Roettlera yunnanensis Franchet, Bull. Mus. Hist. Nat. (Paris) 5: 250. 1899; R. yunnanensis f. cleistogama Diels.

Stems 3-26(-48) cm, densely puberulent to glabrescent. Leaves opposite; petiole 0.2-14 cm; leaf blade narrowly ovate to ovate, oblong, or obovate, 1-14 X 1-10 cm, herbaceous, adaxially appressed puberulent, eglandular, abaxially puberulent along veins, eglandular, base oblique, broadly cuneate to cordate, margin crenate to crenulate or nearly entire, apex acute to rounded; lateral veins 5 or 6 on each side of midrib. Cymes 1-15-flowered; peduncle 1-12 cm, sparsely glandular puberulent; bracts free, ovate to orbicular, often leaflike, 0.2-2 cm, glabrous to puberulent, yellow glandular, margin crenate to entire. Pedicel 4-10 mm. Calyx slightly zygomorphic, 3-6 mm; limb indistinctly 2-lipped; tube 2-4 mm; adaxial lip 3-lobed, depressed trapeziform, ca. 2 mm, lobes triangular, 1-2 X ca. 1.2 mm; abaxial lip 2-lobed, depressed trapeziform, ca. 3 mm, lobes triangular, 1-2 X ca. 2 mm, outside sparsely puberulent, inside glabrous, margin entire. Corolla purple to reddish purple with darker stripes, 2.5-3.5 cm, outside sparsely pubescent, inside glabrous; tube narrowly funnelform, 2-2.8 cm X 4-6 mm; adaxial lip ca. 3.5 mm; abaxial lip ca. 7 mm. Filaments ca. 7 mm, glabrous; anthers ca. 2 mm, sparsely pubescent; staminodes 3, 1.2-5 mm. Pistil 2.3-3.2 cm, glabrous; ovary ca. 8 mm. Capsule 3-4.2 cm. Fl. Jun-Sep, fr. Jul-Oct.

Didymocarpus yunnanensis is very similar to and is probably very closely related to D. punduanus Wallich ex R. Brown. The two species may be conspecific, and the former is retained because we have not seen adequate material of the latter.

Rocks, cliffs in valleys; 1500-3400 m. SW Sichuan, SE Xizang, NW and W Yunnan [NE India].