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BRITISH FERNS. 
its genus, but it lias been frequently confused with the 
Lady-fern, which it resembles in form and habit. It is 
distinguished by its naked 
seed-masses. 
The Polypodium alpestre 
was first discovered in Eng- 
land by Mr. H. C. Watson. 
He found it in Forfarshire and 
Inverness-shire in 1841, and 
it has since been discovered 
elsewhere in the alpine parts 
of Scotland. It is found in 
Norway, Lapland, Russia, Ger- 
many, and N.W. America. 
In cultivation, the place for 
it should be excavated, and 
freely drained by means of a 
thick layer of porous stone 
and broken crocks ; it should 
then be planted in the usual compost of peat-earth, leaf- 
mould, and silver-sand, receiving a good supply of water 
in the early summer. Such is Mr. Johnson’s mode of 
treating the fern. 
A well-marked variety, with shorter pinnae, is known 
as Poly podium alpestre, var. flexile ; its texture is ex- 
tremely tender, its texture is extremely narrow, and not 
only are its pinnae shorter but considerably fewer in 
number, they extend further down the stem than in the 
normal form, and are comparatively distant ; the pin- 
nules are toothed. It is found in the Clova moun- 
tains. 
Poly podium alpestre, var. tripinnatum . Varies from 
the normal form in an opposite degree. Its fronds are 
