A GUIDE AND KEY TO AQUATIC PLANTS 



25 



5. Leaves alternate, not prominently toothed, subcordate Breweria, p. 134. 



at the base (fig. 5). 

 5. Leaves opposite, with wavy margins or angularly Mikania, p. 139. 



toothed (fig. 6). 



X /o /: 



Figure 5. 



Figure 6. 



KEY TO GROUP C 



1. Plants very small ; seldom over a centimeter along any 2. 



dimension, 

 1. Plants large; usually measuring at least 0.5 decimeter 8. 

 along some dimension. 

 2. Plant body dichotomously 2-lobed, or repeatedly 3. 



dichotomously branched. 

 2. Plant body not dichotomously branched and if 2- 4. 

 lobed not equally so. 

 3. Divisions of plant body fine and many; plant body Riccia, p. 67. 



usually floating below surface (fig. ]). 

 3. Divisions of plant body coarse, 2-lobed; floating on Ricciocarpus, p. 67. 

 surface (fig. 2). 



xl7: 



Figure 1. 



Figure 2. 



