Xo. 47. 

 TRISETUM CANESCENS P.ncklc.v. Pn... Acnd. I'liil. lS(iL>. 100. 



Plant pereiiiii:il, loosely tutted, soiucwlKit tliickriicil iii hasc. willi iiinncroiis 

 fibrous roots. 



Culms erect, striate, nearly smooth, H to •'! feet liij:h. 



Lenren from the base, with close, short sheaths and Hat, eanescent blades (i to 10 

 inches lon^'. Jjcaves of cuhii usually .'J; sheaths rather loose, ojjcn above, striate, 

 eanescent or nearly smooth, shorter than the iiiternodes; blades Hat, eanescent, scabrid 

 or nearly smooth, t to t> incliesloug, .'5 lines wide; lit;'ule ovate, erose or lacerate, li to ■! 

 lines long. 



Injlorescence a narrow, somewhat flexuose, rather (dosely flf)wered panicle 6 to 8 

 inches long; rays iriostly in fours or threes at the 10 to 11! nodes of the scabrid or 

 nearly smooth common axis, eiect, slightly scabrid, une<|ual, 2 inclies itv less loug, 

 bearing beyond the middle, or' to the base on the shorter ones, .'5 to 10 spikelets nearly 

 sessile or on pedicels as long as themselves. 



iSpiLclil.s slightly compressed, o to 1 lines long, 2-tlowereil, or with only 1 perfect 

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

 keel, l-nerved, li to 2 lines long; second em]ity glume broadly lanceolate, acute, liis- 

 l)id on the keel above, 3-nerved below, 1 line wide, •> lines long; Horal glume ovate- 

 lanceolate, cleft ^ way from the apex, somewhat chartaceous, membranaceous on tlie 

 mjirgins above, minutely scabrid, obscurely .")-nerved, .'J lines long; awTi attached at 

 base of cleft, liisjiid, twisted and bent, A inch long, hairs of th(^ distinct callus \ liiu", 

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

 2tootlied at the ajjcx, slightly arched, finely eanescent on the two keels, thin, 2^ lines 

 long; grain spindle-shaped, slightly gibbous, light yellow, opa(iue, li lines long. 



Plate XLVII; «, spikelet enlarged 7 times: h. em|ity glumes; <■. Horal glume, 

 florsal view: <l. ))alet, doisal view: c. |>alet and interuode of rachilla, side \iew. 



(_)alifoiiiia to southern Alaska. 



