Description from Flora of China
Didymocarpus speluncae Handel-Mazzetti, Symb. Sin. 7: 1377. 1936; D. minutus Handel-Mazzetti (1936), not Kraenzlin (1927).
Perennials, stemless. Rhizome internodes inconspicuous. Leaves basal, opposite; petiole 2-10 X 1-2 mm; leaf blade narrowly elliptic to elliptic, 1-2.2 cm X 5-9 mm, papery, densely pubescent, eglandular, base cuneate, margin entire, apex acute to rounded; lateral veins 2 or 3 on each side of midrib, inconspicuous. Cymes 1-flowered; peduncle 1.1-2.2 cm, densely spreading villous; bract 1, narrowly linear, ca. 1 X 0.3 mm, pubescent, margin entire, apex acute. Pedicel ca. 4 mm, puberulent. Calyx 5-sect from base; segments equal, lanceolate-linear, ca. 2 X 0.5 mm, outside densely villous, inside puberulent near apex, margin often 1-denticulate apically, apex acute. Corolla purple, ca. 1.2 cm, outside sparsely pubescent, inside nearly glabrous; tube cylindric, ca. 6 X 2 mm; adaxial lip ca. 4 mm; abaxial lip ca. 6 mm. Filaments ca. 1.6 mm, glabrous; anthers fused by entire adaxial surfaces, ca. 1.2 mm, glabrous; staminode 1, ca. 0.3 mm. Pistil ca. 3.8 mm, puberulent; ovary ca. 1.7 mm. Stigma oblate, ca. 0.4 mm, undivided. Capsule erect, ca. 7 mm. Fl. Apr.
After publication of the family treatment for the Flora of China,
this was treated as Primulina speluncae (Handel-Mazzetti) Mich. Möller & A. Weber (Taxon 60: 784. 2011).
* Hilly regions; ca. 800 m. NE Yunnan.