414 GRAMINE^. (GRASS FAMILY.) 



striate, rough above and on the margins: panicle an inch or two long, ver^ 

 dense: outer glumes ovate, acute: flowering glume acute, lacerate-f ringed, 

 with numerous delicate basal hairs longer than in the next; awn verij slightly 

 exceeding the glume, attached just above the base, straight. — Calamagrostis Lap- 

 ponica, Trin. Eocky Mountains of Wyoming and northward to Alaska. 



4. D. Stricta, Trin. Stem taller : leaves mostly setaceously involute, erect, 

 scabrous on both sides: panicle at first included at base, at length exserted, 2 to 

 5 inches long, narrow, somewhat lobed, interrupted below : outer glumes ovate- 

 oblong, acute, rough upon the keel and minutely scabrous all over : flowering 

 glume bearing the straight awn at or below the middle and slightly exceeding it ; 

 the hairs at the base about two thirds the length. — Calamagrostis stricta, Trin. 

 From the mountains of Colorado to California, and eastward along the north- 

 ern border to Vermont and Canada. 



6. D. sylvatiea, DC. Stems l to 2 feet high, clothed at base by crowaed 

 dead sheaths : radical leaves reaching nearly to the panicle ; stem leaves 

 gradually becoming shorter, all attenuate-pointed, more or less scabrous and 

 involute : panicle enclosed at base when young, spike-like, 3 or 4 inches long, 

 very dense ; rays mostly in fives, appressed and like the rhachis very rough : 

 outer glumes ovate-lanceolate, very acute : flowering glume acute, 4-toothed, 

 grooved on the back, its awn attached very near the base, twisted and rough 

 below, bent at the middle, and exserted more than half the length of the glumes ; 

 hairs unequal, the longest at the sides about ^ as long as the glume. — Calama- 

 grostis sylvatiea, DC. Mountains of Colorado, thence northward and west- 

 ward. 



23. DESCHAMPSIA, Beauv. Hair GRAfes. 



Perennials, formerly included under Aira as a subgenus. The flowering 

 glume is delicately 3 to 5-nerved, and the grain is free. 



* Outer glumes barely equalling and mostly shorter than the florets. 



1. D. flexuosa, Beauv. Stem slender, 1 to 2 feet high, nearly naked 

 above the small tufts of involute bristle-form root-leaves ( 1 to 6 iuches long) : 

 panicle small and spreading, its branches capillary : awn longer than the glume, 

 at length bent and tivisted. — Aira flexuosa, L. Mountains of S. W. Colorado 

 (Brandegee) and northward; common in the Atlantic States. 



2. D. csespitosa, Beauv. Stem tufted, 2 to 4 feet high: leaves flat and 

 linear: panicle 6 inches long, pyramidal or oblong : awn straight, barely equal- 

 ling the qlume. — Aira ccespitosa, L. Across the continent and northward to 

 Alaska. Very variable, especially the mountain forms. The dwarf moun- 

 tain plant, 6 or 8 inches high, with a tuft of short setaceous leaves, is var. 



arctica. 



* * Outer glumes longer than the florets. 



3. D. danthonioides, Munro. Stem slender, from a few inches to 

 2 feet high: leaves very narrow: panicle very loose and open: outer glumes 

 linear-lanceolate : flowering glume ivith hairs at base I as long, shining below ; 

 awn inserted just below the middle, about 3 times its length, light brown, 

 twisted below and geniculate near the middle. — Aira danthonioides, Trin. 

 From Texas to Colorado, California, and Oregon. 



