Description from Flora of China
Herbs or shrubs. Leaves petiolate, dentate. Verticillasters 6- to many flowered, in racemes or panicles; bracts early deciduous or absent. Flowers pedicellate. Calyx ovoid-campanulate to campanulate, 5-toothed or conspicuously 2-lipped, posterior tooth larger; fruiting calyx dilated, declinate or recurved, throat glabrous or villous. Corolla much exserted, erect or recurved, 2-lipped; upper lip (3- or) 4-lobed, strongly reflexed; lower lip entire, elongated, navicular, narrowed at base. Stamens 4, declinate, included within lower lip; filaments connate or free, rarely adnate to corolla tube; anther cells apex confluent. Style apex equally 2-cleft. Nutlets ovoid to globose, smooth, tuberculate or not.
About 90(-150) species: tropics of E hemisphere, Australia; six species in China.
Many workers believe that the type species of Coleus is congeneric with Plectranthus s. str., a large predominantly African genus, but some of the Asian species have never been
formally transferred to that genus. There is much less agreement on the status of other segregate genera.