MANUAL OF THE GRASSES OP THE UNITED STATES 



85 



Figure 126.— Distribution of 

 Glyceria acutiflora. 



Lemmas 2 to 2.5 mm long; panicle rather loose, nodding, 15 to 25 cm 



long 11. G. MELICARIA. 



Panicle open, lax. 



Nerves of lemma evident but not prominent 12. G. canadensis. 



Nerves of lemma prominent. 

 Culms decumbent, weak. 



Blades 4 to 8 mm wide; anthers 1 mm long 17. G. pallida. 



Blades 1 to 3 mm wide; anthers 0.2 to 0.5 mm long__ 18. G. neogaea. 

 Culms erect, usually stout. 

 First glume 1 mm long or less. 



Blades 2 to 4 mm wide, sometimes to 8 mm, rather firm, often folded; 



first glume 0.5 mm long 13. G. striata. 



Blades 6 to 12 mm wide, flat, thin, lax; first glume about 1 mm long. 

 Lemma narrowed into a hyaline tip with no colored border. 



14. G. ELATA. 

 Lemma broad at summit with a purple zone just below. 



15. G. otisii. 

 First glume 1.5 mm long. Panicle large, compound.. 16. G. grandis. 



Section 1. Etjglyceria Griseb. 



Spikelets linear, nearly terete, usually more than 1 cm long, appressed 

 on short pedicels; panicles narrow, erect, the branches appressed 

 or ascending after anthesis. The species 

 of Euglyceria, with the exception of Gly- 

 ceria acutiflora, are very closely allied and 

 appear to intergrade. 



1. Glyceria acutiflora 

 Torr. (Fig. 125.) 

 Culms compressed, lax, 

 creeping and rooting 

 below, 50 to 100 cm long; 

 blades flat, lax, 10 to 15 cm 

 long, 3 to 6 mm wide, sca- 

 brous on the upper surface; 

 panicle 15 to 35 cm long, often 

 partly included, the branches 

 rather stiff, bearing 1 or 2 

 spikelets, or the lower 3 or 

 more; spikelets 5- to 12-flow- 

 ered, 2 to 4 cm long, 1 to 2 mm 

 wide, the lateral pedicels 1 to 3 

 mm long ; glumes about 2 and 

 5 mm long; lemmas 7-nerved, 

 acute, scabrous, 6 to 8 mm 

 long, exceeded by the acumi- 

 nate, 2-toothed paleas. Ql 

 (Panicularia acutiflora 

 Kuntze.) — Wet soil and shal- 

 low water, New Hampshire to 

 Delaware, west to Michigan 

 and Tennessee (fig. 126); also 

 northeastern Asia. 



2. Glyceria borealis (Nash) 



Batchelder. Northern 



MANNAGRASS. (Fig. 127.) 



Culms erect or decumbent at 

 base, slender, 60 to 100 cm 

 folded, usually 2 to 4 mm wide, 



Figure 125.— Glyceria acutiflora 

 Panicle, X 1; floret, X 10 

 (Knowlton 866, Mass.) 



tall; blades flat or 



Figure 127.— Glyceria 

 borealis. Panicle, X 

 1: floret, X 10. 

 (Fernald 193,Maine.) 



sometimes 



