粗壮山香圆 cu zhuang shan xiang yuan

Trees, ca. 8 m tall; branches glabrous, bark red-brown, lenticels impressed. Leaves trifoliolate, rarely 4-foliolate; rachis gray-white when dry, glabrous; petiolule 3-10 mm, adaxially sulcate, with 2 glands present at apex; leaflet blades oblong to oblong-ovate or oblong-obovate, ca. 14 × 6 cm, leathery or thinly leathery, lateral veins 8(-10) pairs, conspicuous abaxially, base obtuse, rarely cuneate, margin serrulate or crenate, apex acuminate. Panicle axillary, 8-15 cm; bracts 2 present at peduncle apex, ca. 6 × 2.5(-4) mm, caducous, glabrous. Pedicel 0.7-4 cm. Sepals nearly ovate or oblong-ovate, ca. 1.75 × 1.5 mm, ciliate, apex obtuse. Petals obovate, ca. 2 × 1.5 mm, ciliate, apex obtuse. Filaments ca. 1.5 mm, glabrous, base broad and acuminate to apex; anthers ca. 0.75 mm. Floral disk undulate. Styles 3, short, free at apex. Fruit not seen. Fl. starting in Jan.

Limestone forests; ca. 900 m. S Yunnan [N Thailand].