16. Scorpiothyrsus H. L. Li, J. Arnold Arbor. 25: 33. 1944.
卷花丹属 juan hua dan shu
Shrublets, erect, branched or not. Stems 4-sided but basally subterete, sulcate, pubescent or glabrous. Leaves petiolate; leaf blade usually papery, secondary veins 2-4 on each side of midvein, tertiary veins parallel. Inflorescences terminal, scorpioid, cymose panicles, usually pedunculate; bract small, caducous. Flowers small, 4-merous. Pedicel short, usually 4-sided. Hypanthium funnelform-campanulate, 4-sided, usually pubescent. Calyx lobes lanceolate, ovate, or orbicular, margin dentate, apex acute or apiculate. Petals obovate, orbicular, or subovate. Stamens 8, equal; filaments short; anthers oblong, base setose or not, apex obtuse; connective decurrent, sometimes forming a spur. Ovary half inferior, ovoid, 4-celled. Style filiform; stigma apiculate. Capsule subglobose; hypanthium turbinate to half globose, obtusely 4-sided, 8-ribbed. Seeds cuneate, small, minutely tuberculate.
● Three species: China (Guangxi, Hainan).
Scorpiothyrsus is highly distinct within the family in its scorpioid, cymose inflorescence panicles that bear numerous, very small, white or pink flowers.