82 



POACEAE 



obtuse, nearly 4 mm. long, puberulent, somewhat villous towards the base. P. 

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

 Wyo. — Colo. — -Utah — n Calif. — B.C. Suhmont. — Moni, 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 — Suhmont, 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.Submont. 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. higli, stiff; leaf-blades 1-2 dm, 



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



spikelets 3-5-flowTred, 7-9 mm. long; empty 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, 

 Suhmont. Jl-Au. 



67. P. ampla Merr. Stem f>-15 dm. high; leaf-blades flat, somewhat 

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

 long; spikelets 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. Suhmont. J^JL 



65. SCOLOCHLOA Link. 



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

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

 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. 

 Oram hairj- 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 oi)en, 2-3 

 dm. long; spikelets 6-8 mm. long; empty 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 rootstocks (all ours), rarely annuals. Inflorescence 

 paniculate, hpikelets usually numerous, ovate to linear, few-many-flowered, 

 the glabrous rachilla articulate between the flowers. Empty glumes 2, obtuse 

 ?u ^/^^^^^' "^i^n^^al. Lemma obtuse or truncate, often denticulate, convex on 

 the back, but not keeled, prominontly nerved, hyaline at the apex. Pulct 2-kccled. 

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



Spikelets ovate or oblong, 6 mm. long or less 



Lemma 7-nerved, obscurely denticulate at the apex. 



Spikelets 2-4 mm long; lemma broadly oval, 1.5-2 mm. long. 



l-eat-blartes flat and lax; lemma slightly scarious-margined; branches of the 



inflorescence long; empty glumes obtuse. 

 ii'iant slender; branches of the inflorescence strongly ascending, nodding- 



1. P, nertata. 



