European Ferns. 
i 66 
constant in cultivation. Mr. Moore enumerates and describes sixteen varieties in all, in- 
cluding a pretty plant having the points of all the segments crisped and tasselled, known as 
cristatum. 
THE OAK FERN: POLYPODIUM DRYOPTERIS, L. 
Although P. Dryopteris is so generally known, both in books and in ordinary conversation, 
as the Oak Fern, this title, as we have already said, belongs of right to the species last 
described. The present is one of our most delicate and 
beautiful ferns, attracting attention at once by its graceful 
light-green fronds. In the south of England it is rare, 
North Devon and East Cornwall being the only counties 
in which it is found south of Gloucestershire. In the 
centre and north of England it is widely distributed, as 
also in Scotland. In Ireland it is very rare, its only 
certain stations being on Benbo mountain, in co. Leitrim, 
at an elevation of eight hundred feet, and sparingly on 
Knochlayd mountain, co. Antrim, at the height of about 
eighteen hundred feet ; other recorded Irish localities 
require confirmation. It is widely distributed through 
Europe, from the extreme north to Italy, Spain, and 
Gibraltar ; in Asia it has been found in Siberia and 
Kamtschatka, the Himalayas, and quite lately in the 
Kuram Valley, Afghanistan ; and it is reported from 
Africa, although we do not know from what region. In 
America it is widely spread, occurring in Arctic Greenland 
and Labrador, Sitka, the Rocky Mountains, the United 
States, and Newfoundland. 
From the slender-branched perennial caudex of the 
Oak Fern arise three-branched fronds from four to twelve 
inches, or even more, in height, and about half as broad 
proportionately, including the stipes. In vernation the 
fronds present a curious appearance, each branch forming 
a compact little ball, apparently supported on green wire ; 
when the fronds unfold they are of a pale, but very 
exquisite green, and this hue is perhaps the greatest charm of the plant. Being of but annual 
duration the fronds die down completely in the winter, leaving a gap upon the rockwork 
which does not altogether satisfy the cultivator. The branches of the frond are pinnate or 
sub-pinnate, the pinnae on the lower side of the two lateral branches being larger than the 
rest : the pinnules are blunt and wavy. The fructification consists of numerous small sori 
scattered all over the surface of the back of the fronds. 
To appreciate the beauty of the Oak Fern it is necessary to see it growing in profusion 
among the rocks and stones of the lake district, or in the mountains of North Wales, where 
its bright, delicate hue lightens up the stony masses in a charming manner. Unfortunately 
it withers very readily, so that unless seen in a growing state it is difficult to form any idea 
of its extreme elegance. It is not a difficult fern to grow, succeeding well in a mixture of 
