Under this designation Clute has grouped three of the shield ferns, which
have a close family resemblance, and has thus distinguished them from the
wood ferns, which also belong to the shield fern family.
(1) THE MARSH FERN
_Aspídium thelýpteris_. THELÝPTERIS PALÚSTRIS
_Dryópteris thelýpteris. Nephròdium thelýpteris_
[Illustration: The Marsh Fern]
These are all good names and each one is worthy to be chosen. _Aspídium_,
Greek for shield, in use for a century, adopted in all the seven editions
of Gray's Manual, is still the most familiar and pleasing term to its
friends. _Dryópteris_, Greek for oak fern, has been chosen by Underwood
and Britton and Brown and has grown in favor. _Nephròdium_, meaning
kidney-like, favored by Davenport, Waters and, of late, Clute, is a most
fitting name. THELÝPTERIS, meaning lady fern, is found to be the earliest
name in use and according to rule the correct one.
[Illustration: The Marsh Fern. _Aspidium Thelypteris_]
Fronds pinnate, lanceolate, slightly or not at all narrowed at the base.
Pinnæ horizontal or slightly recurved, linear-lanceolate and deeply
pinnatifid. Lobes obtuse, but appear acute when their margins are reflexed
over the sori. Veins once forked. Indusium minute. Stipes tall, lifting the
blades ten to fifteen inches above the mud, whence they spring.
The fronds of the marsh fern are apt to be sterile in deep shade. It may be
readily distinguished from the New York fern by its broad base, instead of
tapering to very small pinnæ; by its long stalk, lifting the blade up into
the sunlight, and by the revolute margins of the fertile fronds, which have
suggested for it the name of "snuff-box" fern. It is separated from
the Massachusetts fern by its forked veins. Common in marshes and damp
woodlands; Canada to Florida and westward. While the marsh fern loves
moisture and shade it is sometimes found in dry, open fields. Miss Lilian
A. Cole, of Union, Me., reports a colony as growing on land above the swale
in which Twayblade and Adder's Tongue are found, "around rock heaps in
open sunlight on clay soil, but homely and twisted," as if a former woodsy
environment had been long since cleared away while the deserted ferns
persisted.
(2) MASSACHUSETTS FERN
_Aspidium simulàtum_. THELÝPTERIS SIMULÀTA
_Dryópteris simulata. Nephròdium simulàtum_
Fronds pinnate, one to three feet long, oblong-lanceolate, somewhat
narrowed at the base. Pinnæ lanceolate, deeply pinnatifid, the lower most
often turned inward. Veins simple. Indusium glandular. Sori rather large.
Resembles the marsh fern, of which it was once thought to be a variety.
In some respects it is also like the New York fern, and is in fact
intermediate between the two.
[Illustration: Massachusetts Fern. _Aspidium simulatum_ 1. Sterile Frond.
2. A Fruiting Pinnule. 3. Pinnule enlarged showing venation (From the "Fern
Bulletin")]
That it is a distinct species was first pointed out by Raynal Dodge in
1880, and it later was named _simulàtum_ by Geo. E. Davenport because of
its similarity to a form of the lady fern. It may be identified by its
thin texture and particularly by its simple veins. On account of its close
resemblance to the marsh fern, Clute would call it "The lance-leaved Marsh
Fern," instead of the irrelevant name of Massachusetts Fern. Woodland
swamps usually in deep shade, New England to Maryland and westward. Often
found growing with the marsh fern.
(3) NEW YORK FERN
_Aspidium noveboracénse_. THELÝPTERIS NOVEBORACÉNSIS
_Dryópteris noveboracénsis. Nephròdium noveboracénse_
Fronds pinnate, tapering both ways from the middle. Pinnæ lanceolate,
pinnatifid, the lowest pairs gradually shorter and deflexed. Veins simple.
Indusium minute and beset with glands.
[Illustration: New York Fern. _Aspidium noveboracense_]
Very common in woodlands, preferring a dryer soil than the marsh fern.
August. The fronds are pale green, delicate and hairy beneath along the
midrib and veins.
[Illustration: Sori of New York Fern (From Waters's "Ferns," Henry Holt &
Co.)]
[Illustration: New York Fern. _Aspidium noveboracense_]
When bruised its resinous glands give out a pleasing, ferny odor. This
species can be distinguished from every other by the greatly reduced pinnæ
at its base. Throughout North America east of the Mississippi.