A GUIDE AND KEY TO AQUATIC PLANTS 41 



16. Leaves keeled or folded 17. 



16. Leaves flat and not keeled 19. 



17. Plants aromatic when cru.shed (fig. 10) Acorus, p. 102. 



17. Plants not aromatic 18. 



18. Flowers violet, over 3 cm. across; leaves equit- Nemastylis, p. 110. 

 ant at base; that is coming in two ranks, 

 making the base of the plant appear flat- 

 tened (fig. 11). 



18. Flower inconspicuous and hidden by overlap- Cyperus, p. 87. 

 ping scales (fig. 12). 



Figure 10. 



Figure 11. 



x/z 



Figure 12. 



