4. Gmelina arborea Roxburgh, Pl. Coromandel. 3: 41. 1815.
云南石梓 yun nan shi zi
Trees ca. 15 m tall; bark grayish brown; branchlets, petioles, and inflorescences densely yellow-brown tomentose. Branchlets slightly 4-angled when young, becoming terete, lenticellate, leaf scars prominent. Petiole terete, 3.5-10 cm; leaf blade broadly ovate, 8-19 X 4.5-15 cm, thickly papery, base broadly cuneate to subcordate, apex acuminate; veins 3-5 pairs, abaxially prominent. Inflorescences terminal, narrow thyrses; peduncle 15-30 cm. Calyx 3-5 mm, with several black discoid gland patches; teeth 5, sharply triangular. Corolla yellow, 3-4 cm, 2-lipped, sparsely glandular; lower lip 3-lobed, outside yellowish brown puberulent, inside glabrous; upper lip entire or slightly 2-cleft. Ovary glabrous, glandular. Stigma unequally 2-cleft. Drupes yellow when ripe and black when dry, ellipsoid to obovoid-ellipsoid, 1.5-2 cm. Fl. Apr-May, fr. May-Jul.
Open forests along roadsides and near farm houses; below 1500 m. S Yunnan [Bangladesh, Bhutan, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam]
Allied to Gmelina asiatica but differs in having erect inflorescences and larger leaves.