Polypodium. 
165 
will work you up and down, and it is the best physic that grows ! ” It seems to have been 
formerly imported into Ireland; Threlkeld, writing in 1727, says: “The roots are used for 
purging in antiscorbutick diet-drinks ; Ireland is so miserably bereft of woods, that most of 
what we use is imported.” In France, a preparation of the root is still sometimes used as a 
purgative for children, and it is also thought beneficial in colds. In Hampshire it is known 
under the name of Adder’s Fern ; in Herefordshire, under that of Golden-locks and Golden 
Maidenhair. 
The fronds of the Common Polypody rise from a branched, creeping rootstock, which is 
thickly covered with brown scales ; these fronds have a naked stipes, often nearly as long as 
the leafy portion. The fern varies a great deal in size : sometimes the fronds are as much as 
a foot, or even a foot and a half in length ; at others they do not exceed a couple of inches, 
this latter being the case with specimens growing on walls. They are somewhat tough or 
leathery in texture, dark-green above, and paler below, their general outline being narrowly 
ovate or oblong ; the segments are simple, sometimes rather serrated, and usually blunt at 
PORTION OF FROND OF POLYPODIUM CAMBRICUM. 
the apex. The veins are prominent, the central one being alternately branched, and these 
branches being again divided. Each sorus originates at the apex of a veinlet. The bright 
yellow sori are conspicuous and well known. Mr. Moore points out that the common Polypody 
differs from all the other British species associated with it in the character of having its 
fronds articulated with the rhizome — that is, attached in such a manner that they separate 
spontaneously as they approach decay. 
The Polypody is a very variable species, and a large number of varieties have been named 
and described, many of which are based on the various ways in which the pinnae are cut 
and divided. The most elegant of these is named cornubiense ; of portions of a frond of this 
variety we give figures on page 164. Another very striking form is that known as the Welsh 
Polypody ( cambricum ), of which the figure of a portion of a frond is appended. This, as its 
name implies, was originally found in Wales ; the regularly bipinnatifid fronds are divided 
into narrow segments, very variable in shape, and they are always barren. This form has 
been met with several times in a wild state ; in cultivation it is not uncommon. The form 
semilacerum , often called the Irish Polypody, having been first found in Ireland, although it 
has since been met with in many other localities, is the most divided of all the fertile forms 
of the plant ; it bears a general likeness to cambricum, except in its fertility, and like it is 
