1242 poacetE. 



first lanceolate, 1-nerved, about 1.5 mm. long, second much broader. 

 2 mm. long, 3-nerved, and acutely 3-tootbed; floral glume 3 mm. 

 long, pilose below at the back and sides, scabrous above, awned just 

 below the entire or bidentate apex; awn 8-12 mm. long, strongly 

 flexuose. For another description see Scribner in Phil. Acad. Sci. 

 1891, p. 297. 



Mexico, Bourgeau 1155, Pringle 3316. 



7. M. gracilis (H. B. K.) Trin. Unifl. 193 (1826). Podo- 

 scBmum gracile H. B. K. Nov, Gen. et Sp. 1:131 (1815). 



An erect pale rigid tufted perennial, 15-60 cm. high. Sheaths 

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

 long, withered sheaths of the sterile shoots numerous; blades 

 usually involute-filiform, scabrous, 6-10 cm. long, 1-2 mm. wide. 

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

 rays usually single, appressed, flower-bearing 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 1-2-3-nerved 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 1.6 mm. long. 



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

 Pringle 392, 393. 



British America to Mexico. 



Var. breviaristata A^asey, Contrib. U. S. Xat. Herb. 3 : 67 

 (1892). iM. subalpina 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. Empty glumes distant, destitute of 

 nerves or the second obscurely nerved. 



Mexico, Pringle 1413. 



8. M. virescens (H. B. K.) Trin. Unifl. 193 (1826). Podo- 

 ^cemum virescetis H. B. K. Nov. Gen. et Sp. 1 : 132 (1815). 



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



