No. 47. 

 TRISETUM CANESCENS Buckley, Proc. Acad. Phil. 1862. 100. 



Plant perennial, loosely tufted, somewhat thickened at base, with numerous 

 fibrous roots. 



Culms erect, striate, nearly smooth, 2 to 3 feet high. 



Leaves from the base, with close, short sheaths and flat, canescent blades 6 to 10 

 inches long. Leaves of culm usually 3; sheaths rather loose, open above, striate, 

 canescent or nearly smooth, shorter than the internodes ; blades flat, canescent, scabrid 

 or nearly smooth, 4 to 6 inches long, 3 lines wide ; ligule ovate, erose or lacerate, 2 to 3 

 lines long. 



Inflorescence a narrow, somewhat flexuose, rather closely flowered panicle 6 to 8 

 inches long; rays mostly in fours or threes at the 10 to 12 nodes of the scabrid or 

 nearly smooth common axis, erect, slightly scabrid, unequal, 2 inches or less long, 

 bearing beyond the middle, or to the base on the shorter ones, 3 to 10 spikelets nearly 

 sessile or on pedicels as long as themselves. 



Spikelets slightly compressed, 3 to 4 lines long, 2-flowered, or with only 1 perfect 

 flower ; first empty glume narrowly ovate, acute, slightly carinate, thin, hispid on the 

 keel, 1-nerved, 1£ to 2 hues long; second empty glume broadly lanceolate, acute, kis- 

 j)id on the keel above, 3-nerved below, 1 line wide, 3 lines long; floral glume ovate- 

 lanceolate, cleft £ way from the apex, somewhat chartaceous, membranaceous on the 

 margins above, minutely scabrid, obscurely 5-nerved, 3 lines long; awn attached at 

 base of cleft, hispid, twisted and bent, \ inch Jong, hairs of the distinct callus \ line 

 long; internodes of rachilla villose, 1 to 2 lines long; palet lance-oblong, minutely 

 2-toothed at the apex, slightly arched, finely canescent on the two keels, thin, 2£ lines 

 long; grain spindle-shaped, slightly gibbous, light yellow, opaque, 1£ lines long. 



Plate XLYII ; a, spikelet enlarged 7 times ; b, empty glumes : 

 dorsal view ; d, palet, dorsal view ; e 1 palet and internode of rachilla, side view. 



California to southern Alaska. 



