GRASS FAMILY 57 



4. C. rubescens Buckley. Cespitose perennial; stem 4-10 dm. high; leaf- 

 blades 5-15 cm. long, involute, scabrous, stiff; panicle strict, spike-like, purplish, 

 5-15 cm. long; empty glumes 4-5 mm. long, acute, minutely scabrous; lemma 

 about as long, awned below the middle. Grassy banks: B.C. — Alta. — Wyo. — 

 Calif. Submont. — Mont. Jl-Au. 



5. C. Suksdorfii Scribn. Tufted perennial; stem 6-10 dm. high; leaf- 

 blades 1-3 dm. lung, mostly involute; panicles 7-12 cm. long, narrow, but not 

 spike-like, often lobed and "interrupted; empty glmnes 3-4 mm. long, acute, 

 pale, and somewhat translucent, nearly smooth; lemma one-fourth shorter, oblong, 

 obtuse, 4-toothed, awned near the base. Open woods and banks: Sask. — Wyo. — 

 Calif.— B.C. Submont.— Mont. Je-Au. 



6. C. luxurians (Kearney) Rydb. Tufted perennial; stem 1-1.5 m. high; 

 leaf-blades flat, 1.5-3 dm. long, 4-5 mm. wide, scabrous; panicle 1-2 dm. long, 

 ovoid, pale, open; empty glumes narrowly lanceolate, acute; lemma one-fourth 

 or one-fifth shorter, nearly glabrous, awn-bearing near the base. C. Suksdorfii 

 luxurians Kearnev. Oiien woods: B.C. — Mont. — ^Colo. — Ida. Submont. Je- 

 Jl. 



7. C. Langsdorfii (Link) Trin. Perennial, with a rootstock; stem 3-6 

 dm. high, erect, simple; leaf-blades 1-3 dm. long, 4-8 mm. wide, scabrous, 

 usually flat and spreading; panicle 5-15 cm. long; empty glumes 4-6 mm. long, 

 long-acuminate, strongly scabrous, lead-colored, brown or purplish; lenima one- 

 fourth shorter, scabrous, awned below the middle. Alpine-arctic situations: 

 Greenl.—X.C— Sask.— N.M.— Calif.— Alaska. Mont.— Alp. Jl-S. 



8. C. canadensis (Michx.) Beauv. Perennial, with a rootstock; stems 5-15 

 djn. high, erect, simple; blades 1.5-3 dm. long, 2-8 mm. wide, scabrous, usually 

 flat; i)anicle 1-2 dm. long, open, usually purple; branches spreading; empty 

 glumes 3-3.5 mm. long, acute, or (in var.. acuminata) 3.5-4 mm. long and acumin- 

 ate, scabrous; lemma slightly shorter, scabrous, awn-bearing near the middle; 

 awn slender, nearlv equalling the glumes. Banks and swamps: Newf. — N.C. — 

 N.M.— Calif.— Alaska. Plain— Subalp. Jl-S. 



9. C. Macouniana Vasey. Perennial; stem 6-10 dm. high, erect, somewhat 

 branched below, leafy; leaf-blades flat, 1.5-2.5 dm. long; panicle 7-10 cm. long, 

 lanceolate or conic, open; spikelets crowded on the upper part of the branchlets; 

 empty glumes about 4 mm. long, purplish, acute, finely scabrous on the back; 

 lemma equalling the empty gliunes. Wet places: Man. — S.D. — Wash. Plain — 

 Subniont. 



10. C. blanda Beal. Perennial, with a rootstock; stem 6-12 dm. high; 

 leafe-blades 1.5-2 dm. long, 4-8 mm. wide, flat, scabrous; panicle 1.5-2 dm. long, 

 loose, spreading; empty glumes about 3 mm. long, long-acuminate, scabrous on 

 the veins; lemma one-fourth shorter, thin, acutely toothed. C. pallida Vasey & 

 Scribn. Wet places: Colo. — -Mont. — Wash. Submont. Jl. 



11. C. Scribneri Beal. Perennial, with a rootstock; leaf-blades flat, 1-2 dm. 

 long, 4-5 mm. wide, scabrous; panicle contracted, lanceolate, 1-1.5 dm. long; 

 branches flower-bearing to near the base; empty glumes brown or purple, about 

 4 mm. long, lanceolate, acute or acuminate, lenima one-fourth shorter; awn 

 attached below the middle, exceeding the lemma. C. duhia Scribn. Wet 

 places: Alta.^Colo. — Wash. — B.C.; Que. Mont. — Subalp. Jl-Au. 



12. C. Cusickii Vasey. Perennial, with a creeping rootstock; stem 10-12 

 dm. high; leaf-blades flat, 1-3 dm. long, 5-8 mm. wide; panicles about 1.5 dm. 

 long, acute, narrow; branches flower-bearing to the ba.se; glumes about 4 mm. 

 long, acute or acuminate, smooth, thin; lemma nearly as long as the empty 

 glumes, acuminate; awn erect, inserted a Uttle below the middle, slightly exceed- 

 ing the lemma. Wet places: Ore. — Ida. — Calif. Jl. 



13. C. scopulorum M. E. Jones. Tufted perennial; stem 3-8 dm. high;^ 

 leaf-blades 1-3 dm. long, 6 mm. wide, flat, pale; panicle narrow, 1-1.5 dm. long; 

 empty glumes about 4 mm. long, white or pale, acute, smooth except on the 

 nerves; lemma nearly as long; awn attached below the middle, shorter than the 

 lemma. Mountains and hills: Utah — Colo. Son. — Mont. Au-S. 



