132 
European Ferns. 
uppermost venule of one vein is so close to the innermost one of its neighbour that the two 
indusia which are attached to the upper and lower sides of the venules respectively at first 
touch, and seem united into one. After a little time a line is seen between them, showing 
that the sori are really distinct ; and at length the indusia are completely pushed back in 
opposite directions, and covered with the masses of brown sporangia. When the fronds are 
first unrolled, the sori appear only as slight greenish-white swellings, but they rapidly develope ; 
their form has suggested the not inappropriate name of “ Buttonholes,” by which the plant is 
known in some parts of Sussex. 
The stipes of the Hart’s-tongue is short, one or two inches in length, of a dark colour 
below, which extends some way along the back of the rachis, and covered, especially at the 
base, with long, light-brown hairs or scales, which are very easily rubbed off. These hairs 
often extend in young plants along the whole of the rachis to the very apex ; the fronds are 
sometimes hairy, at other times quite smooth, the older specimens being usually destitute of 
hairs. The mature fronds do not wither 
until those of the ensuing year are ex- 
panded, although in their darker hue and 
the withering of their tips they give indi- 
cations of approaching decay. The fronds 
even when young have a curiously waved 
appearance, somewhat resembling that of 
some of the seaweeds belonging to the 
genus Laminaria ; and this peculiarity 
has gained for the plant in some places the 
name of the “ Seaweed Fern.” In their 
seedling state the fronds are of a thin, 
almost transparent, texture, and waved 
at the margins ; the accompanying figures 
show the plant in one or two of its 
earlier stages. 
As we have already remarked, the Hart’s-tongue is widely distributed in England ; it is, 
indeed, recorded for all the counties, except those — principally Welsh — the flora of which is 
imperfectly known. In Scotland it is, perhaps, less frequent; while in Ireland it is very 
common. Its relative abundance in various districts is, however, very different ; in many 
localities, although not altogether unknown, it is quite a rare plant ; while in others we 
meet with it at every turn, and come to consider it as one of the commonest of plants. 
This is notably the case in some parts of the Isle of Wight, where it grows in the 
greatest luxuriance and profusion ; the long glossy fronds hanging down from the hedge- 
banks, and in places completely covering them. On old walls it sometimes attains a good 
size, especially in damp localities ; but it is usually a small and inconspicuous plant under 
such circumstances. It is somewhat remarkable as possessing a few genuine English names, 
an occurrence, as we have before observed, somewhat rare among ferns ; one or two of these 
we have already named. In the county of Westmeath it is known as “ Burntweed,” on 
account of its being employed there as a remedy for burns ; in the island of Guernsey it 
is called by the singular name of “Christ’s Ilair,” the allusion being to the single, black 
fibrovascular bundle in the stipes. In some parts of Hampshire it has the very suitable 
name of “ Longleaf,” and it was the shape of the leaf that suggested the old Latin name, 
