52 



POACEAE 



■ 5. S. fiexuosus (Thurb.) Rydb. Tufted perennial; stem 3-8 dm. high; 

 leaf-blades 5-20 cm. long, 2-4 mm. wide, usually fiat, somewhat scabrous above; 

 inflorescence 2-4 dm. long; branches 3-6 cm. long, spreading or refiexed; spike- 

 lets about 2 mm. long, usually lead-colored; empty glumes lanceolate, somewhat 

 scabrous. Sandy soil: Tex. — Xev. — Ariz.; Mex. Son. Jl-S. 



6. S. cryptandrus (Torr.) A. Gray. More or less tufted perennial; stem 4- 

 10 dm. long, erect, glabrous; leaf-blades 7-15 cm. long, 2-4 mm. wide, flat, glab- 

 rous beneath, scabrous above; panicle 1.5-2.5 dm. long; spikelets lead-colored, 

 2-2.5 mm. long; glumes scabrous on the keel. Sandy soil: Mass.— Pa. — Ariz. 

 — Wash.; Mex. Plain — Siibmont. Au-0. 



7. S. heterolepis A. Gray. Tufted perennial; stem 3-10 dm. high, erect; - 

 leaf-blades involute, glabrous, with rough margins and midribs, 2-5 dm. long; 

 panicle 7-25 cm. long, open, exserted; branches ascending; glumes smooth and 

 glabrous, the first one subulate, 2-3 mm. long, the second lanceolate, 4-5 mm. 

 long, awn-pointed; lemma obtuse or acute. Dry soil: Que. — Pa. — Tex. — S.D. 

 — Sask. Plain — Submont, Au-S. 



8. S. asperifolius (Nees & Meyen) Thurb. Perennial with a cespitose 

 creeping rootstock; stem 1-5 dm. high, erect from a decumbent base; leaf-blades 

 2.5-10 cm. long, 2-3 mm. wide, flat, very scabrous above; panicles 7-20 cm. long, 

 usually included at the base; branches usually spreading in age; spikelets 1.5 

 mm. long; glumes acute, glabrous, somewhat scabrous; lemma slightly exceeding 

 them. Sandy or dry soil: Sask. — Mo. — Tex. — Calif.— B.C.; Mex. Plain — Sub- 

 mont. Je-S. 



9. S. texanus Vasey. Tufted perennial, otherwise resembling S. asperifolius; 

 stems rigid; leaf -blades 2.5-7.5 cm. long, scabrous above; panicle half the length 

 of the plant, included in the sheath below; lower gUmie half as long as the second 

 one, which is fully as long as the lenima. Plains: Tex. — Okla. — s Colo.— N.M, 

 Son, 



10. S. confusus (Fourn.) Vasey. Tufted annual; stem 1-3 dm. high, slender, 

 branched below; sheaths short, loose, glabrous; leaf-blades 1-1 cm. long, 0.5-1.5 

 mm. wide; panicle open, 3-20 cm. long; branches spreading; spikelets 1-1.5 

 mm. long; empty glumes shorter than the lemma, glabrous or pubescent; lemma 

 pubescent. Meadows especially in sandy soil: Neb. — Tex. — Ariz. — Ida.; Mex. 

 Son. — Submont. Jl-S. 



28. POLYPOGON Desf. Beard-grass. 



Annuals or rarely perennials. Inflorescence a dense, contracted, spike-like 

 panicle. Spikelets articulate below the empty glumes, crowded, 1-flowered. 

 Flowers perfect. Empty glumes about equal, each terminating in a slender 

 awn. Lemma thin, emarginate or 2-toothed at the apex, awned or awn -pointed 

 on the back. Stamens 1-3. Styles short, distinct; stigmas plumose. 



1, P. monspeliensis (L.) Desf. Simple annual; stem 1-6 dm. high, erect or' 

 decumbent at the base; leaf-blades 4-15 cm. long, 3-6 mm. wide, scabrous; 

 panicle 2-10 cm. long; empty glumes about 2 mm. long, bearing a more or less 

 bent awn 4-6 mm. long; lemma shorter, erose-truncate, hyaline; awn 0.5 mm. 

 long. Waste places: S.C.—X.H.— B.C.— Calif.; Mex.; naturalized from Eurasia. 

 Plain-Submoni. Ap-Au. 



29. CINNA L. ^Reed-grass. 



Tall perennials with broad flat leaves. Inflorescence a large often nodding 

 panicle. Spikelets numerous, 1-flowered, articulate under the empty glumes. 

 Flowers perfect. Empty glumes 2, persistent, keeled, acute. Lemma similar, 

 shorl-awned or awn-pointed just below the apex. Palet 1-nervcd, keeled, the 

 keel minutely ciUate. Stamen 1, Styles short, distinct; stigmas plumose. 



1. C. latifolia (Trev.) Griseb. Stem 6-15 dm. high, erect; leaf-blades 1-2.5 

 dm. long, 4-12 mm. wide, scabrous; panicle 1-2.5 dm. long; spikelets 3 mm. long; 

 empty glumes equal, acute, hispid ulous on the keel; lemma somewhat shorter, 

 2-toothed at the apex; Viwn 1-2 mm. long. Cinna pendula Trin. Damp woods: 

 ]Sewf.—X.C.— Utah— B.C. Submont.— Mont. Jl-S. 



