98 



THE FERN BULLETIN 



x marginalis in which traits of D. cristata are re-ap- 

 pearing, but cannot be said to be probable, as it is 

 doubtful if spores capable of germination are ever 

 found on plants of D. cristata x marginalis. 



An interesting feature of this hybrid is the half-ever- 

 green character of its leaves. It stands, in this respect, 

 midway between the parent species. The fertile leaves 

 last more or less into the winter, not so late as those of 

 D. marginalis, but long after those of D. cristata have 

 withered. 



D. clintoniana x marginalis was found by me in 

 Pittsford some years ago, and has since been collected 

 by others elsewhere. Its occurrence is noted in the 

 latest edition of Gray's Manual. I believe no descrip- 

 tion of it has been published, and there is not space for 

 one here, but, for the benefit of those looking for it, it 

 may be said to resemble a large much over-grown D. 

 cristata x marginalis, standing in much the same rela- 

 tion to that fern that D. clintoniana does to D. cristata. 

 Specimens of it were shown with those of other hybrid 

 ferns, by Mr. Ralph C. Benedict, at a meeting of the 

 Torrey Club in New r York last winter. 



The study of hybridity in ferns promises to solve 

 many problems presented by puzzling "finds" of col- 

 lectors, and opens up a wide field for investigation, of 

 absorbing interest. 



The numbers of known American hybrid ferns is 

 rapidly increasing. Of these the oldest and best known 

 probably is Asplcnium ebenoides Scott = Asplcn'uim 

 platyncuron x Camptosorus rhizophyllus. Several year? 

 ago, Aspleninm trichomams x Bclvisia rnta-mnraria 

 described by Ascherson and Graebner in 1896, * was 

 found for the first time in America, in Proctor, Ver- 

 mont, by G. A. Woolson. t In the genus Dryoptcris 



* Synopsis der Mitteleuroparschen Flora, i: 79; 1 896. 



t SeeR/iodora, 8: 12.:i906.^ 'Also Fern Bui 7. 16: 46; 1908. 



