Fig. 130. Morphology of the three European species of Polypodium from Hving leaves grown under 

 comparable conditions, half natural size. a. The diploid (var. serratum), the left-hand leaf from 

 Cheddar (Somerset), the right-hand leaf from the south of France, b. A leaf from the same plant 

 as the right-hand specimen of a to show forwardly projecting lower pinnae, c. The normal form 

 of tetraploid Polypodium in Britain; note the narrow frond, d. A large and a small frond from the 

 hexaploid in Britain. 



131 9-2 



