圆叶乌桕 yuan ye wu jiu

Sapium rotundifolium Hemsley, J. Linn. Soc., Bot. 26: 445. 1891; Baccaurea esquirolii H. Léveillé; S. rotundifolium var. obcordatum S. K. Lee.

Trees up to 12 m tall, glabrous; branchlets robust. Leaves alternate; stipules small, glandular, caducous; petioles 3-7 cm, with 1 gland at apex; leaf blade subrotund, 5-11 × 6-12 cm, base rounded to shallowly cordate, margin entire, apex rounded, rarely acute or incised; lateral veins 10-15 pairs. Flowers unisexual, monoecious, densely fascicled in terminal racemes, female in lower part, male in upper part, sometimes male throughout. Male flowers: pedicels cylindric, 1-3 mm; bracts ovate, ca. 2 × 2 mm, margins fimbriate, base bilateral, each with 1 gland; bracteoles narrowly ovate, less than 1 mm; calyx cupular, shallowly 3-lobed; stamens (1 or)2(or 3); filaments shorter; anthers subglobose. Female flowers: pedicels robust, ca. 2 mm; calyx 3-lobed, lobes broadly ovate, ca. 1 mm, margins serrulate; ovary ovate, 3-lobed; styles 3, connate at base; stigma revolute. Capsules subglobose, 8-10 mm in diam. Seeds oblate, ca. 5 mm in diam., with waxy arils. Fl. Apr-Jun, fr. Jul-Oct.

Limestone montane forests; 100-500 m. Guangdong, Guangxi, Guizhou, Hunan, Yunnan [N Vietnam].