Description from Flora of China
Phylloboea sinensis Oliver, Hooker's Icon. Pl. 18: pl. 1721. 1887; Boea chaffanjonii H. Léveillé; Chlamydoboea sinensis (Oliver) Stapf; C. sinensis f. macra Stapf; C. sinensis f. macrophylla Stapf; Paraboea sinensis f. macra (Stapf) C. Y. Wu ex H. W. Li; P. sinensis f. macrophylla (Stapf) C. Y. Wu ex H. W. Li.
Subshrubs. Stems to 1 m, brown pannose, glabrescent. Leaves opposite, spread along stem; petiole 2-10 cm; leaf blade narrowly elliptic or oblong to ovate or obovate, 5.5-26 X 2-10 cm, papery, adaxially grayish to brown pannose to puberulent, subglabrescent, abaxially brownish pannose, base sometimes oblique, cuneate to subcordate, margin subentire to serrulate, apex acute to acuminate; lateral veins 10-15 on each side of midrib. Cymes axillary, near branch apices; peduncle 2.5-6(-8) cm, brown pannose; bracts 2, suborbicular to broadly ovate, 1-1.5 X 0.8-1.2 cm, outside glandular puberulent to glabrous. Pedicel 5-12 mm. Calyx 5-sect from base or near base; segments oblong-spatulate to flabellate or obovate, 7-15 X 4-7 mm, outside glandular puberulent to glabrous. Corolla blue-purple to purple-red, 1.5-2 cm, outside glabrous; tube 1-1.3 cm; lobes 4-5 X ca. 5 mm. Filaments 6-9 mm, pubescent to glabrous; anthers ca. 4 mm; staminodes 1-3, 0.5-3 mm. Pistil glabrous; ovary 5-6 mm. Style 1.5-5 mm. Capsule spirally twisted, 2.5-5.6 cm, glabrous. Fl. May-Jul, fr. May-Nov.
Paraboea sinensis varies geographically from SW to NE: the leaves gradually diminish in size, their shape varies from elliptic or narrowly elliptic to narrowly oblong, and the number of flowers per inflorescence gradually decreases.
Crevices of rocks or on cliffs in forests; 600-2500 m. SW Guangxi, Guizhou, W Hubei, SE Sichuan, SW and SE Yunnan [Myanmar, Thailand, Vietnam].