a s p l e n iu m . 67
known from all other indigenous Eerns, excepting the Ceterach,
which latter is readily distinguished from them by
having the back of its fronds coated with brown scales,
among which the sori are hidden. They are the types of
the tribe Aspleniece, which consists of Eerns having the
elongate masses of fructification attached along the side of
the veins, and covered by an indusium of the same elongated
form as the sori themselves. The Aspleniums are known
from their nearest allies, the Athyriums, by the latter having
the free margin of the indusium fringed with capillary or
hair-hke segments, while the margin of the indusium of As-
pleiiium is either quite entire or very slightly jagged. There
are nine species of Asplenium indigenous to Britain, and all
of them are interesting to the cultivators of Eerns,
The word Asplenium comes from the Greek asplenon ; a
name applied by old authors to some kind of Eern possessed
of supposed virtues in curing diseases of the spleen.
A s p l e n iu m A d ia n tu m -n ig r u m , Linnoeus.— The Black
Spleenwort. (Plate X II. fig. 2.)
Tins is a rather common evergreen Eern, and a very conspicuous
ornament of the situations where it occurs in a
vigorous state. The fronds grow in tufts, and vary much
in size, from a height of three or four inches when it occurs
on walls, to a foot and a half and even two feet including
the stipes, when it occurs on shady hedge-hanks in congenial
soil. The fronds are triangular, more or less elongated
at the point, the shining dark purple stipes being
often as long as, or longer than, the leafy portion, but in
stunted plants growing in sterile situations very much
shorter; they grow erect or drooping, according to the
situations in which they occur. They are bipinnate, or sometimes
tripinnate ; the pinnæ pinnate, triangular-ovate, drawn
out at the point, the lower pair always longer than the next
above them. The pinnules, especially those on the larger
pinnæ, are again pinnate; the alternate pinnules being
deeply lobed, and the margins sharply serrate.
The fronds are of a thick leathery texture, with numerous
veins. To each pinnule there is a distinct midvein or principal
vein, bearing simple or branched venules, on which
the sori are produced. All the ultimate divisions of the
fronds, as well as all the larger lobes, have midveins producing
these simple or branched venules, and these bear the
sori near their junction with the midvein, so that the sori
are placed near the centre of every pinnule or lobe. At
first the sori are distinct, and have the elongate narrow
form common to this genus, but as they become older they