A GUIDE AND KEY TO AQUATIC PLANTS 



87 



11. Style swollen at base but the swollen basse not persist- 3. Fimbristylis, p. 88. 



ent on achene (fig. 10). 

 11. Style not swollen at base (tig. 11) 5. Scirpus, p. 91. 



X 20 



Figure 10 



Figure 11 



12. Achene exposed (fig. 12) 11. Scleria, p. 98. 



12. Achene enclosed in a sac (perigynium) (fig. 14) _ 12. Carex, p. 98. 



Figure 12. Figure 13. 



1. Dulichium L. C. Rich. 



D. arundinaceum (L.) Britton — This species is distributed over 

 most of our area, and seems to prefer acid situations, at least in the 

 Coastal Plain, 



2. Cyperus [Tourn.J L. 



1. Achenes lenticular, 2-sided 1. C. flavescens. 



1. Achenes triangular in x-section, 3-sided 2. 



2. Plants perennial; bases hardened, corm-like, or 3. 



stoloniferous. 

 2. Plants annual; bases not hardened or stolonif- 2. C. erythrorhizos. 

 erous. 

 3. Scales of spikelets deciduous, falling away from the 4. 

 rachilla of the spikelet. 



