Medium- to large-sized ferns with a usually extensive system of long-creeping, branched, subterranean, hairy rhizomes, often forming large clonal colonies. Leaves mostly 0.5–1.5 m long, rarely to 2.5 m long, glabrous or variously hairy, long-petiolate, the petioles grooved along the upper side. Leaf blades 2 to 3 times pinnately compound and lobed, broadly deltate to deltate-triangular, ovate-triangular, or nearly pentagonal, the ultimate lobes or segments rounded to pointed at the tip, with strongly recurved, often pale margins, these irregular and usually sparsely to densely fringed along the edge, acting as a pseudoindusium to cover the developing sporangia (a true, outward-oriented indusium absent or vestigial). Sporangia in a continuous band along the leaf margins, hidden by the pseudoindusium until maturity. Spores 64 per sporangium, brown, nearly spherical (slightly tetrahedral), with a 3-branched tetrad scar (trilete), 23–40 μm in diameter, the outer surface irregularly granular. Source documents: Tryon (1941), Tryon and Tryon (1982), Kramer (1990), Tryon and Lugardon (1991), Jacobs and Peck (1993), Mickel and Smith (2004).
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