Flora of the Palousc Region 2 1 



branous, keeled, the lower i -nerved, the upper 3-nerved and often 

 short-awned: flowering glumes 2, paper}-, that of the upper flower 

 bearing a bent awn; palet narrow: grain oblong, free, enclosed in 

 the scale. 



H. lanatus L. Perennial; the whole plant downy with pale pubescence: 

 culms erect, 30-90 cm. high: leaf blades flat, rather broad and short; sheath 

 loose, shorter than the internodes: panicle pale purplish, '5-10 cm. long, 

 rather densely flowered, the branches in twos or threes: spikelets 4-5 mm. 

 long: upper empty glume short-awned near theapex: glume of the staminate 

 flower with a hook-like awn. Sparingly introduced. 



34. DESCHAMPSIA. 



Inflorescence a contracted or open panicle: spikelets 2-flowered, 

 both flowers perfect, the hairy rachilla extending beyond the flow- 

 ers or rarely terminated by a staminate one: empty glumes keeled, 

 acute, membranous, shining, persistent: flowering glumes 2 (rarely 

 more) of about the same texture, deciduous, bearing a dorsal awn, 

 the apex toothed; palet narrow: grain oblong, free, enclosed in the 

 flowering glume. 



Empty glumes scarcely equalling the flowering glume. D. caespitosa. 

 Empty glumes exceeding the flowering glume. 



Empty glume about 4 mm. long. D. ELONGata. 



Empty glume about 7 mm. long. D. calycina. 



D. caespitosa Beauv. Densely tufted perennial: culms .6-1.5 ni - high, 

 much exceeding the numerous basal leaves: culm leaves 3, the blades nar- 

 row, involute, 5-12 cm. long, scabrous, the smooth sheaths shorter than the 

 internodes: panicle 10-30 cm. long, usually open, the capillary branches in 

 whorls of 2-5, flower bearingabove the middle: spikelets shining, greenish 

 or purplish, 2-3 mm. long: flowering glume hairy at the base, erose-toothed 

 at the apex; bearing a slender awn near the base. Plentiful in wet ground. 



D. elongata Munro. Culms densely tufted, smooth, 30-90 cm. tall: 

 leaves filiform, commonly involute, smooth: panicle narrow, 15-45 cm. long, 

 somewhat nodding; branches very unequal, ascending or appressed, very 

 slender, naked below: spikelets pale green, usually purple-tinged near the 

 apex: flowering glumes hairy at base, shining, irregularly toothed at apex, 

 bearing a slender awn about twice as long. Common in dry soil. 



D. calycina Presl. Annual: the slender culms erect, 15-40 cm. tall: leaves 

 narrow, involute, the blades 2-6 cm. long: panicle very loose, 7-20 cm. long 

 with subequal branches mostly in twos, these capillary, branched above 

 and bearing spikelets near the tips: spikelets pale green, sometimes purple- 

 tinged, about 7 mm. long: flowering glume long hairy at the base, minutely 

 toothed at the apex, bearing a geniculate awn three or four times as long. 

 Very abundant in dry soil. 



35. TRISKTUM. 



Inflorescence a spike-like or open panicle: spikelets 2 4-flowered, 

 the flowers all perfect or the uppermost staminate; rachilla glab- 

 rous or with long soft hairs extended beyond the flowers: empty 



