Sporangia borne on the upper part of the free veins inside the margins, in
dot-like masses, but may run together, as in the continuous fruiting line
of the bracken. Indusium formed of the reflexed margins of the fertile
segments which are more or less membranous. (Pellæa, from the Greek
_pellos_, meaning dusky, in allusion to the dark stipes.)
(1) PURPLE CLIFF BRAKE. _Pellæa atropurpùrea_
Stipes dark purple or reddish-brown, polished and decidedly hairy and
harsh to the touch, at least on one side. Fronds coriaceous, pale, simply
pinnate, or bipinnate below; the divisions broadly linear or oblong, or
the sterile sometimes oval, chiefly entire, somewhat heart-shaped, or
else truncate at the stalked base. Veins about twice forked. Basal scales
extending into long, slender tips, colorless or yellow.
[Illustration: Purple Cliff Brake. _Pellæa atropurpurea_]
Another name is "the winter brake," as its fronds remain green throughout
the winter, especially in its more southern ranges. It grows on rocky
ledges with a preference for limestone, and often in full sun. In large and
mature fronds its pinnæ are apt to be extremely irregular. While its stipes
are purplish, its leaves are bluish-green, and its scales light-brown or
yellow. Strange to say, this brake of the cliffs thrives in cultivation.
Woolson says of it, "This fern is interesting and valuable. It is not only
beautiful in design, but unique in color, a dark blue-green emphasizing
all the varying tints about it--a first-class fern for indoor winter
cultivation. It is a rapid grower, flourishing but a few feet from coal
fire or radiator, in a north or south window. It quickly forgives neglect,
and if allowed to dry up out of doors or indoors, recovers in due time when
put in a moist atmosphere. It makes but one imperative demand, and that is
the privilege of standing still. Overzealous culturists usually like to
turn things around, but revolving cliffs are not in the natural order of
things. The slender black stipes are very susceptible to changes of light
and warped and twisted fronds result."
Dry, calcareous rocks, southern New England and westward. Rare. Var.
_cristata_ has forked pinnæ somewhat crowded toward the summit of the
frond. Missouri.
(2) SMOOTH CLIFF BRAKE
_Pellàea glabella. Pellàea atropurpùrea_, var. _Bushii_
Naked with a few, scattered, spreading hairs, smooth surface and dark
polished stipes. Rhizome short with membranous, orange or brown scales
having a few bluntish teeth on each edge. Pinnæ sub-opposite, divergent,
narrowly oblong, obtuse; base truncate, cordate or clasping, occasionally
auricled; lower pinnæ often with orbicular or cordate pinnules. Sterile
pinnæ broader, bluish or greenish glaucous above, often crowded to
overlapping. The smooth cliff brake has a decidedly northern range, growing
from northern Vermont to Missouri, and northwestward, but found rarely, if
at all, in southern New England.
[Illustration: Dense Cliff Brake. _Cryptogramma densa_ (From Waters's
"Ferns," Henry Holt & Co.)]
(3) DENSE CLIFF BRAKE
_Cryptográmma densa. Pellaèa densa_
Modern botanists are inclined to place the dense cliff brake and the
slender cliff brake under the genus _Cryptográmma_, which is so nearly like
_Pellaea_ that one hesitates to choose between them. The word Cryptográmma
means in Greek a _hidden line_, alluding to the line of sporangia hidden
beneath the reflexed margin.
The dense cliff brake may be described as follows:
Stipes three to nine inches tall, blades one to three inches,
triangular-ovate, pinnate at the summit, and tripinnate below. Segments
linear, sharp-pointed, mostly fertile, having the margins entire and
recurved, giving the sori the appearance of half-open pods. Sterile
fronds sharply serrate. Stipes in dense tufts ("_densa_") slender, wiry,
light-brown.
This rare little fern is a northern species and springs from tiny crevices
in rocks, preferring limestone. Like many other rock-loving species, it
produces spores in abundance, having no other effective means of spreading,
and its fertile fronds are much more numerous than the sterile ones, and
begin to fruit when very small. Gaspé and Mt. Albert in the Province of
Quebec, Grey County, Ontario, and in the far west.
(4) SLENDER CLIFF BRAKE
_Cryptográmma Stellèri. Pellaèa grácilis_
Fronds (including stipes) three to six inches long, thin and slender with
few pinnæ. The lower pinnæ pinnately parted into three to five divisions,
those of the fertile fronds oblong or linear-oblong; those of the sterile,
obovate or ovate, crenulate, decurrent at the base. Confined to limestone
rocks. Quebec and New Brunswick, to Vermont, Connecticut, Pennsylvania, and
to the northwest.
[Illustration: Slender Cliff Brake. _Cryptogramma Stelleri_]
We have collected this dainty and attractive little fern on the limestone
cliffs of Mt. Horr, near Willoughby Lake, Vt. It grew in a rocky grotto
whose sides were kept moist by dripping water. How we liked to linger near
its charming abode high on the cliff! And we liked also to speak of it by
its pleasing, simple name, "Pellæa gracilis," now changed for scientific
reasons, but we still like the old name better.
(5) THE ROCK BRAKE. PARSLEY FERN
_Cryptográmma acrostichòides_
Sterile and fertile fronds very dissimilar; segments of the fertile, linear
and pod-like; of the sterile, ovate-oblong, obtuse, and toothed. The plants
spring from crevices of rocks and are from six to eight inches high. Stipes
of the fertile fronds are about twice as long as the sterile, making two
tiers of fronds.
[Illustration: Parsley Fern or Rock Brake. _Cryptogramma acrostichoides_
(California and Oregon) (Herbarium of Geo. E. Davenport)]
The parsley fern is the typical species of the genus _Cryptográmma_. The
indusium is formed of the altered margin of the pinnule, at first reflexed
to the midrib, giving it a pod-like appearance, but at length opening out
flat and exposing the sporangia. Clute, speaking of this fern as "the rock
brake," calls it a border species, as its home is in the far north--Arctic
America to Lake Huron, Lake Superior, Colorado and California.