444 GRAMlNACEiE. 



40, GLYCERIA. Brown.— Manna Grass. 

 (From the Greek yXvKvs, sweet ; on account of the sweet taste of the grains.) 

 Spikelets long, linear, many-flowered ; rachis jointed. Glumes 

 2, membranaceous, nearly equal, pointless. Paleae njembrana- 

 ceously herbaceous, nearly equal, awnless ; the lower one usually 

 obtuse, Y-nerved ; the upper 2-keeled. Stigmas decompound. 

 — Panicle nearly simple. 



1. G. fluitans Brown: panicle secund, slightly branched, divaricate j 

 spikelets hnear-terete, appressed, 8 — 12-flowered; flowers very obtuse. 

 Festuca jluitans Linn. 



Wet grounds. N. Eng. N. Y. and Penn. W. to Mich. June, July. %.— 

 Root creeping. Culm 3 — 5 feet higli, compressed, erect or ascending. Leaves 

 long, linear-lanceolate. Panicle 12 — 15 inches long, slender, partly concealed 

 in the upper sheath ; branches mostly simple. Common Manna-grass. 



2. G. acutifiora Torr.: panicle simple, elongated, appressed; spikelets 

 linear-terete, 4 — 12-flowered; flowers attenuated, acute, indistinctly nerved. 

 Festuca acntijiora Big. 



Overflowed meadows. N. Y. and Mass. to Del. W. to Ohio. June. %.— 

 Culm about 18 inches high. Leaves short, erect, attenuated at the point. Pan- 

 icle long and slender, somewhat nodding. Resembles the preceding, but dis- 

 tinguished by its acute flowers and nerveless paleae. 



Sharp-flowered Manna-grass. 



3. G. aquatica Smith : panicle equal^^ diffuse, much branched ; spikelets 

 linear-oblong, 5— 9-flowered ; flowers free, oblong, obtuse, prominently 7- 

 nerved. Poa aquatica Linn. 



Wet meadows. Can. to Virg. July, Aug. %.—Root creeping. Culm 3 — b 

 feet high, thick. Leaves broad-linear, a foot or more in length. Panicle very 

 large, often purplish. Reed Manna-grass. 



4. G. nervata Trin. : panicle diffuse, loo^ ; the branches slender and at 

 length pendulous ; spikelets ovate-oblong, about 5-flowered ; flowers ob- 

 tuse, conspicuously 7-nerved, Poa nervata Willd. P. striata Mich. P. 

 farvifiora Pursh. 



' Wet meadows. Can. to Flor. W. to Ohio. June. %.—Culm 3—4 feet 

 high. Leaves narrow-linear, flat, smooth ; ligule ovate. Panicle large, capillary, 

 often purplish. Nerved Manna-grass. 



5. G. elongata Trin. : panicle elongated, iracemose ; branches mostly 

 solitary, appressed; spikelets ovate, obtuse, somewhat tumid, 3 — 4-flow- 

 ered ; lower palea rather acute ; stamens 2. Poa elongata Torr. Fl. 



Swamps and wet meadows. Can. to Penn. June, July. %.—Culm 3—4 

 feeth^h, simple. Leaves long, nearly smooth ; ligule nearly wanting. Panicle 

 8 — 12 niches long, somewhat nodding. Long-panicled Manna-grass. 



G. G. Canadensis Trin. : panicle large, effuse ; branches semiverticillate, 

 at length pendulous ; spikelets broad-ovate, tumid, 5 — 8-flowered ; lower 

 palea somewhat acute, 7-nerved ; upper shorter and very obtuse ; stamens 

 2. Briza Canadensis Mich. 



Swamps. Can. N. Eng. and N. Y. July, Aug. %.—CuTm 2—3 feet high, 

 erect, terete. Leaves linear, long, roughish ; ligule obtuse, lacerate. Panicle 

 G — S inches long, the branches at length spreading. Cnnadian Manna-grass. 



