MANUAL OF THE GEASSES OF THE UNITED STATES 207 



arcuate keels strongly wing-margined ; caryopsis concavo-convex, oval, 

 black, the base of the styles persistent as a 2-toothed crown. Slender 

 perennial with elongate blades and somewhat open panicles. Type 

 species, Vaseyochloa multinervosa. Named from Vasey and Greek, 

 chloa, grass. 



1. Vaseyochloa multinervosa (Vasey) Hitchc. (Fig. 402.) Culms 

 erect, loosely tufted, 40 to 100 cm tall, with slender rhizomes; sheaths 

 scaberulpus, pilose at the throat; blades flat to loosely involute, 1 to 

 4 mm wide; panicle narrow, loose, 5 to 20 cm long, the branches few, 

 at first appressed, later spreading, the lower as much as 8 cm long, 

 bearing a few spikelets from about the middle; spikelets 12 to 18 mm 

 long, 6- to 12-flowered, purple tinged; glumes 

 acute, the first narrow, 4 mm long, the second 

 broad, 5 mm long; lemmas narrowed to an 

 obtuse point, about 6 mm long, the nerves 

 becoming rather obscure toward maturity; 

 grain 2.5 to 3 mm long, 1.5 to 2 mm wide, 

 eeply concave on the ventral side. 91 



(Melica multinervosa Vasey; Distichlis multi- FK "* ^.-Distribution of 



TV NOT -i Schizachne purpurascens. 



nervosa riper.) Sandy open woods or open 



ground, southeastern Texas; rare. The rhizomes appear to break off 



readily, most herbarium specimens being without them. 



31. TRIODIA R. Br. 

 (Tridens Roem. and Schult.) 



Spikelets several-flowered, the rachilla disarticulating above the 

 glumes and between the florets; glumes membranaceous, often thin, 

 nearly equal in length, the first sometimes narrower, 1 -nerved, the 

 second rarely 3- to 5-nerved, acute to acuminate; lemmas broad, 

 rounded on the back the apex from minutely emarginate or toothed 

 to deeply and obtusely 2-lobed, 3-nerved, the lateral nerves near the 

 margin, the midnerve usually excurrent between the lobes as a 

 minute point or as a short awn, the lateral nerves often excurrent as 

 minute points, all the nerves pubescent below (subglabrous in one 

 species), the lateral ones sometimes conspicuously so throughout; 

 palea broad, the two nerves near the margin, sometimes villous; 

 grain concavo-convex. Erect, tufted perennials, rarely rhizomatous 

 or stoloniferous, the blades usually flat, the inflorescence an open to 

 contracted or capitate panicle. Type species, Triodia pungens R. 

 Br. Name from Greek tri, thrice, and odous, tooth, referring to the 

 3-toothed lemma. 



In general the species of Triodia are of little importance economi- 

 cally, T. grandiflora, T. elongata, and T. pilosa being the most useful on 

 the range. Triodia pulchella is often abundant, but is not relished by 

 stock, the little dry plants seldom being eaten. 



la. Panicle capitate, exceeded by fascicles of leaves; low stoloniferous plants. 



1. T. PULCHELLA. 



Ib. Panicle exserted, open or spikelike; plants not stoloniferous. 

 2a. Panicle open, or loose, not dense or spikelike. 



Pedicels of the lateral spikelets less than ] mm long 7. T. LANGLOISII. 



Pedicels all slender, more than 1 mm long (some short in T. buckleyana) , 



55974 35 14 



