No. 22. 

 MUHLENBERGIA DUMOSA S(nl)ii. in Vascy, Coutr. Nat. H.tI). iii. 71. 



/'/((;(/ perennial, coarse, tVoni stronj; rootstoek .i incli in dianu^ter. 



Culm cwx't, robust, j;ivin^ otl' tine, solid, woody hraiielies at each node, smooth, 

 shiniii}^, 3 to 6 feet hi}ih. 



Leaves of culm 10 to 20, mostly reduced to open, yellow, searious, smooth sheaths, 

 the convolute blades falling early ; leaves of the branches numerous, with slender invo- 

 lute blades 1 to 2 inches long, promiueutly articulated with the close sheath; ligulea 

 iiunutc, nu'mbranaceous collar. 



Infiorencenve numerous loose panicles I inch long or less, tenuinating the rami- 

 ti(!ations of the leafy, lateral branches. 



Sjiikelcts nearly sessile or on pedicels less than 1 line long; eni])ty glumes ])crsist- 

 ent, divergent, ovate, acute, obtuse or bidentate at apex, cariiuite, nienibranaceous, 

 e.\cei)t the minutely hispid, green, exeurrent midner\'e, sul)c(|nal, '^ line long; floret 

 caducous, linear, the glume and palet slightly dixcrgent at the apcN. ecpial, li lines 

 long; floral glume narrowly ovate, acute, convex, curved bac^kward at tiie apex, mem- 

 branaceous, ciliate below the middle, prondnently .'> nerved, midnersc exeurrent in a 

 minutely hispid awn 1 to 2 lines long; palct lanceolate, nearly acute, linely i)ubescent 

 between the two nerves; grain narrowly cylindrical, reddish-brown, scarcely trans- 

 lucent, roughened, ^ line long. 



T^LATK XXII; ((, si)ikclct eidarged .T times; &, empty glumes showing the vari- 

 ation in the apexes; c, tloral glume; '/. palet. 



^lexico, Arizona and southern California. A strongly rooted, si)rcadiiig grass. 



