Herbs perennial, erect. Leaves large, petiolate. Inflorescences slender terminal thyrses; bracts and bracteoles minute. Pedicel short. Calyx campanulate, membranous, prominently 10-veined and dilated in fruit; teeth 5, posterior tooth largest, apex truncate, conspicuously revolute in fruit; lateral teeth triangular-lanceolate, anterior teeth narrowly oblong-lanceolate. Corolla tube elongated, exserted, slender, dilated at throat, 2-lipped; upper lip straight, oblong, slightly concave; lower lip spreading, 3-lobed; middle lobe larger than lateral lobes, entire. Stamens 4, anterior 2 longer, ascending to underside of upper corolla lip, parallel, close together; filaments ciliolate basally; anthers ovoid, cells 2, divaricate, apex confluent. Style apex unequally 2-cleft. Disc apex truncate. Nutlets flattened, triquetrous, globose, shiny, pitted.

Monotypic: China, Myanmar, Vietnam.