Hypericum japonicum

Prostrate or procumbent, often mat-forming perennial herb, rarely more than c. 8 cm high, rooting from the lower nodes; stems 4-ridged, internodes often shorter than leaves. Leaves elliptic to obovate, 2–10 mm long, 2.5–5 mm wide, spreading from stems, margins not recurved (but often undulate). Flowers solitary and terminal or in reduced cymes; sepals ± equal, elliptic, 1.5–5 mm long, not black-dotted; petals shortly exceeding sepals, yellow, not black-dotted; stamens 10–30, c. half as long as petals, free; styles 3. Capsule ovoid to ellipsoid, plump, slightly shorter than or equal to sepals; seeds ovoid to ellipsoid, 0.7 mm long, smooth or minutely trabeculate. Flowers mainly Oct.–Mar.