On Stigmatopteris^ a new genus of ferns 

 with a review of its species. 



By 

 Carl Christensen. 



The vast genus Dryopteris, which includes, as confined in 

 my "Index Fihcum", almost 1000 species, is together with the still 

 larger genus Folypodium, the crux of all pteridologists. But while 

 Polypodium can easily be divided into partly well limited subgenera, 

 the majority of which I now consider good genera, the numerous 

 species of Dryopteris seem to show only a slight variation as to 

 the generic characters generally accepted. In my "Index Filicum" 

 the genus was, it is true, divided in several subgenera, but at least 

 two of these, Phegopteris and Leptogramma cannot be upheld, if 

 we by the term "subgenus" are to understand an aggregation of 

 really related species. 



The proposed groups of the species of Dryopteris are more or 

 less unnatural, as they, as a rule, are based on a single character. 

 As far as I have seen by studying the American species of the 

 genus, no single character is sufficient as base of such a grouping. 

 Whether one or another character is chosen as base it is quickly 

 found that it will be necessary to unite into the same group species 

 of evidently remote alliance and vice versa, I have myself com- 

 mitted the same error in my revision of the American species of 

 Dryopteris of the group of D. opposita ^), in using the character 

 '^lamina decrescens" as an absolute mark of the group. To the 

 group of D. opposita some few other species [D. caespitosa and 

 others) must be referred, although they have not a decrescent 

 lamina, and a species as D. Thomsonii (syn. D. Stilhelii) is a near 

 ally of D. decussata, the type of another group, Glaphyropteris. 



1) Vid. Selsk. Skr. VII. 4. 190G. 



