2M ruAi'K.K. 



puhosociil iihovo iiiid below, 4-<) vm. long, 1-1. 5 nun. wide. I'an- 

 ic'li' ot'len iiieliulod at the base by tlie iiijpei* sheath, slender, race- 

 mose, S-IT) em. long, rays mostly solitary, erect or spreading, dis- 

 tinct, distant. S[)ikelets mostly snbsessile and extending the whole 

 length of the branches, )i-{i mm. long; empty glnmes ovate, 1- 

 uerved, subecpnil or the lirst shorter, 0. ")-(». S mm. long; lloral 

 glume 3-4 mm. long, scabrous, H-nerved, linear-lanceolate, the slen- 

 der awn 3-.'} cm. long; ])alea scabrous, lanceolate, little shorter than 

 its glume. (Jrain l.fJ mm. long. 



Arizona, PriiKjlv; California, T. S. Ikpt. Jffn'cuL 310 from 

 Jones, Orcuif; Mexico, /'alincr 510. 



Texas to California and Mexico. 



30. M. spiciformis Trin. Fund. Agrost. 2:42 (1841). Mem. 

 Acad. St. I'etersb. (VI.) 6, 2:2^') (184.")). 



A very slender, much-branched and dilfuse annual, 30-GO cm. 

 high, sheaths smooth, half to three-fourths the length of the intcr- 

 nodes; ligule 1 mm. long; blade thin. Hat. 0-10 cm, long, 1.5-2 

 mm. wide. In some of the lower axils are short turgid sheath-like 

 bracts containing fertile flowers with hyaline glumes. Above are 

 fdiform Ijranches bearing each a single spike, M-15 cm. long with 

 more or less distant spikelets which are single or branching once or 

 twice. Terminal panicles thin, linear, 10-15 cm. long, rays in 

 twos or single, the longest 2-3 cm. long, bearing short branches and 

 10-20 spikelets, snbsessile or on ]iedicels 2-3 mm. long. Eni])ty 

 glumes of these spikelets 1-nerved. the second less than 1 mm. long, 

 but longer than the iirst; lloral glume thiidy ])ilose on the lower 

 half of the central nerve and the margins, scarcely 3 mm. long, gra- 

 dually tapering into an awn 1-2 cm. long; i)alea2 mm. long, grain 

 nearly as long as the palea. Sessile spikelets borne on a bearded 

 pointed callus 2 mm. long in tlie axils of stiif lanceolate bracts 

 about their own length, first glume awl-shaped, 1-3 mm. long, sec- 

 ond linear-lanceolate. mm. long, with a single double nerve; lloral 

 glume as long as the secoiul glume, 3-nerved; ])alea pilose, rachilla 

 constricted, 1-2 mm. long, bearing 3 awns 5-10 mm. long. 



Mexico. 



31. M. brevifolia Scribn. ined. 



