Description from Flora of China
Plants evergreen. Rhizome long creeping, up to 2 cm in diam., apex with sparse adpressed brown scales; fronds approximate. Fertile frond up to 1 m; stipe shiny, pale brown or gray-stramineous, shorter than lamina, 2-3 mm in diam. at base, grooved on adaxial side; lamina 2-pinnate with pinnatisect pinnules, or base almost 3-pinnate, broadly ovate-deltoid, up to 70 × 50 cm; pinnae ca. 12 pairs, alternate or subopposite, subspreading, slightly asymmetrical with broader basiscopic pinnules, basal pinnae largest, up to 40 × 15 cm, basal pinnules markedly shorter; pinnules up to 13 pairs, alternate, spreading, nearly symmetrical, lanceolate, up to 9 × 3 cm, base truncate, shortly stalked or adnate, pinnatisect close to costa, apex acuminate or acute (occasionally rounded); basal acroscopic pinnules smaller, close to rachis, basal basiscopic pinnules oblique, pinnule lobes ca. 5 pairs, elliptic-lanceolate, up to 1.5 cm × 5 mm, base adnate, pinnatifid, apex rounded; pinnule lobes of ordinary (non-basal) pinnules up to 10 pairs or more, elliptic or rectangular, margin shallowly lobate or crenate, apex rounded or truncate; veins visible abaxially, not prominent adaxially, veinlets up to 6 pairs, forked or simple. Lamina thinly herbaceous when dry, brown, glabrous adaxially; rachis, costae, and costules abaxially with short glandular hairs. Sori orbicular, subcostular, 1 or 2 pairs per lobe, or single. Spores nearly semicircular in equatorial view, perispore prominent, with few rugate projections.
Cornopteris pseudofluvialis is very similar to C. banajaoensis in the lamina shape and dissection but differs by the rhizome long creeping and the rachis, costae, and costules abaxially with dense short glandular hairs.
● Evergreen broad-leaved forests, beside streamlets; 1500-2700 m. SE Yunnan (Wenshan, Xinping).