742 GRAMINE^E ALOPECUBIS 



DANTHONIA 



A. Howellii Vasey Bull. Torr. Bot. Club, xv, 12. A low tufted an- 

 nual, often purplish throughout: stems erect, or somewhat geniculate at 

 base, mostly simple, smooth, 3-6 inches high: sheaths loose or vaginate, 

 the upper one more inflated, smooth, the lower shorter than the inter- 

 nodes, the upper one exceeding the intern ode, with a short blade : ligules 

 membranous, obtuse, 1 line long: leaves filiform-convolute, exceeding the 

 stem : panicle cylindric, 1 inch long, usually included at base: empty 

 glumes sljghtly united at base, oblong, obtuse, carinate, scarious on the 

 margins, ciliate on the keel and silky on the lateral nerves and near the 

 base, !%-!% lines long: flowering glume broadly ovate oblong, truncate, 

 thin, smooth, 4-nerved, equalling the empty ones: awn arising below the 

 middle of the glume, slender, naked below, bent, 3 lines long: palet want- 

 ing. Margins of small pools that are dry in summer, on the rocky plains 

 near Medford southern Oregon. 



A. occidentalis Scribn. Bot. Gaz. xi, 170. Stems rather slender, 2-3 

 feet high : sheaths loose, shorter than the internodes : leaves flat, 2-4 inches 

 long: panicle oblong, an inch long: outer glumes united at the base, about 

 2 lines long, acute, pubescent with short hairs, the keel ciliate with long 

 hairs : flowering glume a little shorter than the outer ones, glabrous except 

 at the villpus apex : awn inserted below the middle, straight, much exceed- 

 ing the glume. Wet medows and banks of streams, in the high moun- 

 tains, Idaho to Montana and Colorado. 



Tribe 5 Avenese. Spikelets two- to several-flowered. Outer 

 empty glume usually longer than the first flowering one. One or 

 more of the flowering glumes awned on the back, or from between the 

 teeth of the bifid apex. Awn usually twisted or geniculate. Callus 

 and usually the joints of the rachis hairy. 



26 DANTHONIA DC. Fl. Fr. iii, 32. (1805.) 



Mostly perennial grasses with flat or convolute leaves and con- 

 tracted or open panicles. Spikelets 3- to several-flowered, the flow- 

 ers all perfect, or the upper staminate, pubescent, extended be- 

 yond the flowers. Glumes 5 to several, the 2 lower empty, keeled, 

 acute, subequal, persistent, generally exceeding the uppermost 

 flowering one. Flowering glumes rounded on the back, 2 toothed, 

 deciduous, the awn arising from between the acute or awned teeth, 

 flat and twisted at base, bent. Palet hyaline 2-keeled near the 

 margins, obtuse or 2-toothed. Stamens, 3. Styles distinct, with 

 plumous stigmas. Grain free, enclo sed in the glume. 



D. Californica Bolander Proc. Calif, Acad. ii, 182. Stems slender, 

 1-4 feet high, erect, or geniculate at the lower nodes, smooth : leafy nearly 

 so the top : sheaths rather loose, closed at the hairy throat, usually pubses- 

 cent mostly shorter than the internodes : ligules nearly obsolete : leaveoa of 

 the radical shoots numerous, with short sheaths and slender involute brcdes 

 4-8 inches long; of the stem with flat or loosely involute blades, scabn us, 

 especially toward the involute point, often thinly pubescent, 2-5 ie 8 hes 

 long : inflorescence a short simple panicle : spikelets cuneate, comprvsed, 

 5-8-flowe,red : empty glumes lanceolate, with long carinate or in lute 

 points,6-7 lines long: flowering glumes broadly lanceolate, acuminate with 

 2 teeth 1 line long at the apex, smooth except a tuft of pilose hairs on each 

 margin, or often slightly ciliate throughout: awn inserted at the base of 

 the sinus, slightly hispid, often twisted and bent, 3-5 lines long : palet ob- 

 long, 3-toothed at the apex. In moist ground, Washington to California. 



B. intermedia Vasey Bull. Torr. Bot Club x, 52. Densely tufted : 



