ON THE GENERA OF FERNS: A STUDY OF THE 

 TRIBE. ASPIDIE/E. 



By B? D. Gilbert. 



AFTER a short introduction, in which the speaker referred to 

 the many specific. changes in nomenclature that have taken 

 place in recent years, he said : 

 While all this revision in the species of ferns is going on, it 

 has occurred to me that some change in the genera of ferns might 

 very properly be made in the interest of a more rational and nat- 

 ural arrangement of that family of plants. One generic change 

 has already been made, viz. , the adoption of Dryopteris in place 

 of Aspidium and Nephrodhim ; but this seems rather to compli- 

 cate than to simplify the situation. As I intend to confine my 

 observations at the present time to the tribe Aspidiece, let me 

 explain what I mean by this assertion. 



The tribe Aspidiece has always been a bothersome one for 

 systematists to handle. It stands on the border-land between the 

 indusiate and the non-indusiate ferns, and hence contains char- 

 acteristics belonging to both. The natural affinities between the 

 ferns placed in this tribe and those of the sub-genera Phegopteris 

 and Goniopteris (according to Hooker), which were formerly 

 placed in the tribe Polypodiece through absence of an involucre, 

 were so strong that it was actually impossible to say where one 

 ended and the other began. Numerous instances could be cited 

 from Hooker's " Species Filicum" to illustrate this fact. For in- 

 stance, under Nephr odium oligocarpum Hooker says: 44 So 

 difficult is it to see an involucre, that, but for Mettenius having 

 so accurately described it, I should have preferred to retain it in 

 Polypodium {Phegopteris)." Again under Nephr odium piloso- 

 hispidum he says: " The involucres are so minute that I feel 

 doubtful whether they really exist." These are only examples 

 of remarks that occur quite frequently. Then it is well 

 known that a creeping fern of the West Indies has been 

 placed by some authors in Polypodium as P. {Goniopteris) 

 reptans, and by others in Nephrodium, as N. reptans. 

 In the same way Mettenius named a plant Aspidium scolo- 

 pendrioides, and Hooker in "Species Filicum" followed him, 

 saying: "It is true our own specimens show no trace of involu- 

 cres, but Mettenius describes them, and there is no question of his 



