Serpentina is a small evergreen erect shrub with whorled branches and milky sap. Leaves are opposite, entire, oblong-elliptic, up to 30 centimeters long. Flowers are white, clustered in axillary cymes, with slender corolla tube and 5 spreading lobes. Fruit is a small drupe, shiny, black or purplShrubs to 1 m tall, erect, glabrous. Stems usually unbranched, slender, straw colored. Leaves grouped near stem apex, in whorls of 3-5; petiole 1-1.5 cm; leaf blade narrowly elliptic or obovate, membranous, 7-17 X 2-9 cm, base cuneate, apex acuminate or rarely obtuse; lateral veins 7-15 pairs. Cymes congested; peduncle 5-13 cm, red or reddish. Pedicel and calyx red or reddish. Corolla white, tube cylindric, 1-1.8 cm, inflated at middle and pilose inside distal half; lobes obliquely suborbicular, 1.5-3.5 mm. Stamens inserted at middle of corolla tube. Ovaries connate in basal half. Drupes ellipsoid, ca. 8 mm, connate for half their length. (Flora of China)