THE FERN BULLETIN 



Vol. XX JULY, 1912 No. 3 



POLYPODIUM OR XIPHIOPTERIS? 



By Willard N. Clute. 

 There are times when one has almost a shade of 

 sympathy for those who tinker with generic names. 

 When one gets the characters of a genus well in mind 

 and then in further studies finds specimens referred to 

 that genns which apparently have none of the ear- 

 marks of the group he is tempted to think that there 

 might possibly be cases where a change of name would 

 be beneficial. Nor is it the distant and obscure genera 

 that fall into this category. As common and familiar 

 a genus as Polypodiiun has a lot of poor relations or 

 second cousins connected with it, and these are often 

 grouped with more representative species though they 

 may look so little like typical members that it is not 

 easy to see the relationship. If there is one thing that 

 the beginning fern student comes to feel sure of, it is 

 his ability to identify the Polybodiums by means of 

 their rounded fruit dots lacking an indusium. This 

 holds good, it is true, for all ordinary occasions, but 

 taking the group as a whole, there are many exceptions 

 to it. Recently a polypody was shown in this maga- 

 zine in which the sori were apparently linear like 

 those of Asplenium and we have chosen for illustration 

 this time another species quite unlike the conventional 

 polypody. 



Polypodium serrulatum, whose likeness is presented 

 in the frontispiece is not only unlike a polypody but 

 unlike most other ferns as well. Its small stature and 

 slender leaves suggest a fleeting resemblance to the lit- 



