HOW TO KNOW THE GRASSES 



61a. Nerves of lemmas running parallel to the tip, not meet- 

 ing at the tip; lemmas usually rather broad; awnless. 

 Fig. 95 62 



61b. Nerves of lemmas converging at the acute apex; 

 lemmas awnless or owned. Fig. 96 75 



62a. Leaf sheaths with united edges, 



62b. Leaf sheaths with free, overlapping edges 71 



63a. Spikelets linear, usually 1 cm. or more long, round in cross sec- 

 tion, on short pedicels in narrow, erect panicles 64 



63b. Spikelets ovate or oblong, flattened, 7 mm. or less long; panicles 

 with drooping or erect branches 66 



64a. Lemmas obtuse; palea scarcely longer than the lemma 65 



64b. Lemmas acute, the palea much longer than the lemma. Fig. 97. 



30 



Glyceria acutiflora Torr. 



Perennial; rhizome-bearing; plants 50 — 100 

 cm. tall; panicles slender, 15 — 36 cm. long. 

 Wet soil, swamps, or shallow water. May- 

 August. The species of Glyceria all live in 

 wet places, frequently in very shallow water. 

 Their spikelets are very fragile and break 

 up at a touch when ripe. The plants are suc- 

 culent and make good forage. 



Figure 97 



52 



