Description from
Flora of China
Bramia Lamarck; Herpestis C. F. Gaertner; Mella Vandelli; Sinobacopa D. Y. Hong.
Herbs, erect or creeping. Leaves opposite. Flowers solitary, axillary or in terminal racemes. Bracteoles 1 or 2 or absent. Sepals (4 or)5, entirely free, imbricate, upper 1 largest, lower 2 next large, lateral 2 innermost and narrowest. Corolla tube tubular; limb patent, conspicuously or obscurely 2-lipped; lower lip 3-lobed; upper lip 2-lobed. Stamens 4, didynamous or equal in length, very rarely 5; anther locules parallel, free. Stigma dilated, capitate or 2-lobed. Capsule ovoid or globose, 2-grooved, 4-valved. Seeds numerous, minute.
About 60 species: tropics and subtropics, mainly in America; three species in China.