CIILUHIDE.E. 425 



tubercles, sheaths loose, longer than the internodes; ligulea frinn;e 

 of hairs; blades flat, 3-0 cm. long, 3 mm. wide. Panicle racemose, 

 3-5 cm. long, bearing 3-5 spikes 1 cm. long, besides the awns, 

 each consisting of 3-4 spikelets. Spikelets 2-flowered ; emjjty 

 glumes 1-nerved, first 5 mm. long, second 6-7 mm. long, the latter 

 scabrous on the keel; floral glume of lower floret oblong-lanceolate, 

 6 mm. long, 5-nerved, lateral awns extending to the ti2)s of the slen- 

 der teeth, central awn about 1.5 mm. long; palea as long as its glume, 

 2-toothed. Grain obcompressed, 4 mm. long. Sterile floret about 



5 mm. long, the three awns subequal, about 8-10 mm. long. 



Mexico (Sonora), Palmer 698, on rocky ridges. 



18. B. aristidoides (Kunth) Griseb. Fl. lirit. W. Ind. 53? 

 (1804). Dinebra aristidoide.s II. IJ. K. Nov. Gen. 171, f. 095 

 (1815). Eutriana aristidoides Trin. Unifl. 243 (1824); Kunth, 

 Kev. Gram. 1:95(1821)). 



A slender tufted annual (?), 10-30 cm. liigh. Loaf-blades 

 rough with slender scattered hairs on the upper side, 2-4 cm. long, 

 less than 2 mm. wide. Spikes 5-10 in number, 1-15 cm. long, 

 more or less hairy, usually spreading on one side of an axis, 4-0 cm. 

 long. Spikelets narrow, appressed to the liairy rachis. 2-3 to a 

 spike, the lower with no awns, the upi)er with awns projecting; 

 empty glumes lanceolate, 1-uerved, first 2 mm. long, with a seta 1 

 mm. or more long, second pubescent with no seta; floral glume of 

 the lower spikelet about 5 mm. long, oval-lanceolate, central seta 

 very short, lateral ones obsolete; palea as long and as wide as its 

 glume, seta^ very short. No empty glume or seta above. (J rain 

 linear. 2.5-3 nnn. long. Floral glume of the second and third spike 

 lets like the floral glume of the lower spikelet; rachilla slender, 1.5 

 mm. long, hairy in midtlle or above, bearing 3 seta?, the lateral ones 



6 mm. long, the central a little shorter, bearing near its base two 

 short slender lateral lobes or not. 



Mexico, Parr II cC Palmer 941, Palmer 51, 162, 1353. 

 Arizona, Pr ingle, California, Palmer 400, 543. 

 Texas, New Mexico, Arizona, southern California, and ^lexico. 

 Alow diffuse and firm-stemmed annual appearing scattered over 



