A({U()STI1)K.E. 261 



;3-G mm. long; palea as long as its gLi. torminating in two seta\ 

 Grain linear, terete, 'Z mm. long. 



Arizona (Santa Catilina Mts.), Pringle S84. 



Var. minor Seribn. ined. Plant more slender, spikelets pedicel- 

 late, the bristles of the empty glumes often as long as the rest of 

 glume, lloral glume 2 mm. long, the awn more slender, often 10 mm. 

 or more long. 



^lexico. Pn'u(/Ic '2'-)i')'). 



44. M. arenicola Buekl. Proc. Phila. Aead. 91 (186'3). JA C(pf<- 

 pifom Chapm. Coult. liot. (ias. 3: 18 (1S|8). .)/. xctifitlia Vasey, 

 C'oult. Hot. (Jaz. T:l>-,' (1882). J/. L\rerc/iuni V. t\: S. C'outrib. 

 U. S. Nat. Herb. ;5:G(] (1882). 



A slender erect tufted simple glaucous-green perennial, ;50-G0 

 cm. high, with fibrous roots. Sheaths half the length of tiie inter- 

 nodes; ligule thin, 4-T mm. long: leaves of sterile shoots short, 

 blades conduplicate, rigid, almost fdiform, 8-1.") cm. long. I'anicle 

 terminal, slender, dilTuse, the base sometimes included, ".'O-IIO cm, 

 long, rays in twos or threes, capillary, s])aringly ilowercd on short 

 branches above the middle. Spikelets on pedicels 1-10 mm. long; 

 empty glumes oval to lanceolate or bristly pointed, subequal. 1- 

 nerved, one-fourth to two-thirds as long as the lloret; iloral glume 

 thin, shortly hairy on the nerves for the lower two-thirds, linear, 

 '^-toothed, 13-nervcd, ',] mm. long, awn 1-3 mm. long; palea linear, 

 )i-toothed as long as its glume. 



Mexico, Prinyle from I^itterson. 



Texas, Wri(//i(, Rcrcrr^nn. Ilovarth Xeallcy. 



Texas and ^lexico. 



45. M. gracillima Torr, Pacif. Rail. Pej). 4:155 (1857). 



A slender glabrous densely-tufted perennial. '.'0-40 cm. high. 

 Ligule 3 mm. long; blades of sterile shoots numerous, conduplicate, 

 2-5 em. long. 0.3 mm. diam., those of the culm 2-3 in number and 

 nnu'li the same. Panicle (-'.nder. often purple. ]nrami(lal or con- 

 tracted, about 15 cm. long, rays ca{>illary. mostly solitary, the 

 lower in twos and threes, sparingly branched, the longest 5-0 cm. 

 long, bearing 4-8 spikelets above the middle. Si)iki'lcts on pedi- 

 cels 4-10 mm. long, empty glumes thin, equal, 1-nerved, lanceolate. 



