5 251 



STOCK in their more recent papers. We may willi Christ use the generic or 

 suhgeneric name of Phegoptevis for a small group of species of characteristic habit, 

 including our three European species and some others (D. hexagonoptcra (Michx.) 

 C. Chr., D. oj/a;7U7!s/s (Bak.) C. Chr.), although I do not think that it will be natural 

 to do so. The long series of s[)ecies, which I have referred to S Phegopteris in 

 niv '^ Index Filiciim", can however in no way be distinguished from Eiidryopleris 

 (Laslrea). The presence or absence of an indusium may possibly be a good 

 character of a species, but will always be difficult to use; as character of a genus 

 or grou]i it is not available. To be able to decide whether a species is exindusiate 

 or not, a close examination of the sori of the living plants from their earliest 

 stages will in many cases be necessary, by studying dried material only this is 

 impossible. In some of the species originally described as species of Phegopteris, 

 1 have found an indusium in the type specimens, in others, generally referred to 

 Lastrea, I have only rarely or never seen an indusium. 



Nor has the character: round or elongated sori, any value as character of a 

 group, not to speak of genus: the species of Leptogramma must naturally be inter- 

 calated therefore amongst the species of Eiidrgopteris. A striking example of how 

 unnatural is the separation into two genera is shown by D. ptarmica, which can 

 hardly be considered anything but a form of the well known Ggmnogramma asple- 

 nioides Sw. with round sori, which besides are furnished with a small indusium. 

 The Brazilian form of Ü. diplazioides is rather a true Phegopteris with round sori, 

 but nobody will deny that its nearest relative is the typical form of 0. diplazioides 

 with gymnogramnioid sori. Considering that Jhe few species of Leptogramma with 

 a downwards narrowing leaf are not to be distinguished in all their architecture, 

 pubescence, venation, etc. from the ordinary forms of Eiidrgopteris, it seems to me 

 very unnatural on account of this, even most variable character, to refer them 

 to a separate genus, as Unokuwooi) ' like J. Smith formerly, has done, after Met- 

 TENius had already united these species with Phegopteris. It would be far more 

 natural to place these species side by side with the other species of Eiidrgopteris, 

 which they are nearest to in the general structure of the leaf. 



Should I now try in a few words to define the whole group, I would ascribe 

 the following characters to it: 



Species Dryopteridis lamina bipinnalifida ad basin attenuata, pinnis sessilibus, 

 venis liberis, simplicibus vel raro furcatis, basalibus supra sinum marginem 

 attingentibus , soris rotundis vel raro elongatis, exindusiatis vel indusio parvo 

 instructo. 



This group, the American species of which are here reviewed, is one of the 

 most prolific in forms within the whole genus. It rivals in this respect the known 

 genera of phanerogams Hieracium, Taraxacum, Rubus, Euphrasia and others, and 

 is, like these genera, evidently at present in the most active development, which 

 is shown not only by the great number of well defined, limited groups of forms, 



' Undkhwood: Bull. Toney Club 2it, \'.W2, \>ag. (>26. 



