266 FORKED SPLEENWORT. 



matter of difficulty and doubt. We find our earliest authors 

 properly referring this plant to the ferns. Eay calls it " Filix 

 saxatilis Tragi" (Syn. 120), and Linneus (Sp. Plant. 1524), fol- 

 lowed by Hudson, Bolton, Berkenhout, Withering, and several 

 others, denominates it Acrostichum septentrionale, but Wither- 

 ing observes, that when young it is an Asplenium. Roth re- 

 moves this species, together with Amesium germanicum and A. 

 Euta-muraria, to the genus Scolopendrium, which also includes 

 Phyllitis Scolopendrium and Notolepeum Ceterach of the pre- 

 sent work. Euta-mtu-aria, germanicum and septentrionale form 

 a group very distinct from the other British species of Asple- 

 nium, inasmuch as their pinnules want the midvein, which is 

 always present in the rest. 



L 



Amesium septentrionale occurs most abundantly in Hungary, 

 some parts of Germany, and the South of France : it is also 

 recorded as an inhabitant of Lapland, Sweden, Denmark, Eus- 

 sia (both Asiatic and European), Spain, and Italy. In the 

 North, it seems very rare ; in the South, much more common. 

 I believe it has not yet been observed in America. 



This is one of the rarest of our British ferns : it occurs only 

 in the fissures of rocks, and the interstices of stone walls ; in 

 the latter situation it appears to thrive more luxuriantly, pro- 

 bably from the frequently exposed jjosition and elevation of the 

 former. I think I have seen specimens from nearly all the 

 recorded stations, and none of them are equal in luxuriance to 

 those which I found by the farm-yard at Llanrwst, which, being 

 on the Conway, and not far from its mouth, is but slightly ele- 

 vated above the level of the sea. At Llanrwst, the tufts of this 

 fern were very large ; one of them was so heavy, that after 

 shaking out all the loose earth, I found it a very inconvenient 

 load to carry for even the single mile I had to convey it : this 

 tuft, consisting I suppose of a single caudex, had upwards of 

 three hundred perfectly vigorous fronds, besides at least an 

 equal number of decaying ones, the relics of previous years. 



In occurs in twelve counties, — four Scotch, six English, and 

 two Welch. I have no record of its occurrence in Ireland. 



