ii42 I'OACE.K. 



first lanceoliito, l-iiervod, about l.5n)in. loiij:^, second niiicli broiider. 

 2 mm. loiif?. 3-n('rvctl, iiiul iicutely ;5-tootlu'(l ; lloriil j,'lumo ."{ mm. 

 loiifj, pilose below iit tlio buck imd sides, aciibroius above, awned just 

 below tlie entire or bidi'ntatc! apex; awn S-12 mm. lon<,'. stroiifjly 

 llexuoao. For another deacriptiou see Scribuer in IMiil. Acad. Sci. 

 1891, p. 2!»7. 



Mexico, lionrf/vdii 1155, I'rini//r .iAU). 



7. M. gracilis (II. M. K.) Trin. Unill. 1!)3 (KS-.'G). J'odo- 

 smmum {jracHe II. H. K. Nov, Gen. et Sp. 1 :131 (1S15). 



An erect pale ri;,'id tufted perennial, 15-60 cm. Iii<ih. Sheatlis 

 ronghish, longer than the internodes; ligule 5-10 mm. or more ( I) 

 long, withered sheaths of the sterile .shoots numerous: blades 

 usually involute-fdiform. scabrous, (i-10 cm. long, l-;i mm. wide. 

 Panicle very narrow, becoming dark with age, 8-15 cm. long, 

 rays usually single, ap{)ressed, ilower-l)earing for nearly their whole 

 length. Spikelets sessile or pedicellate; empty glumes very vari- 

 able, more or less acute, first usually the shorter, second obtuse, 

 erose or with several teeth, sometimes first and second both termi- 

 nating in l-2-!3-uerved awns, 2-3 mm. long; floral glume with a 

 short callus, bearded at the base, more or less pubescent, 3-nerved, 

 3.5 mm. long, the awn 8-20 mm. long. Grain l.G mm. long. 



Arizona, U. S. Dept. Ayricul. 316; Texas, Jones; Mexico, 

 Pringle 392, 393. 



British America to Mexico. 



Var. breviaristata \'asey, Contrib. U. S. Nat. Herb. 3 : 07 

 (1892). M. HuhalpiHit Vasey, Cat. Gram. U. S. 40 (1885). 



Slender, 18-30 cm. high; panicle about 5 cm. long; awn 2-4 

 mm. long. 



Colorado, Vasey, 642; New Mexico, Vasey in 1889. 



High altitudes. Colorado, New Mexico to Wyoming. 



Var. enervis Scribn. ined. Em})ty glumes distant, destitute of 

 nerves or the second obscurely nerved. 



Mexico, Pringle 1413. 



8. M. virescens (tl. li. K.) Trin. Fnifi. 193 (1826)> Podo- 

 smmum virescens II. 13. K. Nov. Gen. et Sp. 1 : 132 (1815). 



A slender tufted erect perennial, 10-70 cm. bigh. Sheaths 



