Hypericum subcordatum (R. Keller) N. Robson

Hypericum subcordatum is very closely related to H. monanthemum subsp. monanthemum and resembles a small, delicate form of H. monanthemum var. nigropunctatum with leaves all petiolate and sepals apically acute and entire, characters that do not occur in combination in H. monanthemum itself. Along with the occurrence of both taxa on Emei Shan (Sichuan), where they remain distinct, these differences would appear to justify its separation as a species.

Herbs, perennial, 1-7 cm tall, erect from creeping and rooting base with stems unbranched or branched from upper 1(or 2) nodes. Stems with internodes 2-lined above, terete below, eglandular, slender. Leaves 1-1.5 mm petiolate; blade broadly elliptic or oblong-elliptic to obovate, 1-1.6 × 0.8-1.2 cm; thinly papery, abaxially paler (?or subglaucous); laminar gland dots pale, dense, small, or sometimes a few black, scattered; intramarginal glands black, dense or subirregular; main lateral veins 3-paired, tertiary reticulation rather dense, obscure; base cuneate to truncate or (uppermost) subcordate, margin entire, apex rounded. Inflorescence (1-)3-5-flowered, occasionally with branches from 1(or 2) nodes below, the whole flat-topped or bifurcating to subcylindric; bracts and bracteoles leaflike, margin entire. Flowers (0.8-)1-1.2 cm in diam., stellate; buds ?ellipsoid. Sepals free, erect in ?bud and fruit, oblong-lanceolate to lanceolate, subequal, 3-4.5 × 0.8-1.2 mm; laminar glands black, lines to (distally) dots; marginal glands black, few, sessile or submarginal, all or most distal; margin entire, apex acute; veins 5. Petals ?golden yellow, narrowly elliptic, 4.5-6 × 1-1.5 mm, 1.35-1.5 × as long as sepals; laminar glands black, few, lines to streaks; marginal glands black, few, subapical or absent; margin entire. Stamens 17-20, apparently 3-fascicled, longest 4-5.5 mm, ca. 0.9 × as long as petals. Ovary ellipsoid; styles 3(or 4), 1.7-2 mm, 0.85-1 × as long as ovary, divaricate-ascending. Capsule ovoid to subglobose, 4.8-6 × 3.5-4 mm, 1.5-2 × as long as sepals. Seeds yellow-brown, ca. 0.6 mm; testa finely scalariform. Fl. Jun-Aug, fr. Jul-Sep.

Shaanxi, Sichuan.

● No habitat details known; 1800-2900 m.

Hypericum thomsonii var. subcordatum R. Keller, Bot. Jahrb. Syst. 33: 553. 1904; H. petiolulatum var. subcordatum (R. Keller) H. Léveillé.