[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.
