82 POACEAE 



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

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

 W yo Colo. Utah n Calif. B.C. Submont. 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 Submont. 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. 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; 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. 

 Submont. Jl-Au. 



67. P. ampla Merr. Stem 6-15 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. Submont. Je-Jl. 



66. 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. 

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

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

 or acute, unequal. Lemma obtuse or truncate, often denticulate, convex on 

 the back, but not keeled, prominently nerved, hyaline 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-nerved, obscxirely denticulate at the apex. 



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



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



inflorescence long; empty glumes obtuse. 



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



1. P. nervata. 



