Fig. 291: a and b, Lemna valdiviana: a, fronds and root, X 5; b, group of fronds 

 from above, X 8. c, Wolffiella floridana: c, colony of plants, X 5. d and e, Wolffiella 

 gladiata: d, typical shape and habit of growth, X 3V2; e, colony of plants in water, X 

 31/^. (a-c. Courtesy of R. K. Godfrey; d and e, from Daubs). 



