Description from Flora of China
Strobocalyx sylvatica (Dunn) H. Robinson et al.
Scandent shrubs. Stems terete, striate, densely reddish brown pubescent. Petiole 5-10 mm, densely reddish brown pubescent; leaf blade ovate or oblong, 6-13 × 2-5.5 cm, papery, both surfaces densely pubescent along veins and concavely glandular, lateral veins 7- or 8-paired, adaxially prominent, veinlets reticulate, base obliquely rounded, margin entire or sometimes sinuately denticulate, apex shortly acute or acuminate, or obtuse. Synflorescences terminal, panicles broad. Capitula many, 7-12 mm in diam.; peduncles 5-15 mm; bracteoles 1 or 2, ovate-lanceolate. Involucre hemispheric, 3-5 mm; phyllaries ca. 4-seriate, black in center when dry, ovate or ovate-lanceolate, densely brownish pubescent, apex acute, outer short, ovate. Receptacle flat, foveolate. Florets ca. 10, 3-4 × as long as involucre; corolla purple or pink-purple, tubular, ca. 7 mm, lobes lanceolate, glandular. Immature achenes cylindric, ?4- or 5-ribbed, glabrous or sparsely puberulent. Pappus 2-seriate, white; outer setae very short; inner setae subequal to corolla, scabrid. Fl. and fr. Sep-Mar.
● Open forests in valleys, thickets on roadsides; 500-1900 m. Guangxi, Yunnan.