Rhizomes long creeping, apex clothed with brownish ovate-lanceolate scales; fronds distant, sometimes approximate. Fertile fronds (16-)20-50(-76) cm; stipe stramineous, (8-)15-32(-51) cm, up to 3.5 mm in diam., base sparsely scaly, upper part glabrate; lamina pinnate-pinnatifid or 2-pinnate-pinnatipartite, deltoid-ovate, (7-)15-20(-27) × (7-)14-22(-30) cm, herbaceous or papery, base rounded, apex acuminate; pinnae (3-)5-8 pairs, opposite, oblique, basal 1-4 pairs stalked, articulate to rachis; basal pinnae largest, narrowly triangular, (4-)8-15(-18) × 3-7(-11) cm at base, base subtruncate, with stalk (0.8-)1-2.5(-3.5) cm, slightly oblique, pinnate-pinnatifid or pinnate-pinnatipartite, apex acuminate; pinnules 5-8 pairs, deltoid-lanceolate, base subtruncate, apex acuminate, opposite or subopposite; basal one to several pairs articulate to costa, usually sessile, sometimes basal pair shortly stalked, 1-3(-12) mm; basal basiscopic pinnules longest, 1-5(-7) × (0.7-)1-2.3 cm, descending; pinnule segments 5-10 pairs, oblong to narrowly ovate, base free or adnate to narrow wing, margin crenate, apex rounded-obtuse; second basal pair of pinnae (2-)4-5(-7.5) cm apart from basal pair, narrowly triangular, much smaller than lowest pinnae, 4-8(-12) cm; third and upper pairs of pinnae broadly lanceolate, gradually smaller; veins pinnate in segment, veins usually forked, sometimes simple, very oblique, visible; stipe apex, rachis, and costae with hyaline or pale yellow short glands. Sori small, orbicular or oblong, abaxial on veins, submarginal, exindusiate. Spore wall surface rugate, foveolate. 2n = 80, 160.
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Subspecies 2 (1 in the flora): North America, Asia.
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