96 
HISTORY OF BRITISH FERNS. 
and in lowland woods, preferring, as do most if not all the 
larger Ferns, the presence of plenty of free (not stagnant) 
water. As a cultivated plant, either for pots or rockwork, 
it is most desirable, and acquiring, as it does, considerable 
size, it may be made to produce some striking effects in 
ornamental scenery. 
Like its congeners, this was formerly, and now is by 
some, considered to be an Aspidium, 
Genus V. LASTREA, or BUCKLER PERN. 
The Lastreas are known from the other groups formerly 
included with them in Aspidium, by having their indu- 
sium, or seed-cover, roundish in outline, with a lateral 
notch, so that it becomes kidney-shaped, and is attached 
to the frond by the notched part. This group includes 
some of the largest and most common of our native species, 
and nearly all of them are remarkable for their elegance. 
Several of them retain their fronds through the winter 
in sheltered situations ; but, with one exception, they are 
not strictly evergreen, and in exposed situations are bare 
during winter. 
