Osmunda bipinnata Hooker (1857), not Linnaeus (1753).

Rhizome erect, woody. Fronds 2-pinnate, up to 1 m × 30 cm; stipe shiny, 25-30 cm, slender; lamina ovate-oblong, 30-45 × ca. 20 cm; pinnae 7-11 pairs, subopposite, ascending, ca. 4 cm apart, shortly stalked, sessile upward, oblong-lanceolate, 10-15 × ca. 4 cm, apex caudate, imparipinnate; pinnules 10-12 pairs, approximate, ovate or oblong, 1.5-2 × 0.8-1.2 cm, base obtuse, sessile, upper pinnule base connate; apical pinnae oblong, simple, sterile; middle pinnae pinnate with a large apical pinnule up to 4-5 cm and numerous smaller, oblong lateral pinnules; basal 4-7 pairs of pinnae like middle ones but shorter and often fertile, 4-5 × ca. 1 cm; fertile pinnules linear, 5-7 mm. Sporangia on margin of reduced basal pinnule.

Osmunda mildei was first described from Hong Kong and appeared to be extinct for almost a century. Recently, small populations in Shenzhen and S Jiangxi were discovered. It appears to be a native hybrid between O. japonica and O. vachellii or O. angustifolia. It differs from O. japonica by the terminal pinnule of each pinna elongated and much larger than the lateral ones on the same pinna.

● Locally rare, on hillsides in forests; 400-500 m. Guangdong, S Jiangxi.