Didissandra leucantha Diels, Repert. Spec. Nov. Regni Veg. Beih. 12: 487. 1922.

Petiole to 8 cm, brown villous and white puberulent; leaf blade subovate, 3-4.5 X 2-3.2 cm, appressed pubescent, abaxially brown villous along veins, margin coarsely crenate-dentate. Peduncle 14-18 cm, brown villous and puberulent. Pedicel 2-4 cm. Calyx segments oblong, ca. 4 mm. Corolla white, ca. 2.3 cm, outside minutely pilose; tube ca. 15 X 6-8 mm; lobes triangular-ovate, 5-6 mm. Stamens 4-7 mm; filaments glabrous. Ovary 6-7 mm. Fruit unknown.

We have not seen any specimens of Isometrum leucanthum. The above description is adapted from the protologue. This species differs from others in Isometrum in its long petiole and white corolla.

* Forests on slopes; ca. 3900 m. W Sichuan (Baiyü Xian, Batang Xian).