Description from Flora of China
Herbs fleshy. Stems very short, branched or not. Flowers large, solitary or clustered at stem apex. Bractlets absent. Pedicel very long, erect. Calyx spathelike, apex acute or obtuse-rounded. Corolla tubular or campanulate, indistinctly bilabiate; upper lip 2-lobed; lower lip 3-lobed; lobes subrounded. Stamens 4, included; anthers adherent, 1 cell fertile, another reduced into a spur. Carpels 2; ovary usually 1-locular and parietal placentas 2 or 4, occasionally imperfectly 2-locular and placentas axile. Style slightly curved; stigma fleshy, peltate. Capsule dehiscing by 2 valves. Seeds numerous; testa reticulate.
About four species: Cambodia, China, India, Indonesia, Japan, Malaysia, Myanmar, Philippines, Sri Lanka, Thailand, Vietnam; three species in China.