Description from Flora of China
Dasydesmus Craib; Perantha Craib.
Herbs, perennial, epipetric, rarely terrestrial, rhizomatous, stemless. Leaves many, basal; leaf blade puberulent to woolly, rarely glabrous or glabrescent, base cuneate to subcordate. Inflorescences sometimes umbel-like, lax or dense, axillary, 1- to many-flowered cymes; bracts 2, rarely apparently absent or 3, opposite, rarely whorled. Calyx actinomorphic, 5-sect from base; segments equal. Corolla purple to blue or white or yellow to red, zygomorphic, inside glabrous or puberulent; tube campanulate-cylindric to broadly tubular, sometimes ampliate basally, throat sometimes constricted, 1-4 X longer than limb, 2-8(-12) mm in diam.; limb slightly 2-lipped to 2-lipped; adaxial lip 2-lobed, slightly shorter than to nearly as long as abaxial lip; abaxial lip 3-lobed to 3-sect, lobes equal or subequal, apex rounded to acute. Stamens 4, adnate to corolla tube near base to near middle, included, rarely exserted; anthers basifixed, rarely dorsifixed, free, thecae parallel, not confluent, seldom horseshoe-shaped, then thecae divaricate and confluent at apex, dehiscing longitudinally, rarely transversely; connective not projecting; staminode 1, adnate to adaxial side of corolla tube, rarely absent. Disc ringlike. Ovary oblong, 1-loculed; placentas 2, parietal, projecting inward, 2-cleft. Stigmas 2, equal, oblate, undivided or rarely 2-lobed, or stigma 1, terminal, oblate to capitate, undivided. Capsule straight in relation to pedicel, oblanceolate-oblong to oblong, much longer than calyx, dehiscing loculicidally to base; valves 2, straight, not twisted. Seeds unappendaged.
About 28 species: southern China, Thailand, Vietnam; 27 species in China.
Oreocharis rhytidophylla C. Y. Wu ex H. W. Li, which is compared to and discussed under O. benthamii var. reticulata Dunn, is omitted from this treatment because it is known only from fruiting specimens and thus cannot be placed in Pan's sectional classification (Acta Phytotax. Sin. 25: 264-293. 1987). Using only vegetative or fruit characters, it cannot be placed definitively in Oreocharis, since other genera (e.g., Tremacron, Isometrum, and Ancylostemon) are virtually indistinguishable in those characters.