248 poACE.^i:.. 



subequal, shortly hairy, ovate, l)ristle-pointt'(l or mucroiuito, l-nervcd, 

 1-1.5 mm. long; Honil glume almost hyaline, oval, aeute, pubescent 

 on the margins and keel for the lower two-thirds. ;5-ncrved, 2- 

 toothed, 1.5-'^ mm. long, the awn 2-'^. I nun. long; palea oval, 

 obtuse or abruptly acute when sj)read. nearly as long as its glume. 

 8ee note under J/. Pur/ en' Scribn. 



Mexico, PriiKjU 3!)1), 400. 



Wet ledges, rocky hills, gravel bars or streams. 



30. M. AlamossB Vasey, Coult. Uot. (niz. 10: UO (18!>l). Once 

 distributed as M. inJunuiyrustided Kuntli, Rev. (J rum. 1 : 03 (1829). 



A slender reddish scabrid erect sparingly-ljninched peiviinial, 

 60-80 cm. higli: the nodes tumid. Slu'iitlis two-thirds as long us 

 the intei'nodes; ligule thin, lascerate, about 2 mm. long; l)lades 

 thin, Hat. or convolute, 5-12 cm. long. 1.5-2.5 mm. wide. I'unicles 

 slender, linear or lanceolate. 12-16 cm. long; rays rigid, rather dis- 

 tant, solitary or in twos or threes, branching sparingly and tlower- 

 bearing from near the l)ase. Spikelets subsessile, at length spread- 

 ing, recurved: empty glumes unequal, oval, acute, obtuse or 2- 

 toothed, mucronate with one strong nerve, first about 1 mm. long, 

 second 1.5 mm. long; floral glume shortly hairy for the lower third, 

 scabrid above, linear-lanceolate, 2-toothed, 3-nerved, 2.2-2.5 mm. 

 long, the awn 10-20 mm. long; palea linear-elliptical, acute, ii little 

 shorter than its glume, drain linear-lanceolate, terete, l.;} mm. 

 long. 



^Fexico, Prinfjle 30:, 428, Palmer 407. 



Kocky Hills, under shrubs, etc. 



Texas to Arizona and ^Fexico. 



'21. M. sylvatica ]\Iuhl. A. (Jray, N. A. Oram, and Cyp. No. 

 13 (1834). A. diffusa Muhl. dram. 04 (1817), iu)t Host. 



Culms hard, ascending, much branched and diffusely spreading, 

 60-120 cm. high, from scaly creeping rootstocks. Sheaths id)out 

 the length of the iuternodes; ligule less tluin 1 mm. long: blades 

 flat, thin, scabrous, pungent-pointed, 5-8 cm. long, 3 luni. wide. 

 Panicles spikelike, slender, interrupted, 8-12 cm. long, 5-7 mm. 

 diam., rays mostly in threes, very unequal, the longest slender, 

 spikelike, flower-bearing from near the base. 3-4 cm. long. Spike- 



