Hypericum sampsonii (Nomenclature)
Perennial herb, 0.2-0.8 m tall, erect from decumbent rooting base, with stems single or few, branched above or almost throughout, with branches curved-ascending. Stems terete, eglandular; internodes 20-85 mm, exceeding leaves or shorter than them. Leaves in perfoliate pairs; lamina (20-)25-70(-80) ´ (7)10-35 mm, broadly or narrowly lanceolate to oblong or oblanceolate, paler beneath, not glaucous, plane, chartaceous; apex obtuse to rounded, margin entire, common base somewhat expanded, rounded; venation: 4-5 pairs of main laterals from lower half to third of midrib, branching and uniting near margin, with tertiary reticulation not prominent, rather lax; laminar glands all pale to mostly black, punctiform, dense; intramarginal glands black, dense. Inflorescence c. 20-40-flowered from 2 nodes, corymbiform, with flowering branches from up to 6 nodes below and uppermost pair sometimes overtopping terminal inflorescence, the whole corymbiform to subpyramidal or cylindric; pedicels 2-3 mm; uppermost bract pair and bracteoles linear-lanceolate to linear, deciduous, other bracts foliar, persistent, all entire. Flowers 6-10(-15) mm in diam., substellate with cupuliform base; buds ovoid, obtuse. Sepals 5, 3-7(-10) ´ 1-3 mm, free, unequal, erect in bud and fruit, oblong to oblong-spathulate or linear-oblong, rounded, entire; veins 5(3), branching outward distally; laminar glands ± numerous, pale and rarely black, striiform to punctiform; intramarginal glands irregular, black, rarely absent. Petals 5, bright yellow, not red-tinged in bud, 4-8(-13) ´ 1.5-4(-7) mm, elliptic-oblong, rounded, margin entire or subentire; laminar glands pale (very rarely a few black), shortly striiform to punctiform; marginal glands black, sessile to subsessile. Stamens 30-42, longest (2-)3-4 mm, c. 0.5 ´ petals; anther gland black. Ovary 3-locular, 2.5-3 ´ 1.5-2 mm, ovoid to narrowly pyramidal; styles 3, c. 2 mm, c. 0.65 ´ ovary, free, outcurving; stigmas broadly capitate. Capsule 6-9 ´ 4-5 mm, broadly ovoid to broadly or narrowly ovoid-pyramidal, exceeding sepals; valves with scattered ovoid to ± elongate amber vesicular glands. Seeds orange-brown, c. 1 mm long, cylindric, not carinate or appendiculate; testa finely ribbed-scalariform.
Thickets, streamsides, grassy places, roadsides and cultivated margins; 110-1700 m.
China (eastern Gansu to Jiangsu southward, including Hong Kong), Taiwan, Japan (Kyushu, S. Honshu), Vietnam (extreme N.), Myanmar (Shan States).
Hance and apparently all succeeding authors placed this species in Sect. 13. Drosocarpium, on the basis of its gland-dotted capsule valves, despite its wide morphological and geographical differences from all species in that mainly south-east European section. Disregarding its specialisations, H. sampsonii is morphologically nearest to H. przewalskii (sect. Roscyna); the perfoliate leaf pairs and glandular-punctate capsule valves would be anomalous in sect. Hypericum. It seems appropriate, therefore, to place this species and its very close relative, H. assamicum, in a separate section directly derived from H. przewalskii.