Tanakaea radicans Franch. & Sav.

Herbs 6.5-12.5 cm tall. Rhizomes transversely elongate, ca. 2 mm in diam. Leaves all basal; petiole 1.1-6.5 cm, dark brown villous, sometimes hairs glandular tipped; leaf blade abaxially pale green, adaxially bright green, ovate to broadly so or elliptic, 1.1-3 × 0.8-2.9 cm, subleathery, both surfaces brown glandular hairy (sometimes hairs glandular tipped), base rounded or subcordate, margin serrate, apex acute. Inflorescence cymose, dense, 2.8-3.5 cm, brown glandular villous. Flowers whitish, small, apetalous. Sepals narrowly ovate to lanceolate, 1.5-1.9 × 0.4-0.6 mm, glabrous except margin sparsely glandular hairy, 1-veined, apex acute. Filaments 3.3-3.5 mm. Carpels ca. 4 mm, connate proximally; ovary very shallowly subsuperior, appearing almost superior; styles 2. Capsule ca. 4 mm; carpels divergent. Fl. Apr-Oct. 2n = 14*.

Wet shaded rocks. S Sichuan (Emei Xian, Nanchuan Xian, Pingshan Xian) [Japan].

Tanakaea omeiensis Nakai; T. omeiensis var. nanchuanensis W. T. Wang.

Tanakaea radicans, the Japanese foam flower, is a member of the Saxifrage family native to Japan, and is the sole species in the genus Tanakaea. It is named after the Japanese botanist Tanaka Yoshio. It was initially described by Ludovic Savatier and Adrien René Franchet.

Tanakaea radicans propagates via rhizomes similar to the runners of a strawberry. Its preferred habitat in the wild is shady, damp rocky soil.