Description from Flora of China
Herbs, shrublets, or shrubs, erect or stoloniferous. Stems usually 4-sided. Leaves petiolate; leaf blade secondary veins 2-4 on each side of midvein, tertiary veins parallel, margin entire or denticulate. Inflorescences terminal, subterminal, or axillary, umbellate, cymose umbellate, cymose paniculate, or rarely capitate, usually long pedunculate; bracts caducous. Flowers (3 or)4-merous. Pedicel bracteolate. Hypanthium funnel-shaped or subcampanulate, (3 or)4-sided, longitudinal (6 or)8-ribbed. Calyx lobes (3 or)4. Petals ovate, obovate, or broadly ovate, usually oblique. Stamen whorls ± equal in shape and length or only slightly unequal in length; anthers subulate to oblong-linear, base tuberculate, expanded, or not appendaged; connective decurrent, forming a short spur. Ovary inferior, urceolate, rarely cup-shaped, (3 or)4-celled. Style filiform; stigma acute. Capsule cup-shaped or globose-urceolate; hypanthium 8-ribbed. Seeds small, cuneate, angulate, densely tuberculate or not.
Although the genus has recently been revised (Hansen, Bull. Mus. Natl. Hist. Nat., B, Adansonia 14: 355-428. 1993 ["1992"]), the Chinese species are poorly collected and understood.
About 56 species: China, Indonesia, Malaysia, Myanmar, Thailand; 24 species (19 endemic) in China.