Hypericum taihezanense Sasaki ex S. Suzuki

In Fl. Taiwan (2: 640. 1976), Hypericum taihezanense was included in H. pseudopetiolatum R. Keller because its variation fell within the range of variation of that species in Japan. The work of T. Kato on the H. pseudopetiolatum group, however, has clarified the situation in Japan, and the Taiwanese population, with its entire sepals and broadly ovoid to subglobose capsule, seems to be a distinct southern species related to the Japanese H. kiusianum Koidzumi.

Herbs, perennial, 15-40 cm tall, ascending from creeping and rooting base; stems ± cespitose, branched above. Stems terete, eglandular. Leaves sessile or with petiole to 0.7 mm; blade triangular-lanceolate or ovate to obovate, 0.4-1.7(-2) cm × 2-6(-10) mm; ± thinly papery, abaxially paler or glaucous; laminar gland dots pale only, dense, varying in size; intramarginal glands black, rather dense; main lateral veins 3- or 4-paired, tertiary reticulation rather dense, often marked; base cordate-amplexicaul to cuneate, margin entire and plane, apex rounded. Inflorescence 1- to ca. 10-flowered, from 1 or 2 nodes; flowering branches from up to 2 nodes below, the whole laxly flat-topped to cylindric; bracts and bracteoles reduced leaflike, margin entire. Flowers 5-10 mm in diam., concave; buds ellipsoid, apex obtuse. Sepals free, erect in bud, ascending in fruit, subequal to unequal, lanceolate to narrowly oblong or linear, 3-5.5 × 1-1.5 mm; laminar glands all pale, streaks and dots; intramarginal glands black or those toward base pale, regular, ± dense; margin entire, apex obtuse to rounded; veins 3-5. Petals mid-yellow, obovate-oblong to narrowly obovate, (3-)5-6(-8) × (1-)2-3.5 mm, (0.7-)1.2-2 × as long as sepals; laminar glands pale, few, dots or streaks, distal, or absent; marginal glands black, sessile or on cilia; margin with sessile or stalked glands near apex or around upper half (sometimes few). Stamens ca. 30, apparently 3-fascicled, longest ca. 4 mm, 0.8-0.9 × as long as petals. Ovary broadly ovoid; styles 3, ca. 1.5 mm, ca. 0.5 × as long as ovary, divergent to ascending. Capsule broadly ovoid to subglobose, 4-5(-6.5) × 4-4.5 mm, 0.8-1.2 × as long as sepals. Seeds dark brown, 0.5-0.6 mm; testa finely scalariform-foveolate. Fl. Apr-Jul(-Aug), fr. (Jun-)Jul-Sep.

Guangdong, Taiwan (except extreme south) [Indonesia (Sumatra), Malaysia (Sabah), Philippines (Luzon)].

Forest margins, mountain slopes, grassy places, open ground, roadsides; 1000-3000 m.

Hypericum pseudopetiolatum R. Keller var. taihezanense (Sasaki ex S. Suzuki) Y. Kimura.