CHAPTER XIV. 
THE SHIELD FERNS 
{Polysticlmm. Stn. Aspidium). 
OBUST beanty combined with delicacy of detail 
are the characteristics of this family, which is 
represented in Britain by three species, and 
is easily distinguished from others by the spiny 
character of the subdivisions, and by the covers 
of the spore-heaps, which are flatly mushroom 
shaped, being circular, and attached to the 
frond by tiny central stalks — the Buckler Ferns, it 
will be remembered, having a notch in the cover, 
which renders them kidney-shaped. Besides these characters, 
the rising fronds of the Shield Ferns, in unfolding, turn inside 
out, the last few inches hanging downwards at the back of the 
frond — a feature quite peculiar to this family, so far as Britain 
is concerned. The young fronds are also densely clothed with 
silvery-white scales when they first lift from the crown, which 
scales turn brown as the fronds mature. Two out of the 
three species are pretty generally distributed ; the third, the 
Holly Fern (P. Loncliitis) must be sought for high up in the 
mountains — it is never found below a certain level. They are 
all thorough evergreens, and on that account, coupled with 
their charming diversity of form, hold first rank as ornamental 
Ferns. Soil, rich, strong, fibrous loam, with plenty of root 
room. 
