EEV. M. J. P.EEKELEY ON A SUPPOSED HYP-KID FEKtf. 



137 



XXV. On a supposed Hybrid Fern from Philadelphia. 

 By the Eev. M. J. Beekeley, M.A., F.L.S. 



I eeceiyed a short time since a letter from Mr. E. Robinson 

 Scott, of Port Kennedy, Philadelphia, enclosing a specimen ac- 

 companied by a nature-printed impression of an extremely inter- 

 esting fern, which is the subject of the present communication. 

 The letter commences as follows : — 



" I take the liberty of enclosing a frond of an Asplenium found 

 by me three years ago in this vicinity, eight miles from Philadel- 

 phia on the banks of the Schuylkill, growing on limestone rocks 

 in a very rocky place. It was surrounded by Camptosorus rJiizo- 

 phyllus and Asplenium ebeneum. It has the characteristics of both 

 these ferns in part. It is, as you will see, distinct from any of 

 the species in Gray's ' Manual of the Northern United States.' 

 Dr. Gray, after three years, admits it to be a new species ; and as 

 I had called it ebenoides, he agrees to adopt that name. It may 

 not appear new to you." A single plant only was found, which is 

 still alive ; and I believe no other has since occurred. 



I immediately transmitted the specimen to Sir W. J. Hooker 

 for verification, who pronounced it entirely new to him, and the 

 most probable instance he had yet met with of a real hybrid 

 amongst ferns. 



The species seems to combine exactly the characters of the two 

 with which it was found in company. Camptosorus is distinguished 

 from Asplenium by the simple frond, reticulated veins, and the 

 sori being often approximate in pairs by their free margins, or at 

 their apices, so as to form curved lines, whence the name is 

 derived. Now in Asplenium ebenoides the veins do not anasto- 

 mose at all, but are just like those of Asplenium ; but occasionally 

 the sori are approximate, and the free edge of the indusium is in 

 different directions, as in Camptosorus. They are occasionally 

 scolopendroid, though more frequently diplazioid # . If we exa- 

 mine the frond we find that, while the pinnse are obscurely crenate 

 instead of being finely serrate, they are frequently much more elon- 

 gated and far less auricled at the base than in A. ebeneum, and, in 

 fact, have some of the character which appears occasionally in the 

 auricles of Camptosorus ; besides which, the apex of the frond is in- 

 clined to be caudate, and, above all, both this and the more elon- 

 gated pinnae are viviparous, a character which it has in common 



* A similar diversity in the direction of the sori takes place in Lomaria pane- 

 tulata (Scolopendrium Krebsii, Kze.). 



