Herbs, perennial, epipetric or rarely terrestrial, rhizomatous, stemless. Leaves many, basal; leaf blade puberulent to villous, rarely glabrescent, base cuneate to subcordate. Inflorescences lax, axillary, 1-10-flowered cymes; bracts 2, opposite. Calyx actinomorphic, 5-sect from base to 5-lobed from above middle; segments equal to subequal. Corolla orange to yellow or white, rarely pink, zygomorphic, inside glabrous to puberulent, rarely pilose near base; tube narrowly funnelform to cylindric, slightly gibbous abaxially, longer than limb, 3-8 mm in diam.; limb 2-lipped to slightly 2-lipped; adaxial lip 2-lobed, emarginate, or rarely undivided, shorter than abaxial lip; abaxial lip 3-sect from base, lobes equal or central longer than laterals, apex rounded or rarely acute. Stamens 4, adnate to corolla tube above or rarely below middle, included or rarely exserted; anthers basifixed, coherent in pairs, thecae divergent, not confluent, dehiscing longitudinally; connective not projecting; staminode 1, adnate to adaxial side of corolla tube. Disc ringlike or rarely cupular. Ovary narrowly oblong, 1-loculed; placentas 2, parietal, projecting inward, 2-cleft. Stigmas 2, equal, 2-lipped, undivided. Capsule straight in relation to pedicel, oblong lanceolate to oblanceolate, much longer than calyx, dehiscing loculicidally to base; valves 2, straight, not twisted. Seeds unappendaged.

* Twelve species: endemic to China.

Ancylostemon flabellatus C. Y. Wu ex H. W. Li (Bull. Bot. Res., Harbin 3(2): 16. 8. 1983) is not included in the treatment because it is known only from fruiting specimens and cannot be definitively placed in Pan's classification (Fl. Reipubl. Popularis Sin. 69: 190-203. 1990). Its placement in Ancylostemon is uncertain since other genera (e.g., Tremacron, Isometrum, and Oreocharis) are virtually indistinguishable using vegetative or fruit characters.