82 POACEAE 



obtuss, nearly 4 mm. long, puberiilent, somewhat villous towards the base. P. 

 incurva Scribn. & Merr. P. teninfolin Buckley, in part. Plains and hills: Sask. 

 — Wyo.— Colo.— Utah— n Calif.— B.C. Suhmorit.—Mont. Je-Jl. 



63. P. juncifolia Scribn. Stem glabrous 1.5-3 dm. high; blades of the 

 sterile shoots about 5 cm. long, involute; those of the stem 2-5 cm. long, 1-2 

 mm. wide; panicle narrow; spikelets 3-5-flowered, 5-6 mm. long; empty glumes 

 ovate, usually obtuse, subequal, 3-4 mm. long; lemma minutely scabrous on 

 the back, 3-4 mm. long, obtuse. Plains and meadows: Wyo. — -Colo. — -Utah. 

 Plain — Suhmonl. Jl-Au. 



64. P. brachyglossa Piper. Stem glabrous, smooth, 6-10 dm. high; ligules 

 short, truncate; leaf-blades 5-20 cm. long, filiform, involute; panicle narrow, 1-2 

 dm. long; spikelets 7-10 mm. long, 3-6-flowered; empty glumes smooth, scarious- 

 margined, 4-5 mm. long, .slightly unequal; lemma obtuse, smooth or nearly so. 

 Plains and meadows: B.C. — ^n Calif. — -Mont. Son. — Submonl. Je-Jl. 



65. P. confusa Rydb. Stem 6-9 dm. high; basal leaf-blades 1-2 dm. long, 

 2-3 mm. wide, flat or involute, puberulent; stem-leaves several; blades about 1 

 dm. long; panicle narrow, 1-1.5 dm. long, dense; spikelets 7-8 mm. long, usually 

 4-flowered; empty glumes lanceolate, shining, minutely strigulose above; lemma 

 narrow, about 3.5 mm. long, yellowish green, with brownish scarious margins. 

 Meadows and benchlands: Alta. — Neb. — 'Colo. Plain — Mont. 



66. P. truncata Rydb. Stem about 9 dm. high, stiff; leaf -blades 1-2 dm. 

 long, 2-3.5 mm. wide, scabrous on the back; panicle about 1.5 dm. long, narrow; 

 spikelets 3-5-flowered, 7-9 mm. long; emjity glumes 5-6 mm. long, tinged with 

 purple, scabrous on the nerves; lemma narrow, about 5 mm. long, straw-colored 

 or tinged with purple, strigulose throughout. Hills and gulches: Colo. — Alta. 

 Suhrnonl. Jl-Au. 



67. P. ampla Merr. Stem 6-15 dm. high; leaf-blade-s, flat, somewhat 

 glaucous, 15-25 cm. long, about 4 mm. wide; panicle 2-3 cm. thick and 1.5-3 dm. 

 long; sjiikelets 7-10 mm. long, 3-6-flowered; empty glumes lanceolate, acute, 

 scabrous on the keel and nerves; lemma 4.5-5 mm. long, lanceolate, scabrous 

 throughout, hispidulous on the keel. P. laeviculmis Williams. Hills and val- 

 leys: B.C. — Ore. — Mont.— Ida. Submonl. Je-Jl. 



65. SCOLOCHLOA Link. 



Tall, aquatic perennials. Inflorescence paniculate. Spikelets 2-4-flowered; 

 flowers perfect. Empty glumes 2, thin-membranous, 3-5-nerved. licmma 

 rigid, with a ring of hairs at the base, rounded on the back, 5-7-nerved. Palet 

 usually equalling the lemma, 2-nerved. Styles very short; stigmas plumose. 

 Grain hairy at the apex. 



1. S. festucacea (Willd.) Link. Stem 1-2 m. high, smooth; leaf-blades 

 1.5-4 dm. long, 4-8 mm. wide, flat, scabrous on the margins; panicle open, 2-3 

 dm. long; spikelets 6-8 mm. long; em))ty glumes acute, unequal, 3-5-nerved, 

 6-8 mm. long; lemma narrow, 5-6 mm. long. In water: Iowa — -Neb. — ^Sask. — ■ 

 Ore.— B.C. Plain. Jl-Au. 



66. PANICULARIA Fabr. Manna-grass. 



Usually perennials with rootstock.s (all ours), rarely annuals. Inflorescence 

 paniculate. Spikelets usually numerous, ovate to linear, few-many-flowered, 

 the glabrous racliilla articulate between the flowers. Emj)t>- glumes 2, obtuse 

 or acute, uneciual. Lenmia ol)tuse or truncate, often denticulate, convex on 

 the back, but not keeled, pronun(>ntly nerved, hj'aline at the apex. Palet 2-keeled. 

 Styles short, distinct; stigmas plumose. [Glyceria R. Br.] 



Spikelets ovate or oblong, 6 mm. long or less. 



Lemma 7-nervefI, obscurely denticulate at the apex. 



Spikelets 2-4 mm. long; lemma broadly oval, l..'5-2 mm. long. 



Leaf-blades flat and lax; lemma slightly scarious-margined; branches of the 

 inflorescence long; emi)ty glumes obtuse. 

 Plant slender; branches of the inflorescence strongly ascending, nodding. 



1. P. nervata. 



