Description:
This perennial fern forms a loose rosette of a few basal leaves about
3-4½' tall. Each compound leaf is 2-3' long, 1-1½' across, and
ovate in outline; its structure is mostly pinnate-pinnatifid, although
it is somewhat bipinnate below because some of the lower leaflets have
distinct subleaflets. The tip of each
compound leaf has a tendency to taper abruptly. Each compound leaf has
12-18 pairs of leaflets that are mostly perpendicular to the rachis
(central leaf stalk) and arranged alternately. The longest leaflets are
located toward the middle of each compound leaf. Each leaflet
has 14-24 pairs of distinct lobes or subleaflets, forming an
oblong-elliptic shape with a tapering tip. The longest lobes or
subleaflets are located toward the middle of each leaflet. The lobes or
subleaflets are short-oblong in shape, curving slightly outward toward
the tip of each leaflet. Their margins are slightly crenate to slightly
crenate-serrate.
The upper surface of the compound leaf is medium to
dark green and hairless, while the its lower surface is slightly more
pale and hairless. The rachis is light green or grayish green and
glabrous to slightly scaly (usually the latter). The petiole is about
one-third of the length of the compound leaf. It is light green to
grayish green and more or less covered with brownish scales (more so at
the bottom than at the apex). The sori (spore-bearing structures)
occur on the lower side of the lobes or subleaflets. Each lobe or
subleaflet typically has 6-8 pairs of sori along its midvein.
Immature sori and their indusia (protective membranes) are light
green to light gray, circular in shape, and non-glandular. At maturity
during mid-summer, the sori turn brown and release their tiny
spores to the wind. The root system consists of a short scaly rhizome
and fibrous roots. The leaves of this fern are deciduous, dying down
during the winter.
Cultivation:
The preference is dappled sunlight to medium shade, moist
to mesic
conditions, and a loose fertile loam with decaying organic matter. This
fern also requires relatively high humidity levels and protection from
strong wind. If these conditions are met, it will adapt to cultivation
in gardens.
Range
& Habitat: The native Goldie's Fern occurs in
scattered
counties in the northern half of Illinois and also in the southern
section of the state (see
Distribution
Map).
It is rare in
Illinois, although not currently listed as threatened or endangered.
Habitats consist of rich mesic woodlands, wooded ravines, shaded areas
along the bases of cliffs and bluffs, and edges of swamps. This fern
occurs in high quality habitats – typically old-growth deciduous
woodlands, where such trees as maple, basswood, or beech are dominant
and competition from shrubs is reduced.
Faunal
Associations: A small number of insects has been found to
feed
on one or more species of
Dryopteris
spp. (Shield Ferns, Wood Ferns).
These species include the aphid
Amphorophora
ampullata, the plant bug
Monalocoris americanus,
caterpillars
of
Herpetogramma
theseusalis (Translucent Cat, Herpetogramma Moth), and
caterpillars of
Stathmopoda elyella
(Iridescent Gold Moth); see Blackman & Eastop (2013), Knight
(1941), Eastman (1992), and Microleps website (2010). The plant bug and
Iridescent Gold Moth feed on developing sporangia or spores on
the leaf undersides. Mammalian herbivores usually avoid the foliage of
Dryopteris spp.,
which is known to be toxic for some species.
Photographic
Location: A shade garden at the Toledo Botanical Garden
in Toledo, Ohio.
Comments: This is the largest fern of its genus in
Illinois and also
one of the most attractive. Goldie's Fern can be distinguished from
similar species in its genus by the large size of its compound leaves;
they tend
to taper abruptly at their tips, rather than gradually. On the
undersides of the leaflet lobes or subleaflets, its sori are located
near their midveins, rather than near their margins or halfway between
their midveins and margins. Goldie's Fern is regarded as one of the
parents of a rare hybrid,
Dryopteris
× clintoniana (Clinton's Wood
Fern). This latter species differs from Goldie's Fern by
having sterile leaves that are evergreen and sori on fertile leaves
that are
located halfway between the margins and midveins of its leaflet lobes
or subleaflets. In addition, its leaves are more narrow in
shape.