280 
ASPLENIACEiE. 
Ray recommends this fern as a medicine in cases of obstruc- 
tion, and also informs us that the mucilage extracted from it, 
when applied externally, is recommended for burns when all 
other applications have failed.^ 
The roots of Asplenium marinum are black, wiry, tough, long, 
and so firmly fixed in the crevices of rock, that it cannot be 
eradicated without considerable trouble : the rhizoma is tufted, 
black, and covered with bristly scales : the fronds make their 
appearance in June and July, ripen their seed in October and 
November, and remain perfectly green throughout the year. In 
August the fronds of two seasons are equally vigorous, the 
younger ones being distinguished by their paler colour and im- 
mature fructification. 
The frond is linear and simply pinnate, the pinnae are stalked 
and serrated ; their forms are various, as will be seen by the fi- 
gures, two larger than the rest frequently appear near the apex: 
the pinnae are connected by a narrow wing running along the 
rachis, as shown at d, page 276. The lateral veins are forked 
almost immediately after leaving the midvein ; the anterior 
branch bears a long linear cluster of bright rust-coloured cap- 
sules ; this, when young, is covered by a white membranous 
involucre, of similar form, which always opens towards the 
apex of the frond. 
It is a most difficult fern to deal with in cultivation, unless 
carefully protected from exposure : it will thrive luxuriantly in 
a stove-house, with a moist heat of 70° Fahr., but dies on rock- 
work, even in the purest air, if denied the advantage of the 
sea-breeze ; this is the more remarkable, since at Newton, War- 
rington, and Killarney, as recorded in the preceding pages, it 
has voluntarily forsaken the vicinity of the sea. 
It may be here observed that the present species, together 
with Aspl. viride and Aspl. Trichomanes, form another natural 
group, distinguished by the elongate and simply pinnate frond, 
by a great uniformity in the character of the pinnae, and by a si- 
milarity in the venation, 
* Hujus usus est in obstriictionibus viscerum. Extrinsecus commendatur 
ad ambusta [extracta mucilago] ubi reliqua omnia medicamenta auxilium 
negant. — Syn. 119. 
