No. 40. 



TRIODIA TRINERVIGLUM1S (Munro) (Tricuspis trinerviglvmis Munro 



in Herb.) 



Plant perennial, with slightly thickened tufted base 



Culms erect or geniculate below, rarely branching, terete, hispid, 2 to 3 feet tall 

 Leaves; radical and of radical shoots numerous, with loose, pubescent sheaths 

 and involute, hispid, often pubescent blades, 3 to 6 inches long; of culm 4 to 6 



tW of rr^ ! n lnt r°f eS ' ° Pen aW - Upper <*es nearly smooth; blades like 

 tliose ot radical leaves; ligule an inconspicuous fringe 



Inflorescence a narrow, erect, spike-like panicle, 4 to 8 inches long: branches 

 erect simple almost appressed, } to 2 inches long, or often reduced to single 

 spikelets a little distant, or interrupted. 



Spikelets oblong or oblanceolate, but little compressed, 7- to 9-flowered 3 to 5 

 lines long: ; first glume lanceolate, obtuse or nearly acute, carinate, scarious 7- 



l£Tv £ T ?T' S6C °? d glUme lance - ovate > a ™te, carinate, scarious, sca- 

 b id, hispid on keel, 3-nerved, 21 to 8* lines long; internode of rachilla stout, 

 pubescent, articulate above, | line long; floral glumes oblong-ovate, obtuse, einar- 

 gmate, mucronate or entire at apex, 3-nerved, pubescent below, lateral nerves 

 11 lmes'long ° re reacMng the margin ' palet oyate > obtuse > Pubescent on the 2keels, 

 ^ Grain ovate-conical, deeply hollow on one side, dark-brown, punctate, 1* lines 



Plate XL; a, spikelet; b, and V, empty glumes; c, floral glume dorsal and 

 side views; d, and e, palet, ventral and side views. 



Prevails throughout Texas, westward to Arizona, and northward to Colorado 

 Apparently not of great agricultural importance. Tricuspis mutica Torr. appears 

 to be a smaller form, with shorter, interrupted panicle. 



