

104 THE BRITISH FERNS. 
the rachis by the lower angle, usually somewhat crenated but some- 
times nearly entire on the margin, and always entire at the cuneate 
base. Sometimes most of the pinne, and usually the lower ones, 
are more ovate in outline and less unequal-sided ; more rarely the 
reduction of the upper basal angle gives the pinne an obovate out- 
line. The pinne are readily detached from the mature fronds, and 
eventually fall away, leaving the rachis bare. 
Venation consisting of a midvein, from which issue forked veins, 
terminating within the margin; of the venules or branches the ante- 
rior one of each fascicle bears the sorus above the point of furcation. 
Fructification generally distributed over the frond. Sori linear, 
oblique, numerous, often in age becoming confluent, indusiate. In- 
dusium entire or slightly erenated on the free margin. ‚Spore-cases 
numerous, globose. Spores angular, rough. 
Duration. The caudex is perennial. The fronds are persistent, 
so that the plant is evergreen ; the young fronds make their appear- 
ance in the spring months, about May. 
This species has much general resemblance to Asplenium viride, but 
differs in various features. Thus, it may be known by its dark brown 
bluntly keeled rachides, with their thin raised anterior borders; and 
further by the attachment of the pinne, which are deciduous in this, 
“but persistent in viride. It does not resemble any other native 
species. It is one of the most elegant of the smaller evergreen 
hardy kinds. 
This species is generally distributed throughout the United King- 
dom and Ireland, and is usually found growing on rocks, walls, and 
ruins; more rarely in hedgerow banks, where, however, it attains 
greater luxuriance. It is rare in the eastern counties of England, 
more abundant westward; and is found reaching an elevation of 
upwards of 2000 feet above the sea. Specimens from the west of 
Ireland, communicated by Mr. W. Andrews, and from Galway, by 
Mr. R. Barrington, are upwards of a foot in length, and furnished 
with about thirty pairs of pinne which are about half an inch long 
and a quarter inch broad; these large forms seem to have been in 
some instances incorrectly referred to the Asplenium anceps. The 

