A round-headed shrub up to 6 or 7 ft high; young shoots grey or brownish, not downy, unarmed or with a few spines in pairs below the leaf-stalk. Leaves trifoliolate; leaflets scarcely stalked, ovate to rhomboidal, pointed, tapered at the base (the two side ones often more or less obliquely so), sometimes with one or more coarse teeth, but usually entire; 7⁄8 to 13⁄4 in. long, 1⁄2 to 7⁄8 in. wide; dark green above, pale below, smooth and glossy on both surfaces; main-stalk 1⁄2 to 11⁄4 in. long. Flowers dull greenish white, quite small, produced in autumn in a terminal cluster of globose umbels, each on a glabrous slender stalk 1⁄2 to 3⁄4 in. long. Fruits black-purple, roundish, compressed, 3⁄16 in. long, crowned by two recurved free styles.
Native of Yunnan, China; raised by Maurice de Vilmorin from seed sent to him by the Abbeé Monbeig about 1905, but first described from a specimen collected by Kingdon Ward a few years later. It flowers in autumn but I have not noticed that it has any special merit.
A. trifoliatus (L.) Voss Xanthoxylum trifoliatum L. – An allied species, differing in its climbing habit and in the stout, recurved spines that occur scattered on its stems, leaf-stalks and peduncles. It is a common thicket plant in E. Asia, ranging from the E. Himalaya to the Philippines.