13 



5^0 



Q Q 



Q 



X^ ^>' - Oo^ -^^ 



B 



D 



Figure 5. 

 Wolffia Columbiana: A. habit and floating view x 5. 

 Wolffia borealis: B. habit and floating view x 5. 

 Wolffia brasiliensis: C. habit and floating view x 5, 

 Wolffiella gladiata: D. floating view x 4, 

 Spirodela polyrhiza: E. habit x 4. 



