Description from Flora of China
Shrubs, 0.6-2 m tall; branches erect to ascending. Stems 4-angled and ancipitous when young, eventually terete; internodes 1-5 cm, shorter than to exceeding leaves. Leaves with broad petiole 0.5-1(-1.5) mm; blade oblong or elliptic-oblong to narrowly elliptic, sometimes oblanceolate toward stem base, 1.8-4.2(-6) × 0.6-1.5(-2) cm, thickly papery to subleathery, abaxially ± densely glaucous; laminar glands small dots and sometimes short streaks; abaxial glands rather dense to sparse; main lateral veins 1- or 2-paired, the upper forming distinct often ± straight intramarginal vein, tertiary reticulation very obscure or not visible; base cuneate, apex obtuse or more rarely subacute to rounded-apiculate or rounded. Inflorescence 1-3(-6)-flowered, from apical node, nearly flat-topped; bracts lanceolate to leaflike, persistent. Pedicels 0.7-1.7 cm. Flowers 3-5 cm in diam., stellate; buds ovoid, apex acute to subapiculate. Sepals ± outcurved, ovate to narrowly lanceolate, subequal, (5-)6-9(-11) × 3-4(-6) mm; laminar glands lines, sometimes interrupted, margin subentire or minutely and ± irregularly denticulate (especially toward apex), apex acute to subacuminate. Petals deep yellow, sometimes tinged red, obovate, 1.6-2.5 × 1-1.5 cm, 2.5-3 × as long as sepals; margin entire or often minutely glandular-denticulate, especially around apiculus; apiculus subacute to obtuse. Stamen fascicles each with 40-65 stamens, longest (1-)1.5-1.8 cm, 0.75-0.85 × as long as petals. Ovary narrowly ovoid-conic, 5-7 × 3.5-4.5 mm; styles (3-)4-6(-8) mm, ca. as long as ovary or slightly longer, free, suberect, outcurved near apex. Capsule ovoid to narrowly ovoid-conic, 0.9-1.5 cm × 8-10 mm, turning bright red when maturing in open habitats. Seeds dark orange- to reddish brown, 1-1.1 mm, narrowly carinate with terminal expansion; testa linear-foveolate. Fl. May-Jul, fr. Aug-Sep.
Its usually oblong or elliptic, apically ± rounded leaves, glaucous abaxially and with a conspicuous intramarginal vein, enable Hypericum acmosepalum to be recognized even when sterile.
● Forest glades, roadside banks, scrubby hillsides, open streamsides; 900-2700 m. NW and W Guangxi, NE and SW Guizhou, SW Sichuan, Yunnan.