294 GRAMINE^E. Danthonia. 



2-toothed and more or less distinctly awned. Gram. Mex. Bound, ined. ; Boland. 

 in Trans. Calif. Agric. Soc. 1864-65, 137, without description. 



Fort Mohave and Providence Mountains (Cooper) ; Fort Yuma (Major Thomas) ; Colorado Desert, 

 (A. Schott), and along the Gila River. A striking species on account of its rigid woody stems, in 

 habit resembling some of the dwarf Bamboos. Regarded as valuable forage, at least for mules, 

 which eat its almost woody stems with avidity. The pubescence of the culms within the sheaths 

 is singularly matted and dense and very white. 



32. DANTHONIA, DC. WILD OAT-GRASS. 



Panicle loose or often a simple raceme. Spikelets several- (about 7-) flowered. 

 Glumes about equal, keeled, unawned, as long as or longer than the flowers. Rhachis 

 of spikelets hairy. Lower palet rounded on the back, 7 9-nerved, terminating in 

 two sharp usually rigidly awl-pointed teeth, between which is an awn flattened be- 

 low and spirally twisted, formed from the three middle nerves. Upper palet broadly 

 2-nerved, equalling or exceeding the entire portion of the lower. Stamens 3. Scales 

 2, somewhat fleshy, entire. Ovary smooth, stipitate. Grain not adherent to the 

 palets. 



A genus of over 100 species, especially abundant in Africa ; a few belong in the Atlantic States 

 and one is peculiar to the western coast. Mostly perennials. 



1. D. Californica, Boland. Culms sometimes decumbent at base, from | to 3 

 feet high : leaves, especially the lower, convolute and setaceously pointed ; ligule 

 obscure ; sheaths rather loose, bearded at the throat : panicle mostly a simple raceme, 

 the usually 3 to 5 (rarely 10) solitary rough-hairy pedicels scarcely as long as the 

 broad spikelets : glumes mostly purplish with scarious margins, pointed, 8 to 10 

 lines long, the upper 5 7-nerved : lower palet broad, shining on the back, coriaceous 

 below, its teeth about half its own length, obscurely 9-nerved, with marginal tufts 

 of long silky hairs ^at or below the middle ; awn about equalling the palet, brownish 

 below ; upper palet ciliate, notched above. Proc. Calif. Acad. ii. 182 ; Watson, 

 Bot. King Exped. 392. 



Var. unispicata. Culms 6 inches high or less, from dense tufts of somewhat 

 hairy leaves, the sheaths of which are densely villous with white spreading hairs 

 about 2 lines long, arising in small clusters from minute white papillae : spikelet 

 solitary and terminal (rarely 2 or 3), usually fewer-flowered than in the type. D. 

 unispicata, Munro in Herb. D. spicata (?), Thurb. in Bot. Wilkes Exped. 488. 



Both forms occur from San Diego to San Francisco (Bolandcr, Parry, Lem.rn.on} ; also in Ore- 

 gon and in the Rocky Mountains. The same large tuft often produces both tall and short culms 

 of the typical form. Some Rocky Mountain specimens, with the several-flowered panicle of the 

 type, have hairy sheaths, but less so than in the variety. 



2. D. sericea, Nutt. Culms not tufted, 1 to 3 feet high : leaves narrow, with 

 sheaths silky-hairy at the throat : panicle narrow, the lower rays sometimes 2-3- 

 flowered and spreading ; spikelets 6 to 8 lines long, the acuminate glumes much 

 exceeding the florets : lower palet with very long teeth, and villous with long silky 

 hairs all over or only below and on the margins. Gen. i. 71 ; Gray, Man. 640. 



Yosemite Trail, at 8,000 feet altitude, Bolandcr, n. 6104. This agrees with the eastern plant, 

 excepting that the lower palet is less copiously hairy. Specimens that have been referred to 

 D. spicata, Beauv., belong to D. Californica. Should that species be met with it will be known 

 by its very short leaves, its small narrow spikelets, only 3 to 5 lines long, and its coarsely hairy 

 lower palet with short and pointless teeth. 



33. A VENA, Linn. OAT. 



Panicle loose and few-flowered. Spikelets large, of few (3 to 5) florets, of which 

 the uppermost is imperfect. Glumes nearly equal, often exceeding the florets, many- 



