124 
European Ferns. 
ATHYRIUM CRENATUM, Ruprecht. 
This elegant fern resembles a Cystopteris rather than an Atliyriuin in habit, and has, 
indeed, been referred to the former genus, although it is properly an Athyrium. It differs 
from the Lady Fern in the shape of the fronds, which is triangular or deltoid, not 
lanceolate. A. crenatum has a creep- 
ing caudex, about as thick as one’s 
finger, from which rise the erect stipites 
alternately at somewhat irregular inter- 
vals ; these are from six inches to a 
foot in length, of a pale or tawny- 
brown hue, darker at the base, and 
clothed in its lower part with large 
brown pointed scales, the upper portion 
being smooth. The leafy portion of the 
frond is about equal to the stipes in 
length and of nearly the same breadth ; 
it is membranous in texture, and three 
or four times pinnate with from seven 
to twelve pinnae (of which the lowest 
are much the largest) on each side; 
the pinnules are narrow, and divided to 
the rachis into a few blunt segments. 
The fronds are somewhat hairy, though 
sometimes very slightly so, both below 
and above ; the sori are small, fewer in 
number than in the Lady Fern, and 
either straight or curved — a variability 
which explains how it is that the plant 
has been placed in different genera by 
different authors ; the indusium is pale- 
brown, and ciliate at the margin. 
This is a fern of small geogra- 
phical range. It occurs in various parts 
of Sweden, Norway, and Lapland, at 
athyrium crenatum. altitudes of from six hundred to a 
thousand feet above the sea, and also 
in Amur-land, Dahuria, and Kamtschatka ; it is also on record from Japan. It is a very 
pretty plant, of a beautiful light-green colour, and very distinct from its congener the Lady 
Fern in the triangular shape of the fronds; as we have already said, it resembles a 
Cystopteris in appearance, or, perhaps even more closely, the seedling form of the Bracken. 
