Hypericum seniawinii Maxim.

Hypericum seniawinii and the very closely related H. hengshanense appear to be southeastern derivatives of the H. pedunculatum form of H. przewalskii. Hypericum seniawinii differs from H. hengshanense in lacking glandular auricles on the leaves but sometimes bears these on the bracts and bracteoles, and the leaves are usually relatively narrower than in that species; but in both species the leaves become markedly narrower toward the south of their respective ranges. Hypericum lianzhouense and H. lianzhouense var. guangdongense fall within the range of variation and area of distribution of H. seniawinii in most respects, but the relative style length cited for the species (ca. 4 × as long as the ovary) is longer than that obtained from previous observations.

Herbs, perennial, (0.15-)0.3-0.6(-1.15) m tall, erect from creeping, rooting and sometimes branching base; stems usually single, sometimes branched above, branches virgate to curved-ascending. Stems terete, eglandular. Leaves sessile or with broad "petiole" to 1 mm; blade oblong to oblong-lanceolate, (1.5-)2-5.2 cm × 5-13(-16) mm, thickly papery, abaxially paler and rarely minutely papillose (Guangdong), not or ± densely glaucous; laminar gland dots pale, dense, rather large; intramarginal glands all black or the occasional one pale, dense; main lateral veins 3(or 4)-paired, tertiary reticulation dense; base subcordate-amplexicaul to broadly or narrowly cuneate, apex obtuse to rounded. Inflorescence 5-50-flowered, from 1-3 nodes, dense, nearly flat-topped to broadly pyramidal; flowering branches from up to 9 nodes below (often with a gap of sterile nodes), the whole then cylindric; bracts and bracteoles ovate to linear-lanceolate, entire or occasionally with basal glandular cilia or rudimentary auricles. Flowers 0.9-1.5(to ca. 2) cm in diam., conic to stellate or recurved; buds ellipsoid, apex acute to obtuse. Sepals free, erect, subequal to equal, oblong-lanceolate to linear-lanceolate, 2.5-5(-7) × 1-2 mm; laminar glands pale, lines to streaks; marginal glands all black or rarely a few pale, in regular or interrupted row, sessile or slightly prominent, margin entire or subentire, apex acute; veins (3 or)5. Petals ?bright yellow, narrowly oblong to narrowly oblanceolate-elliptic, 7-10(-14) × 2-3 mm, 2-3 × as long as sepals; laminar glands pale, streaks to dots, or absent; marginal glands black, distal, sessile or more proximal immersed; margin subentire. Stamens 24 to ca. 55, apparently 3-fascicled, longest 5-12 mm, slightly shorter than petals. Ovary narrowly ovoid, 1.5-3 × 0.7-1.3 mm; styles 3, (2.5-)4-10(-12.5) mm, 1.5-3(-4) × as long as ovary, divaricate-incurved. Capsule ovoid, 5-6 × 4-5 mm, exceeding sepals. Seeds 0.5-0.8 mm; testa finely foveolate. Fl. (Jun-)Jul-Sep, fr. Aug-Nov.

Anhui, Fujian, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangxi, Sichuan, Zhejiang [N Vietnam].

Slopes, grasslands, roadsides; (100-)500-1600(-2000) m.

Hypericum lateriflorum H. Léveillé; H. lianzhouense L. H. Wu & D. P. Yang; H. lianzhouense subsp. guangdongense L. H. Wu & D. P. Yang.