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 PERW. 



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. 



