(1) THE MARSH FERN

Aspidium thelypteris.  THELYPTERIS PALUSTRIS Dryopteris thelypteris.  Nephrodium thelypteris

[Illustration:  The Marsh Fern]

These are all good names and each one is worthy to be chosen. Aspidium, 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. Dryopteris, Greek for oak fern, has been chosen by Underwood and Britton and Brown and has grown in favor. Nephrodium, meaning kidney-like, favored by Davenport, Waters and, of late, Clute, is a most fitting name.  THELYPTERIS, 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.  Pinnae 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 pinnae; 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 simulatum.  THELYPTERIS SIMULATA Dryopteris simulata.  Nephrodium simulatum

Fronds pinnate, one to three feet long, oblong-lanceolate, somewhat narrowed at the base.  Pinnae 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 simulatum 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.