(From the Greek meaning many-footed, alluding to the branching rootstocks.)
Simple ferns with stipes articulated to the creeping rootstocks, which are
covered with brown, chaffy scales. Fruit-dots round, naked, arranged on the
back of the frond in one or more rows each side of the midrib. Sporangia
pedicelled, provided with a vertical ring which bursts transversely. A
large genus with about 350 species, widely distributed, mostly in tropical
regions.
(1) COMMON POLYPODY. _Polypodium vulgare_
Fronds somewhat leathery in texture, evergreen, four to ten inches tall,
smooth, oblong, and nearly pinnate. The large fruit-dots nearly midway
between the midrib and the margin, but nearer the margin.
[Illustration: Common Polypody. _Polypodium vulgare_]
Common everywhere on cliffs, usually in half shade, and may at times spring
out of decaying logs or the trunks of trees. As the jointed stipes, harking
back to some ancient mode of fern growth, fall away from the rootstocks
after their year of greenness, they leave behind a scar as in Solomon's
seal. The polypody is a gregarious plant. By intertwining its roots the
fronds cling together in "cheerful community," and a friendly eye discovers
their beauty a long way off. August. Abounds in every clime, including
Europe and Japan.
In transplanting, sections should be cut, not pulled from the matted mass.
Var. _cambricum_ has segments broader and more or less strongly toothed.
Var. _cristatum_ has the segments forked at the ends.
Several other forms are also found.
[Illustration: Fruited Frond]
[Illustration: The Common Polypody. _Polypodium vulgare_ (Photographed by
Miles Greenwood, Melrose, Mass.)]
(2) GRAY OR HOARY POLYPODY
_Polypodium incànum. P. polypodiòides_
Fronds oblong, two to seven inches long, deeply pinnátifid, gray and scurfy
underneath with peltate scales having a dark center. Fruit-dots rather
small, near the margin and obscured by the chaff.
[Illustration: Gray or Hoary Polypody. _Polypodium incanum_]
In appearance the gray polypody is much like the common species, as the
Greek ending _oides_ (like) implies. In Florida and neighboring states it
often grows on trees; farther north mostly on rocks. Reported as far north
as Staten Island. It is one of the "resurrection" ferns, reviving quickly
by moisture after seeming to be dead from long drouth. July to September.
Widely distributed in tropical America. Often called Tree-Polypody.