Description from Flora of China
Shrubs, 0.3-1.2 m tall, branches arching to pendulous, young shoots purplish red. Stems 4-lined when young, soon terete; internodes 1-2.5 cm, shorter than leaves. Leaves with petiole 0.5-1 mm; blade triangular-lanceolate to triangular-ovate, 2-4 × 0.8-2 cm, thickly papery, abaxially ± glaucous; laminar glands streaks (occasionally elongate) and dots; abaxial glands dense; main lateral veins 3- or 4-paired, tertiary reticulation obscure or invisible; base rounded to shallowly cordate, apex acute or more rarely obtuse to rounded. Inflorescence 1(-3)-flowered from apical node; bracts linear or usually leaflike. Pedicels 6-10 mm. Flowers 2-4 cm in diam., deeply cupped; buds ovoid, apex acute to apiculate. Sepals outcurved or spreading, unequal, lanceolate or narrowly elliptic to ovate, 0.8-1.4 cm × 3-5 mm; laminar glands lines interrupted distally, margin entire and purplish in bud and fruit, apex subacute to acuminate or rarely apiculate-obtuse. Petals deep yellow, broadly obovate to subcircular, 1.2-2.2 × 0.8-1.7 cm, 1.1-1.5(-2) × as long as sepals; margin entire, eglandular; apiculus obtuse to rounded. Stamen fascicles each with ca. 60 stamens, longest 1-1.2 cm, 0.35-0.7 × as long as petals. Ovary ± broadly ovoid, 6-8 × 4.5-6 mm; styles 3-4 mm, ca. 0.5 × as long as ovary, free, outcurved near apex. Capsule ovoid-conic to broadly ovoid, (1.2-)1.4-1.7 cm × 8-10 mm. Seeds dark reddish brown, 0.8-1 mm, not or scarcely carinate; testa linear-foveolate. Fl. May-Jun, fr. Jul-Sep.
The distribution of Hypericum curvisepalum largely coincides with that of H. lancasteri, from which it has probably been derived. Indeed, these species may even occur in the same area and appear to have similar habitat requirements. The characters that distinguish them, however, are maintained in cultivation, so that their specific status would not appear to be in doubt.
● Dry or rocky hillsides and open woodlands; 1800-3000 m. SW Guizhou (Pu’an), S Sichuan, C, N, and W Yunnan.