Description from Flora of China
Shrubs evergreen or deciduous, 1–2 m tall, rarely small trees to 8 m tall. Leaves petiolate; petiole rounded; leaf blade linear-lanceolate to broadly ovate, papery, subleathery, or leathery, glabrous or pubescent; veins 5–9, inconspicuous or conspicuous. Flowers ca. 3–5 mm in diam. Petals green or reddish purple, triangular ovate, valvate. Fruit green when young, turning red and eventually black when mature, subglobose, ovoid, or oblong, green when young.
Helwingia argyi H. Léveillé & Vaniot is a synonym of Stemona japonica (Blume) Miquel in the Stemonaceae (see Fl. China 24: 70. 2000).
Geographical distribution is the same as that of the family.