296 
Choice Ferns for Amateurs. 
PhATYCKRlVM~co?ithmed. 
P. Hillii. 
This very handsome Queensland Fern is very closely 
related to P. alcicorne majus — ^so much so that, until the 
plants attain their full development, it is very diflScult to 
distinguish one from the other. The repeated forking of 
the frond divisions differentiate it from majus; while it is 
altogether stiff er in habit. 
PLATYLOMA. See Pellaea. 
PLEOCNEMIA. See Nephrodium. 
PLEOPELTIS. See Polypodium. 
PLEURIDIUM. See Polypodium. 
POLYBOTRYA. See Acrostichum. 
POLYPODIUM. 
An exceedingly large genus — the most ex- 
tensive, in fact, of the Natural Order Filices, As 
now understood, it comprises Camiiyloneuron, 
Cyrtomiylilehium, Dictyopteris, Dipteris, Drynaria^ 
E up olyfp odium, Goniopklehium, Gonioyteris, Gram- 
mitis, Niphobolus, Phegopteris, Phlebodium, Phy- 
matodes, Pleopeltis, and Pleuridium, 
The Polypodiums, both British and exotic, are 
of two different structures and of various habits. A 
small proportion of them, such as our common 
" Oak and " Beech Ferns (P. Dryopteris and P. 
Phegopteris), are deciduous, and provided with 
slender rhizomes which delight in running under- 
ground, especially in partly-decayed vegetable 
matter; the foliage of these species, as a rule, is of a 
soft, papery texture. The majority of them, how- 
ever, are of an evergreen nature, having fronds of a 
somewhat leathery texture, produced from rhizomes 
which prefer being kept above or close to the surface 
of the ground. Those species which are provided 
with underground rhizomes may be either grown in 
pots or planted in any part of the stove, the cool 
Fernery, or the outdoor rockery, according to their 
native habitats; and for these, a mixture composed 
of two parts fibrous loam, one part leaf mould, and 
one part sharp silver sand, answers all require- 
ments. This treatment also applies to the species 
