40 POACEAE 



long, at last exserted; lateral ones often included at the bas(?; «pikelets 4-5 mm. 

 long, about 1.5 mm. wide, elliptic; outer glumes hispid on the keel and margins, 

 hispidulous on the sides; stamens 3. Leersia oryzoides (L.) Sw. In swamps: 

 N.S. — Fla. — Tex. — Colo. — Sask.; also Eu. Plain — Submont. Au-0. 



15. PHALARIS L. Canary-grass. 



Annuals or perennials. Panicles terminal, cylindric and sj^ike-like, cajjitate, or 

 densely thyrsoidal and somewhat interrupted. Spikelets articulated above the 

 empty glumes, compressed, 1-flowered, crowded. Empty glumes 4, the lower 2 

 persistent, larger than the rest, thin-paleaceous, compressed-keeled, the keel 

 usually more or less winged, sometimes wingless, awnless; third and fourth glumes 

 shorter, very thin and narrowly lanceolate, sometimes reduced to bristles, or 

 rarely one of them wanting; lemma chartaceous, at length indurated, awnless, 

 sometimes pointed, obscurely 3-5-nerved, the midnerve sometimes obsolete, 

 enclosing a faintly 2-nerved palet. Styles distinct; stigmas plumose. 



Outer glumes not winged; inflorescence a narrow panicle. 1. P. arundinacea. 



Outer glumes winged; inflorescence a spike or spike-like panicle. 



Spikelets narrow; third and fourth glumes much reduced; blades subulate-linear, 

 hairy. 2. P. caroliniana. 



Spikelets broad; third and fourth glumes thin, membranous; blades lanceolate, 

 glabrous, rarely sparingly hairy. 3. P. canaricnsis. 



1. P. arundinacea L. Glabrous perennial, with a horizontal rootstock; 

 stem erect, 6-15 dm. high; leaf-blades 1-2.5 dm. long, 6-16 mm. wide; panicle 

 7-20 cm. long, dense, 1-2 cm. thick; sjjikelets 5-6 mm. long; outer glumes 3- 

 nerved; third and fourths glumes less than half as long as the lemma, which is 

 pubescent with long appressed hairs. Wet places: N.S. — N.J. — Nev. — B.C.; 

 Eurasia. Plain — Mont. J^Au. 



2. P. caroliniana Walt. Glabrous annual; stem 3-10 drn. high; leaf- 

 blades 5-15 cm. long, 4-10 mm. wide; })anicle ol>long, 2.5-10 cm. long, 1-1.5 

 cm. thick; spikelets 5 mm. long; outer glumes 3-nerved; third and fourth glumes 

 less than half as long as the lemma, which is acuminate and with long appressed 

 hairs. Wet ground: Fla.— S.C.— Mo.— Colo. — Calif.; Mex. Son. — Aiist. My- 

 Au. 



3. P. canariensis L. Glabrous annual; stem 3-9 dm. high, branched at 

 the base; leaf -blades 5-30 cm. long, 4-12 mm. wide, strongly scabrous; panicles 

 oblong oi ovoid, 1-4 cm. long; spikelets 6-8 mm. long; outer glumes whitish with 

 green nerves; third and fourth glumes broadly lanceolate, about half as long as 

 the pubescent lemma. Waste places: N.S. — Va. — Colo. — S.D.; also Calif. — 

 Ore.; naturalized from Europe and Africa. Plain — Submont. Je-Jl. 



16. TORRESIA R. & P. Sweet Grass, Holy Grass. 



Sweet-scented perennials with rootstocks. Panicles open or contracted. 

 Spikelets 3-flowered, the terminal flower perfect, the others staminate. Empty 

 glumes nearly equal, acute, glabrous. Lemma 2-toothed or 2-lobed, with or 

 without an awn. Stamens in the staminate flowers 3, in the perfect flowers 2. 

 Styles distinct; stigmas j)lumose. [Hicrochloa Gmel. Savastatia Schrank,| 



1. T. odorata(L.) Hitchc. Perennial with a creeping root.stock; stem 3-6 

 dm. high, smooth; lower leaf-blades elongated, 1-2 dm. long, 2-6 nun. wide, the 

 upper ones 1-5 cm. long; ixmicle 5-10 cm. long, its branches spreading or re- 

 flexed; spikelets yellowish brown or pur])lish, 4-6 mm. long: first and second 

 gllumes acute; third and fourth glumes villous and strongly ciliate, awn-pointed. 

 U.odorala (L.) Wahl. H.horcali.s R. <k S. Sa'a.<<lana odorata Scribn. Moist 

 paces and among bushes: Lab. — N.J. — Neb. — Colo. — Ariz. — Alaska; Eur- 

 asia. Submont. — Alp. Je-Jl. 



17. ARISTIDA L. Poverty Grass, \\irk-()rass. 



Tufted perennials, with narrow leaves. Inflorescence ])aiiicuhi'te or race- 

 mose. Spikelets 1-flowered, narrow. Empty glumes 2, niembranous, persist- 

 ent, keeled, awnless, usually longer than the lenmia. The latter firm, narrow. 



