248 POACE.E. 



subeqiial, shortly liairy, ovate, bristle-pointed or mucronate, 1-nerved, 

 1-1.5 mm. long; floral glume almost hyaline, oval, acute, pubescent 

 on the margins and keel for the lower two-thirds, 3-nerved, 2- 

 toothed, 1.5-2 mm. long, the awn 2-2.1 mm. long; palea oval, 

 obtuse or abruptly acute when spread, nearly as long as its glume. 

 See note under 3L Porteri Scribn, 



Mexico, Pringle 309, 400. 



Wet ledges, rocky hills, gravel bars oi' streams. 



20. M. Alamosae Yasey. Coult. Bot. Gaz. IG: 14G (1891). Once 

 distributed as M. (■(damagrostided Kuntli, Eev. Gram. 1:63(1829). 



A slender reddish scabrid erect s}iaringly-br;inched perennial, 

 60-80 cm. high; the nodes tumid. Sheaths two-thirds as long as 

 the internodes; ligule thin, lascerate, about 2 mm. long; blades 

 thin, flat, or convolute, 5-12 cm. long. 1.5-2.5 mm. wide. Panicles 

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

 tant, solitary or in twos or threes, brandling sj^ariugly and flower- 

 bearing from near the base. Spikelets subsessile, at length spread- 

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

 toothed, mucronate witli 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, a little 

 shorter than its glume. Grain linear-lanceolate, terete, 1.3 mm. 

 long. 



Mexico, Pringle 397, 428, Palmer 407. 



Kocky Hills, under shrubs, etc. 



Texas to Arizona and ]\rexico. 



21. M. sylvatica Muhl. A. Gray, X. A. Gram, and Gyp. No. 

 13 (1834). A. diffum Muhl. Gram. 64 (1817), not Host. 



Culms hard, ascending, much liranched and dilfusely spreading, 

 '60-120 cm. high, from scaly creeping rootstocks. Sheaths about 

 the length of the internodes; ligule less than 1 mm. long; blades 

 flat, thhi, scabrous, pungent-pointed, 5-8 cm. long, 3 mm. 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- 



