, the nerves extending into a short scabrous awn 

 between the lobes. 



Flowers 3 to 4, hermaphrodite (?); palet lanceolate, 2-nerved, stamens 3, an- 

 thers 1 to li lines long; pistils not detected; sterile prolongation of the rachilla 

 sometimes found at the apex of the spikelets. 



Grain not found. 



Plate XIII; a, cluster of spikelets; b, first glume; c, second glume; cl and e, 

 two flowering glumes; /, palet, from the back; g and h, palets, from the front; 

 i, sterile prolongation of the rachilla; j, stamens and pistils; k, anther and 

 upper portion of filament. 



This grass is found on the arid bluffs of the Rio Grande in Texas, and westward 

 near the Mexican border as far as Sonora. It is too small to be of much economic 

 importance. 



