Shrubs, 1.5-2 m tall, spreading to 2.5 m wide; branches arching to spreading. Stems 4-angled but not ancipitous when young, soon terete; internodes 1-5 cm, shorter than leaves. Leaves with petiole 1-2.5 mm; blade elliptic-oblong to ovate-lanceolate or oblong-lanceolate, (2-)2.5-8.5 × 1-3.5 cm, thickly papery, abaxially paler but not glaucous; laminar glands dots and short streaks; adaxial glands absent or rarely sparse; main lateral veins 3- or 4(or 5)-paired, without visible tertiary reticulation; base cuneate, apex apiculate or obtuse to rounded. Inflorescence 1-3(-5)-flowered, from apical node, flat-topped; bracts lanceolate, persistent. Pedicels 2-10 mm. Flowers (3-)5-6.5 cm in diam., shallowly cupped; buds ovoid, apex obtuse. Sepals erect, subequal, ovate to oblong-ovate or oblong-spatulate, 7-10 × 4.5-6.2 mm; laminar glands lines, sometimes interrupted; margin entire or minutely denticulate and sometimes with narrowly hyaline margin, apex acute or apiculate to obtuse. Petals golden yellow, broadly obovate to subcircular, (2-)2.5-3.2 × (1.2-)1.5-3.2 cm, 3-4 × as long as sepals, eglandular, margin entire or eroded-denticulate, apiculus rounded. Stamen fascicles each with 40-45 stamens, longest 1.2-1.5 cm, ca. 2/5 as long as petals. Ovary ovoid, 5-7 × 3-5 mm; styles 4.5-5(-7) mm, 0.7-0.8(-1) × as long as ovary, free, suberect, outcurved near apex. Capsule ovoid to cylindric-ovoid, ca. 2 × 1-1.2 cm. Seeds dark reddish brown, 1-1.2 mm, not or scarcely carinate; testa linear-foveolate. Fl. Apr-Jul, fr. Oct.

Hypericum addingtonii is very similar to some populations of the southern form of H. beanii, differing from them by the more spreading habit, the broader, apically obtuse to rounded leaves, the broader sepals, and the relatively shorter stamens. Its affinities are clearly with the latter species and not, as had been thought, with H. hookerianum.

● Bamboo scrub, thickets on grassy slopes, Tsuga forest edges; 1800-3400 m. NW and W Yunnan (Gongshan, Weishan, Yunlong).