Description from Flora of China
Hypericum biondii R. Keller, p.p.; H. chinense Linnaeus var. minutum R. Keller; H. macrosepalum Rehder; H. obtusifolium R. Keller; H. pedunculatum R. Keller.
Herbs, perennial, (0.17-)0.3-0.55 m tall, erect or sometimes ascending at base; stems few to numerous, simple or usually branched below inflorescence or throughout. Stems incompletely 4-lined or 2-lined when young, nearly always soon becoming terete. Leaves sessile; blade broadly oblong or oblong-ovate to narrowly oblong or oblong-lanceolate (reduced in size down stem), 2-6.5(-8) × 1-3.2 cm, thickly papery, abaxially rather paler but not glaucous; laminar glands dense, unequal dots or short streaks; intramarginal glands dense; main lateral veins 4-6-paired, with densely reticulate tertiary venation not or scarcely prominent abaxially; base cordate-amplexicaul, apex rounded to shallowly retuse. Inflorescence 1-7-flowered from 1-3 nodes, flat-topped, sometimes with flowering branches from up to 5 nodes below, the whole then narrowly pyramidal to cylindric; bracts and bracteoles leaflike, ovate, entire, persistent. Flowers 2-4 cm in diam., stellate; buds nar- rowly ovoid to cylindric, apex obtuse to rounded. Sepals free or basally united, erect in bud, spreading to deflexed in fruit, subequal to unequal or rarely leaflike, narrowly or broadly oblong or elliptic to lanceolate or ovate-lanceolate or triangular-lanceolate, 8-10 × 2-4 mm, sometimes enlarging to 1.5 cm × 6.5(-8) mm in fruit; laminar glands rather sparse dots, distal and submarginal; marginal glands dense, small, margin undulate, apex rounded to obtuse or rarely short mucronate; veins (5-)7-9. Petals bright yellow, oblong-oblanceolate, 1.2-1.8 cm × 4-8 mm, 1.5-1.8 × as long as sepals; laminar glands lines, sometimes interrupted distally; marginal glands absent; margin entire; apiculus absent. Stamen fascicles each with 15-30 stamens, longest 1-2.4 cm, 0.85-1 × as long as petals. Ovary ovoid; styles 4.5-13 mm, 1-1.8 × as long as ovary, 0.5-0.9 united or appressed (when short); stigmas narrowly capitate. Capsule broadly to narrowly ovoid or subcylindric, 1.4-2.1 × (0.5-)0.7-1.4 cm, 1-2.1 × as long as sepals, apex obtuse. Seeds dark reddish brown to grayish brown, 1.3-1.5 mm, shallowly carinate, without terminal expansion; testa densely linear-reticulate. Fl. Jun-Aug, fr. Jul-Oct.
Hypericum przewalskii is closely related to H. ascyron, differing from it essentially by the obtuse to retuse leaf apex and usually 2-lined mature stem internodes. Hypericum macrosepalum seems to be aberrant in having more persistently 4-angled internodes, but is otherwise typical of forms with leaflike sepals in fruit. Hypericum pedunculatum typically has longer, narrower leaves and is more branched than typical H. przewalskii, but there is a complete intergradation between it and the typical form.
● Mountain slopes, river bank thickets, meadows, roadsides; 2100-3400(-4000) m. Gansu, Henan, W Hubei, Qinghai, Shaanxi, Sichuan, N Yunnan.