New ferns described as hybrids in the genus Dryopteris 



Philip Dowell 



During the past five years I have been interested in the study 

 of our native ferns in the field ; and in our woodland swamps on 

 Staten Island, and elsewhere in the vicinity of New York, I have 

 occasionally met with forms that are not referable to any one 

 recognized species but have characteristics in common with two 

 known species. I do not refer to sports or mutants, which I have 

 found also, and which can usually be referred definitely to some 

 one species. The most plausible explanation in the case of these 

 ferns is that they are hybrids, or that they have at least originated 

 as hybrids between the two species whose characteristics they share, 

 and as such they are here described in accordance with our Ameri- 

 can code. At all events they are new and deserve to be described 

 and named. It should be borne in mind that these ferns grow m 

 moist woodlands or in swampy places, where the conditions are 

 favorable for the mingling of the gametes, and that natura hybnds 

 may thus be easily produced. This was mentioned in 7^ ^ 0. 

 208, i 9 o6, in an article entitled « Observations on the Occurence 

 of Boott's Fern/' although at that time I was rather skeptical about 

 hybrids among ferns. That hybrids do occur among fern has 

 been experimentally proved by Miss Margaret S bsson and oth r , 

 By selecting and manipulating the P"^^^^ 

 and archegonia, Miss Slosson produced * ^™ ^* 

 tens cristata and D. marginal* which l°oks^ same a 

 hybrid described by G. E. Davenport as D^ *** X ^ 

 Miss Slosson produced also, in a -**~%£ % icum - Carl 

 ling Asplemum ebenouies Scott. In ofwh ich he includes 



Christensen recognizes a number of hybrids 

 three or fonr in the ^enus Dryopteris, four if we maun r 



A 



/hich ne is nut •«••— i - 

 ybmlosa, as suggested by 'Miss 



marginal* x sjnnulosa, as sugg»«~ / ex Filicumare 



described it The other three ^recognized m ^.^ 



D. Filix-mas x spinulosa (A. Br.) C. Chr., v. 



135 



