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6. GLYCERIA Manna Grass 



Large native grasses, mostly of wet places or aquatic. Rhizomatous with 

 stout, erect stems; blades broad and flat, sheaths closed and often strongly 

 2-edged; spikelets small, awnless, several flowered; lemmas round on the 

 back and with prominent nerves. The grains of some species are important 

 food for waterfowl. 



Gould (1968) places this genus in the Tribe Mehceae. 

 A. Spikelet linear, 10-40 mm long, nearly terete 



B. Lemmas obtuse to subacute, exceeded by palea ca. 0.5 mm 



G. bore alls 



B. Lemmas sharply acute, exceeded by the palea 1.5-2.5 mm 

 G. acutiflora 



A. Spikelet ovate, 5 mm or less long, more or less compressed 



C. Panicles contracted; pedicels mostly equal or slightly longer than 

 spikelets 



D. Panicles thick, compact G. obtusa 



D. Panicles long and slender G. melicaria 



C. Panicles open with spreading branches, lax; pedicels mostly much 



longer than spikelets 



E. Spikelets large, 3-5 mm wide; lemmas with veins conspicuous 

 but not distinctly raised G. canadensis 



E. Spikelets small, 1-2.5 mm wide; lemmas with prominent raised 

 veins 

 F. Upper glume less than 1.5 mm long; spikelets up to 4 mm 



long G. striata 



F. Upper glume 2-2.5 mm long; spikelets 4-6 mm long 



G. grandis 



1. G. borealis (Nash) Batchelder (figure 19) 



Perennial. Quiet waters and less frequently in swamps. Throughout 

 N.H.; frequent. 



2. G. acutiflora Torrey (figures 18 and 20) 



Perennial. Shores and wet places. Southeastern N.H.; rare. 



3. G. melicaria (Michx.) F. T. Hubbard 



Perennial. Wooded swamp and shores. Throughout N.H.; frequent. 



4. G. obtusa (Muhl.) Trin. (figure 21) 



Perennial. Swales, open swamps and shores. Southeastern N.H.; 

 infrequent. 



5. G. canadensis (Michx.) Trin. Rattlesnake Manna Grass 



Perennial. Swales and wet places. Throughout N.H.; common. 



Variety laxa (Scribn.) Hitchc, a taller plant with somewhat smaller 

 spikelets, occurs infrequently throughout the state. It appears to 

 intergrade with var. canadensis and may not be deserving of varietal 

 rank. (Treated by Fernald (1950) as G. laxa Scribn.) 



6. G. striata (Lam.) Hitchc. var. striata Fowl Manna Grass 



Perennial. Mostly moist open sites, less common in open woods. 

 Throughout N.H.; common. 



The more northern var. stricta (Scribn.) Fern., a shorter stiffer 

 plant with lemmas having broad scarious tips, occurs frequently on Mt. 

 Washington and has been recorded from Pittsburg. 



