62 GRAMINEAE (GRASS FAMILY) 



1. Avena fatua L. Sp. PL 80. 1753. A glabrous annual much resembling 

 the common cultivated oat (A. saliva): leaves flat, long, broad and scabrous: 

 panicle open, of few spikelets on filiform unequal rays : spikelets 2-3-flowered : 

 glumes ovate-lanceolate, 20-25 mm. long, with 9 prominent nerves; lemma 

 9-nerved; the awn from near the middle, twisted, abruptly bent near the 

 middle; palet shorter than the glumes, pubescent. WILD OATS. An oc- 

 casional weed in cultivated fields; widely introduced from the Mediterranean 

 region. 



2. Avena striata Michx. Fl. Bor. Am. 1: 73. 1803. Glabrous and smooth 

 throughout, slender, 3-6 dm. high: leaves narrow: panicle simple, loose, with 

 spikelets on capillary pedicels: lower glume 1 -nerved; the upper 3-nerved; 

 flowers short-bearded at base; the soon bent or divergent awn inserted just 

 below the tapering very sharply cuspidate 2-cleft tip of the palet. Colorado 

 to Montana and thence eastward and westward. 



3. Avena Mortoniana Scribn. Bot. Gaz. 21: 133. 1896. A smooth, erect 

 perennial, 1-4 dm. high: ligule ovate, acute; blades narrow, 5-20 cm. long: 

 spikelets 4-5-fl owered : glumes lanceolate, subequal, 3-nerved; lemma 12 mm. 

 long, 5-nerved; the awn near the middle, surpassing the glume by 7-10 mm.; 

 palet shorter than the lemma, keel ciliate. (A . americana Scribn. Bull. Agrost. 

 U. S. Dept. Agr. 7: 183. 1897 may be distinct, but seems rather to be merely 

 the more robust form occurring in the same range.) Colorado to Montana, 

 in the mountains. 



36. DANTHONIA DC. OAT GRASS 



Mostly perennials of strict habit and with either flat or convolute leaves, 

 and open or contracted panicle. Rachilla hairy and extending above the 

 flowers. Spikelets of 3 or more perfect flowers. Glumes subequal, acute, 

 longer than the 7-11-nerved lemmas; awn composed of the 3 middle nerves, 

 flattish and spirally twisted at base, inserted between the sharp-pointed teeth 

 of the lemma. 



Leaves or sheaths or both silky-hairy. 



Spikelets very few or often solitary . . . . . , . 1. D. unispicata. 



Spikelets several to many . . . . . . . . 2. D. californica. 



Leaves and sheaths glabrous. 



Lemma 7-nerved . . . . . . . . . . 3. D. intermedia. 



Lemma 1 1-nerved . ........ 4. D: Parryi. 



1. Danthonia unispicata Munro, Vasey, Cat. Gr. 59. 1885. Culms 1-2 

 dm. high, more or less tufted: leaves in dense radical tufts, sparsely softly 

 silky-villous; the ^heaths densely villous with white spreading hairs, arising 

 in small clusters from minute white papillae: spikelets very few, usually 

 solitary-terminal; otherwise much as in the following. Rather frequent in 

 our range and extending west to California. 



2. Danthonia californica Boland, Proc. Cal. Acad. 2: 182. 1863. Stems 

 sometimes decumbent at base, 5-7 dm. high: leaves, especially the lower, 

 convolute and setaceously pointed, with sheaths silky pubescent and bearded 

 at the throat: panicle mostly a simple raceme: glumes usually purplish with 

 scarious margins, pointed, the upper 5-7-nerved; lemma broad, its teeth 

 about half its own length, with marginal tufts of long silky hairs at or below 

 the middle; awn about equaling the lemma; palet obtuse, hairy on the nerves. 

 Colorado to Montana and west to California. 



3. Danthonia intermedia Vasey Bull. Torr. Bot. Club 10: 52. 1883. Culms 

 2-4 dm. high, leafy below: ligule a hairy ring; blades 15-25 cm. long, mostly 

 narrow, panicle narrow, dense, 3-5 cm. long: spikelets 5-flowered: glumes 

 subequal, 5-nerved, with cross- veins; lemma 7-nerved, sharply toothed, hairy 

 on the margins; palet 2-toothed: grain flattened, obovate. D. spicata, as to 

 this range. Colorado to Manitoba and California. 



4. Danthonia Parryi Scribn. Bot. Gaz. 21: 133. 1896. Very similar but 

 larger in every way, 3-6 dm. high: panicle more lax, of fewer and larger spike- 

 lets: glumes ovate-lanceolate, 3-nerved or at base 5-7-nerved; lemma about 



