GRASS FAMILY 59 



branous, usually somewhat shining. Lemma thin-membranous, almost hj-aline, 

 entire or toothed, acute, obtuse, or truncate and denticulate at the apex, each 

 laearing a slender dorsal straight or geniculate awn, which is twisted at the base. 

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



Empty glumes not extondinu; boyond the apex of the upper lemma; lower empty glume 

 " 1-nerved; densely ci-spitose tufted perennials. 

 Leaves neither stilf nor pungent. 



A^vn inserted one-tliird 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 flhform, revolute, scarcely 1 mm. 



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



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 exserted 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. D. confinis. 



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



Empty glumes extending l)eyond the apex of the upper lemma. 



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

 the lower l-iierved. 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. elongata. 

 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. J), 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; jianicle short, open, 8-15 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: N.IM.— 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 glimies 3.5-5 

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

 colored. Wet meadows and swamps. Newf.^N.J. — N.M. — Calif.— Alaska. 

 Suhmont. — Subalp. Je-S. 



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

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

 the base often included in the upper sheath; empty glume unequal, 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; em])ty glumes subequal, 3.5-4.5 mm. long, puri)lish, lanceolate, acute; 

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

 lemma. Near hot sjirings: Alta. — Wj'o. Mont. Jl-Au. 



6. D. atropurpurea (Wahl.) Scheele. Perennial, with a cesjiitose 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 apex; awn attached about the middle, 

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

 — N.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; i)anicle very narrow, 1-2 dm. long, with erect 



