Description from Flora of China
Gerardia glutinosa Linnaeus, Sp. Pl. 2: 611. 1753; Adenosma caeruleum R. Brown; A. glutinosum var. caeruleum (R. Brown) P. C. Tsoong; Digitalis sinensis Loureiro; Pterostigma grandiflorum Bentham.
Herbs, 30-100 cm tall. Stems erect, densely villous with eglandular and glandular hairs. Petiole 3-10(-15) mm; leaf blade lanceolate-ovate to broadly ovate, 2-10 X 1-5 cm, abaxially villous and densely yellow punctate glandular, adaxially villous especially along midrib; base cuneate, truncate, or subcordate, margin irregularly serrate and sometimes double serrate, apex acute, midrib concave. Flowers axillary and solitary or in dense racemes apically on stems and branches; bracts small. Pedicel 0.5-1.5 cm, to 2 cm in fruit. Bracteoles linear, 5-9 mm, adnate to base of calyx. Calyx 0.7-1.3 cm; lobes entire, narrowly lanceolate. Corolla purple-red to violet, 0.9-2.8 cm; lower lip 3(or 4)-lobed; upper lip ovate-orbicular, apex truncate to emarginate. Anterior anthers with 1 locule fertile; posterior anthers with both locules fertile. Style gradually widening and narrowly winged. Capsule ovoid, 5-9.5 X 3-6 mm, 2-grooved, apex beaked. Seeds brown to dark brown. Fl. and fr. Jul-Oct.
Mountain slopes, wet places under sparse forests; 300-2000 m. Fujian, Guangxi, Hainan, Jiangxi, Yunnan [Cambodia, India, Indonesia, Laos, Malaysia, Thailand, Vietnam; Australia, Oceania].