
' 92 THE BRITISH FERNS. 











pinnate. Pinne oblong oblong-ovate or linear, oblique, the anterior 
basal angle being most produced, obtuse, often nearly equal in width 
throughout, usually about an inch in length; the anterior base 
truncately rounded, and forming a blunt more or less apparent 
auricle, the inferior base eut away obliquely in à wedge-shaped 
manner. The lowest pinne are stalked, with the stalks winged ; 
but the upper ones become decurrent, and at length confluent into a 
tapering pinnatifid apex. The margins are doubly crenato-serrate, 
the serratures unequal, sometimes deeper forming evident lobes. 
Venation consisting of a prominent flexuous costa or midvein from 
which branch out the forked veins; the lowest anterior vein is two or 
three times forked, while the rest are usually once forked only; the 
venules terminate abruptly within the margin, the anterior ones 
generally bearing the sori. 
Fructification spread over the back of the frond. Sori linear, 
oblique, indusiate, borne on the anterior side of the venules (except 
sometimes on those of the auricle, when two or more sori are borne 
by the same fascicle of veins), commencing on each side near the 
costa, and forming two series of short divergent lines along each 
pinna. The sori, though consisting of a profusion of spore-cases, are 
commonly distinct, though they sometimes coalesce so as to cover 
the whole under surface. Indusium of the same form, persistent, 
entire. Spore-cases numerous, globose, brown. Spores ovate, 
angular. 
Duration. The caudex is perennial. The fronds being persistent, 
and the young ones each year produced long before the s ones 
decay, the species 1s truly evergreen. 
This is a well marked species, distinguished from the other simply 
pinnate British Aspleniums by its winged rachis, and by its greater 
size and more coriaceous texture. This latter feature gives to it an 
aspect of massiveness as compared with its size, by which it may be 
‚known at first sight. 
This plant occurs in clefts and caves of rocks, and often abun- 
dantly, on all our coasts, with the exception of those of the eastern 
.side of England, and is essentially a maritime species. It is most 

