um vulgare_

PHYLLITIS SCOLOPENDRIUM

Fronds thick and leathery, oblong-lanceolate from an auricled, heart-shaped
base, ten to twenty inches long and one to two inches wide. Margin entire,
bright green.

In shaded ravines under limestone cliffs. Chittenango Falls, and
Scolopendrium Lake, central New York, and Tennessee. Also, locally in
Ontario and New Brunswick. One of the rarest of our native ferns, although
very common in Great Britain. This plant is said to be easily cultivated,
and to produce numerous varieties. According to Woolson, "No rockery is
complete without the Hart's Tongue, the long, glossy, undulating fronds
of which are sufficiently unique to distinguish any collection." In
cultivation it "needs light protection through the winter in northern New
England."

[Illustration: Hart's Tongue. _Scolopendrium vulgare_ (Base of calcareous
rocks, Owen Sound, Ontario, Canada)]

WALKING FERN. WALKING LEAF

_Camptosorus_

Fruit-dots oblong or linear as in _Asplenium_, but irregularly scattered on
either side of the reticulated veins of the simple frond, the outer ones
sometimes confluent at their ends, forming crooked lines (hence, the name
from the Greek meaning crooked sori). Only one species within our limits.

_Camptosorus rhizophyllus_

Fronds evergreen, leathery, four to eighteen inches long, heart-shaped at
the base, but tapering towards the apex, which often roots and forms a
new plant. Veins reticulated. The auricles of this species are sometimes
elongated and may even take root.

This curious and interesting fern is one of the finest for rockeries, the
tips taking root in rock-fissures. Shaded limestone, or sometimes other
rocks. Shapleigh and Winthrop, Me., rarely in New Hampshire (Lebanon),
and Connecticut, Mt. Toby, Mass., and western New England; also Canada to
Georgia and westward.

[Illustration: Walking Fern. _Camptosorus rhizophyllus_]

THE SHIELD FERNS

THE CHRISTMAS AND HOLLY FERNS

_Polystichum_

These have been grouped with the wood ferns, but are now usually placed
under the genus _Polystichum_, which has the sori round and covered with
a circular indusium fixed to the frond by its depressed center. The wood
ferns, on the other hand, have a kidney-shaped indusium attached to the
fronds by the sinus. (_Polystichum_ is the Greek for many rows, the sori of
some species being in many ranks.)

(1) THE CHRISTMAS FERN

_Polystichum acrostichoides. Aspidium acrostichoi