凹萼杨桐 ao e yang tong

Shrubs to 1 m tall. Young branches terete, 2.5-5 mm thick, glabrous; terminal buds long conic, 1.8-2.3 cm, glabrous. Petiole 0.5-1.2 cm, thick, glabrous, adaxially grooved; leaf blade elliptic to rarely broadly obovate, 4.5-12.5 × 2.7-6 cm, thickly leathery, abaxially dark brown glandular punctate and ferruginous when dry, adaxially dark green and shiny, both surfaces glabrous, midvein abaxially elevated and adaxially impressed, secondary veins 17-25 on each side of midvein, abaxially obscure, and adaxially slightly visible, base broadly cuneate to cuneate and decurrent, margin entire, apex abruptly acute, obtuse, or retuse. Flowers axillary, solitary or paired. Pedicel 1-1.6 cm, apically thickened, glabrous; bracteoles caducous. Sepals broadly orbicular to suborbicular, 3-4 × 4-5 mm, thickly leathery, glabrous, margin ciliolate, apex retuse. Petals and stamens not seen. Ovary ovoid, glabrous, 3-loculed with 20-30 ovules per locule; style 7-8 mm, glabrous, apex slightly 2-lobed. Fruit not seen. Fl. Jun-Jul.

● Forests on limestone hills; 1200-1300 m. Guangxi (Napo).