GRASS FAMILY 59 



branous, usually somewhat shining. Lemma thin-membranous, almost hyaline, 

 entii'e or toothed, acute, obtuse, or truncate and denticulate at the apex, each 

 bearing a slender dorsal straight or geniculate awn, which is t^\'isted at the base. 

 Palet narrow, 2-nerved. Stamens,3. Styles distinct; stigmas plumose. 



Empty glumes not extending beyond the apex of the upper lemma; lower empty glume 

 1-nerved; densely cespitose tufted perennials. 

 Leaves neither stiff nor pungent. 



Awn inserted one-third to one-fifth from the base of the lemma; branches of the 

 inflorescence at last spreading or reflexed. 

 Awns long-exserted, at least half longer than the lemma. 



Empty glumes 3-4 mm. long; leaves flUform, re volute, scarcely 1 mm. 



wide; plant 2-3 dm. high. 1. D. curiifolia. 



Empty glumes 4-5 mm. long; leaves broader and often flat, 1.5-2.5 mm. 

 wide; plant 3-5 dm. high. 2. D. alpicola. 



Awns scarcely e.xserted beyond the lemma. 3. D. caespitosa. 



Awn inserted near the base of the lemma, slightly if at all exceeding it ; branches 

 of the inflorescence ascending. 4. I), confinis. 



Leaves arcuate, strongly involute, very stiff and pimgent. 5. D. pungens. 



Empty glumes extending beyond the apex of the upper lemma. 



Spikelets usually dark piu"ple; empty glumes lanceolate, purple, about 5 mm. long, 

 the lower 1-nerved. 6. D. alropurpurea. 



Spikelets light green; empty glumes linear-lanceolate, both 3-nerved. 

 Spikelets 3-5 mm. long; tufted perennials. 



Leaves filiform-involute; sheaths close; spikelets 3-4 mm. long. 



7. D. elongaia. 

 Leaves involute but not filiform, or the stem.-leaves flat; upper sheaths loose; 

 spikelets 4-5 mm. long. 8. D. ciliata. 



Spikelets 5-8 mm. long; annuals. 9. D. calycina. 



1. D. curtifolia Scribn. Basal leaf -blades 1-10 cm. long, the cauline ones 

 1-2 cm. long; panicle small, 3-10 cm. long, its branches in 2's or 3's, or single, 

 at last spreading; empty glume 3-4 mm. long, lanceolate, acute; lemma nearly 

 as long. D. brevifolia R. Br. D. brachyphylla Nash. Alpine ridges: Colo. — ■ 

 Utah — Mont. Subalp. — Alp. 



2. D. alpicola Rydb. Basal leaf-blades 1-2 dm. long; stem-leaves 1-4 cm. 

 long; panicle short, open, 8-lo cm. long, its branches in 2's to 5's, 3-6 cm. long, 

 soon spreading; spikelets about 5 mm. long; empty glumes lanceolate, acute; 

 lemma nearly- as long, hirsute at the base. Deschampsia caespitosa alpina Vasey. 

 Alpine meadows: X.Al. — -Wyo. — Utah. Mont. — Alp. Jl-S. 



3. D. caespitosa (L.) Beauv. Stem 3-10 dm. high; basal leaf-blades 2-5 

 cm. long, 1.5-3 mm. wide, flat or in drier situations involute, rather firm; stem- 

 leaves 3-10 cm. long; panicles 1-3 dm. long, 5-15 cm. wide; empty glumes 3.5-5 

 mm. long, lanceolate, acute or acuminate; lemma 3-4 mm. long, purple or lead- 

 •colored. Wet meadows and swamps. Xe\\-f. — -N.J. — -N.M. — -Calif. — -Alaska. 

 Suhmont. — Subalp. Je-S. 



4. D. confinis (Vasey) Rydb. Stem 3-9 dm. high, glabi'ous; leaf-blades 

 1-3 dm. long, more or less involute when dr}-; panicle narrow, 1-3 dm. long, 

 the base often included in the upper sheath; empty glume imequal, 4-5 mm. 

 long, lead-colored or purplish with straw-colored margins, lanceolate, acute; 

 lemma nearly as long, lanceolate, acute. Wet places: s Calif. — s Utah — Ariz. 

 Son. Je-Au. 



5. D. pungens Rydb. Stem 3-4 dm. high, glabrous and shining, the base 

 covered with subchartaceous sheaths from preceding season; leaf -blades bluish 

 green or in age straw-colored, scabrous-pruinose; panicle open, with spreading 

 branches; empty glumes subequal, 3.5-4.5 mm. long, purplish, lanceolate, acute; 

 lemma 3-3.5 mm. long, similar; awn attached at the base, about equalling the 

 lemma. Near hot springs: Alta. — ^Wyo. Mont. Jl-Au. 



6. D. atropurpurea (Wahl.) Scheele. Perennial, with a cespitose root- 

 stock; stem glabrous, 1.5-5 dm. high; leaf-blades 2-5 mm. wide, 5-12 cm. long, 

 flat and flaccid; panicle narrow, 2-10 cm. long, with short erect branches; lemma 

 about 3 mm. long, erose-truncate at the ape.x; awn attached about the middle, 

 bent. D. latifolia (Hook.) Vasey. D. Hookeriana Scribn. Wet places: Greenl. 

 — X.H. — Colo. — Calif. — Alaska; n Eu. Subalp. — Alp. Jl-S. 



7. D. elongata (Hook.) Munro. Stem 3-10 dm. high, slender; leaf-blades 

 5-10 cm. long, 1 mm. wide; panicle very narrow, 1-2 dm. long, with erect 



