84 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



parallel, usually prominent. Usually tall aquatic or marsh perennials, 



with creeping and rooting bases or with 

 creeping rhizomes, simple culms, closed or 

 partly closed sheaths, flat blades, and open 

 or contracted panicles. Type species, Gly- 

 ceriafluitans. Name from the Greek glukeros, 

 sweet, the seed of the type species being 

 sweet. 



The species are all palatable grasses but 

 are usually of limited distribution and most 

 of them are confined to marshes or wet land. 

 Glyceria elata, tall mannagrass, is a valuable 

 component of the for- 

 age in moist woods of 

 the Northwestern 

 States. G. striata, 

 fowl mannagrass, 

 widely distributed, G. 

 grandis, American 

 mannagrass, in the 

 Northern States, and 



G. pauciflora, weak mannagrass, of the North- 

 west, are marsh species but are often grazed. 



Spikelets linear, nearly terete, usually as much as 1 

 cm long, appressed on short pedicels; panicles nar- 

 row, erect SECTION 1. EUGLYCERIA. 



Spikelets ovate or oblong, more or less compressed, 

 usually not more than 5 mm long; panicles usually 

 nodding SECTION 2. HYDROPOA. 



as; 



FIGURE 123. Distribution of 

 Puccinellia pumila. 



FIGURE 124. Puccinellia nutkaensis- 

 Panicle, X 1; floret, X 10. 

 (Macoun 66, Br. Col.) 



Section 1. Euglyceria 



Lemmas acute, much exceeded by the palea 1. G. ACUTIFLORA. 



Lemmas obtuse; palea about as long as the lemma (or longer in G. septentrionalis 

 and G. fluitans) . 



Lemmas glabrous between the slightly scabrous nerves 2. G. BOREALIS. 



Lemmas scaberulous or hirtellous between the usually distinctly scabrous 



nerves. 

 Lemmas about 3 mm long, broadly rounded at the summit. 



First glume 1.5 mm long; lemmas scaberulous 3. G. LEPTOSTACHYA. 



First glume 2 to 2.5 mm long; lemmas hirtellous 4. G. ARKANSANA. 



Lemmas 4 to 7 mm long. 



Lemmas pale or green, not tinged with purple, about 4 mm long; palea 

 usually exceeding the lemma; Eastern States. 



5. G. SEPTENTRIONALIS. 



Lemmas usually tinged with purple near the tip, 4 to 6 mm long; palea 

 rarely exceeding the lemma; Western States __ 7. G. OCCIDENTALS. 



Lemmas slightly tinged with purple near the tip, 5 to 6 mm long; palea 

 about as long as the lemma, sometimes slightly exceeding it; North- 

 eastern States 6. G. FLUITANS. 



Section 2. Hydropoa 



Lemmas with 5 prominent nerves. 



Panicle ovate or pyramidal, open 8. G. PAUCIFLORA. 



Panicle narrow, the branches ascending 9. G. ERECTA. 



Lemmas with 7 usually prominent nerves. 

 Panicle contracted, "narrow. 



Lemmas about 3 to 4 mm long; panicle oblong, dense, usually not more than 

 10 cm long 10. G. OBTUSA. 



