蒙椴 meng duan

Trees to 10 m. Bark grayish, exfoliating irregularly; branchlets glabrous; winter buds ovoid, glabrous. Petiole slender, 2-3.5 cm, glabrous; leaf blade broadly ovate or orbicular, 4-6 × 3.5-5.5 cm, abaxially hairy only in axils of veins, adaxially glabrous, lateral veins 4-5 pairs, base slightly cordate or obliquely truncate, margin coarsely serrate, apex acuminate, usually 3-lobed. Cymes 6-12-flowered, 5-8 cm; peduncle glabrous. Pedicel slender, 5-8 mm. Bracts on ca. 10 mm stalk, narrowly oblong, 3.5-6 × 0.6-1 cm, adnate to peduncle for 1/2 of length, both surfaces glabrous, base obtuse, apex obtuse. Sepals lanceolate, 4-5 mm, abaxially subglabrous. Petals 6-7 mm. Stamens as long as sepals; staminodes slightly smaller. Ovary hairy; style glabrous. Fruit obovoid, 5-angled or obscurely angled, 6-8 mm; exocarp thickly leathery, fragile, hairy, indehiscent. Fl. Jul. 2n = 164*.

● Hebei, Henan, W Liaoning, Nei Mongol, Shanxi.