Simulata means resembling, in this case forms of the lady fern, Athyrium filix-femina, according to George Davenport.
Rhizome: long-creeping, branching, some stipes distantly spaced, some closely spaced, ovate, pale brown scales, mostly at the apex.
Frond: 80 cm high by 15 cm wide, deciduous, monomorphic, though sterile fronds arching, fertile taller, more erect, with longer stipes, blade/stipe ratio: 1:1 to 2:1, fertile fronds having longer stipes.
Stipe: brown at base, shading to green, sparsely set with tan, ovate, scales, vascular bundles: 2, oblong, at 90°, at stipe base, merging above to a u-shape.
Blade: 1-pinnate-pinnatifid, lanceolate, widely separated pinnae, tapering to the tip, widest at or just above the lowest pinna, membranous, pale green, short, whitish hairs, falling soon, and yellow glands, also blade tissue with numerous reddish to orangish, resinous, shiny, sessile, hemispheric glands.
Pinnae: 16 to 18 pair, lanceolate, long tapering, less incised near the ends, 2 cm wide, subopposite; pinnules 15 pairs ±, blunt, fertile pinnules slightly inrolled, not strongly; costae grooved above, discontinuous with the rachis; margins entire; veins free, simple.
Sori: round, midway between the margin than the costule, merging into each other, indusium: reniform, whitish, then tan, at a sinus, sporangia: brown.
Dimensionality: lowest pair of pinnae bending down, forward.
Habitat: moist, shady woods, cedar and sphagnum swamps.
Distribution: northeastern North America.
Hardy to -30°C, USDA Zone 4.
The free veining (not forking) and the bending forward, down of the lowest pinna pair separates this from T. palustris. The sori are distinct here, the indusium present, neither true with T. palustris. Confusion with T. noveboracensisis precluded by the latter's tiny lowest pinnae.
Aspidium simulatum Davenport
Parathelypteris simulata (Davenport) Holttum
Dryopteris simulata Dav.
Lastrea simulata Dav.
Nephrodium simulatum Dav. ex Diels