174 
BRITISH FERNS. 
from erect to horizontal, arched, or pendulous. The 
stem continues in a strong midrib, with transverse veins, 
each branched twice, but the branches running in the 
same transverse direction. To the outermost branches 
of each group of veins a long narrow sorus is attached, 
which, meeting the sorus attached to the answering 
branch of the next group, the pair lie so near together 
that they look like one, until at last the two involucres 
roll back and show the two ridges of seed. 
This is a remarkably handsome fern, its simple form 
and shining verdure making it a charming contrast to the 
pale feathery fronds of the Lady-fern and Shield-ferns. 
The young fronds appear in April, at first rolled in, then 
gradually assuming an erect position, from which they 
soon diverge into every variety of graceful arch. Seed- 
ling plants take many curious forms, being sometimes of 
a pointed oval figure, sometimes heart-shaped, sometimes 
blunt and elongated. A group of HartVtongue has 
always a charming effect in the landscape, whether its 
fronds droop from the grey rocks in the thickets of 
North Yorkshire, or from the steep red banks of shady 
Devonshire lanes. It also establishes itself in the crum- 
bling walls of old ruins, in which position it is certainly 
not less interesting than in its native wilds. 
Scolopendrium vulgare , var. crispum , has the leafy 
part of the frond very luxuriantly developed, so that the 
margin is frilled like a lady^s ruffle. This variety is 
much valued in ferneries, where it forms a pleasing object. 
Var. marginatum has narrow fronds, the margin 
notched into uneven lobes, which bear sori as well as 
the frond ; it has a starved appearance, but is valued in 
ferneries as a rare form. 
Var. multifidum has the fronds forked, often several 
