Vines. Roots long fusiform. Stems many branched, usually 40--70 cm, ribbed, base woody. Leaves alternate; petiole sometimes curved, 1--3.5 cm, slender; leaf blade lanceolate, 5--7.5(--9.5) × 0.6--2(--4.5) cm, veins 5, base subrounded to cuneate, margin minutely undulate, apex acuminate to caudate-acuminate. Inflorescences axillary, racemes, 2--6-flowered; pedicel ca. 5 mm, slender, articulate at middle; bracts subulate, small. Flowers small. Perianth segments purplish red tinged with green, broadly ovate-lanceolate, ca. 10 × 3 mm. Stamens slightly shorter than perianth; filaments free, ca. 1 mm, slender; anthers ca. 2 mm, slender; appendages partially adherent, adaxial one 2--3 mm. Ovary ovoid, ca. 1.5 × 1 mm. Fl. Apr--Jul.

The roots are used medicinally.

* Streamsides, rock crevices in valleys, waste places; ca. 700 m. Hainan.