15 . 
THE THREE-BRANCHED POLYPODY. 
Polyp odium dry op ter ii>. 
Plate 7 , Fig 4 , Page 253 . 
Amongst our native Polypodies this species is unques- 
tionably the most delicate in form and habit, as well as 
the most beautiful in colouring. Yet this tender little 
Fern takes one of its names from a forest tree — dry op ter is 
being derived from drus, ‘ an oak,’ and pteris, ‘ a Fern.’ 
It is indeed frequently called ‘the Oak Fern,’ on account 
of some not perhaps entirely fanciful resemblance, in 
miniature, of the frond to an oak-tree. It is found in 
very much the same kind of situations as Phegopteris, 
namely, in damp woods, in moist mountainous districts, in 
stony hedge-banks, and on the margins of moorland streams. 
But in such places it selects a somewhat drier position than 
Phegopteris , though it equally avoids the sunlight, which 
would prejudicially affect the delicate texture and colouring 
of its beautiful fronds. 
Description.— It would be by no means inapt to compare 
generally a frond of Poly podium dryopteris to three crossed 
fronds of Phegopteris — one placed in a perpendicular position 
and the other two at right angles to it, with their stalks or 
stipides in a line. The description is, of course, not an 
exact one, but it gives a general idea of the form of the 
frond, which, as its fairly descriptive name implies, is 
distinctly tliree-branched. According to the conditions of 
growth, the fronds of this little Fern grow to a length of 
K 
