A small tree up to 50 ft high, with smooth, polished, glabrous young branchlets. Leaves ovate to wide-ovate, acuminate to caudate at the apex, 13⁄4 to 31⁄4 in. long, 13⁄8 to 23⁄8 in. wide (larger on strong shoots), coarsely and irregularly dentate, sometimes with one or two short lobes on each side, papery in texture, glabrous, upper surface rich deep green, lower surface light green. Female flowers densely crowded in a cylindrical spike about 3⁄8 in. long, which is bare of flowers along a narrow strip down one side. Fruits said to be black.
A native of Japan in the small islands of Hachijo and Miyake of the Izu-No- Shichito chain, south of the main island. It is closely allied to M. australis, but seems distinct enough to rank as a species, differing in the glabrous, coarsely dentate leaves and the peculiarity of the female inflorescence noted above. According to Wilson, who collected it on Hachijo in April 1917 (No. 8373), it grows wild there and is also much cultivated for feeding silkworms. A tree at Kew, whose leaves usually colour bright yellow in the autumn, was almost certainly raised from seeds collected by Wilson.