112 
BRITISH FERNS. 
verdure, to the crumbling wall a fresh grace of contour, 
it adds charm to both, while its continued greenness 
makes it doubly acceptable in winter, when most of its 
compeers have yielded to decay. The chestnut scaliness 
of its quaint caudices forms as pleasing a contrast to the 
prevailing green of the summer woods, as the verdure of 
the fronds does to the iron grey of winter; and thus the 
“Polypody of the Oak” is beloved at all seasons. 
This is a fern belonging to temperate climates ; it is 
unknown in the tropics, but frequents North America, 
Canada, and the Cape of Good Hope, 
There are interesting varieties of this fern, which are 
much valued *in ferneries. 
1. Poly podium vulgar e Cambricum , or Welsh Polypody . 
Here the frond is broad, and the pinnae toothed. Ray 
first mentions this fern ; he has it from Powis Castle, in 
Glamorganshire. 
2. Polypodium vulgare bifidum , or Forked Polypody . 
In this variety each pinna is forked at the point ; it has 
been found in Yorkshire and Monmouthshire. 
3. Poly podium vulgare acutum. The point of each 
segment tapering ; a scarce variety. 
4. Polypodium vulgare omnilacerum . All the pinnae 
cut into sharp teeth, and divided halfway to the midrib ; 
a variety of the Cambrian group. 
5. Poly podium vulgare semilacerum. The pinnae of 
usual length, but only divided on the lower part of the 
frond, where the segments are very deeply cut. 
6. Polypodium vulgare aurito-dentatum. A small- 
fronded variety, each pinna furnished with an ear, and 
dentate at the margin. 
7. Polypodium vulgare auritum. Smaller still in its 
habit of growth, eared like the last, and many of the 
pinnae forked. 
