its fronds smooth and divided into three , branches. When 
the fronds are but partially developed this latter character¬ 
istic is very obvious ; for the three branches are seen to be 
rolled up separately at the end Qf these little wire-like stalky 
the whole supported by one which is longer and stouter. It 
is a slender and delicate plant, its height being commonly ~ 
not more than six inches, often less, thougbsometimes more, 
and its texture fragile. Hence it is at once destroyed by 
frost, and soon becomes rusty and withered by exposure to 
heat and drought. When growing in a cool, shady situation, 
however, it continues fresh and cheerful-looking from April,. 
when it usually starts into growth onwards until it is 
affected by autumnal cold. In pots, in W ” 
on sheltered shady rock-work, it is alike c 
P. Dryopteris is not an uncomr 
only in mountainous situations and the'clrier parts of damp 
woods: in England ^ mostly in the northern Scotland distn- 
! POLYPODY. 
} of this Fern is Polypodium Robertianum, 
— 5 commonly known as P. calcareum, that name 
having been much used by F.nglisb writers. Other 
applied to it are Lastrea Robertiana, I ’ 
Gymnocarpium P^-~‘ : - 
The Limestone 
__P_| _ 
shorter than the sides, the stipes about equalling the leafy 
portion in length. They are partially three-branched, but 
the lateral branches are much smaller than the central one, 
.mid attached to the stipes by a more slender racliis. The 
lower branches are pinnate, with pinnatifid pinnae; the 
upper branch pinnate, with its lower pinnae again pinnate 
ana the upper ones pinnatifid, as also is the apex of the frond 
and of the lower branches. The pinnules, or lobes, have a 
distinct midvein, with simple or slightly branched venules, 
near the termination of which, in a marginal series, the son 
are produced. 
This Fern is known from P. Dryopteris , to which it is so 
nearly related, that some botanists do not consider it dis- 
fcnct, by having its fronds less decidedly, though somewhat 
three-branched, and by having its surface covered with small 
i, Phegopteris calcarea, and 
e Limestone Polypody grows from six inches to afoot in 
