Acer carpinifolium (hornbeam maple; Japanese: ãÂÂãÂÂãªãÂÂã Chidorinoki "zigzag tree") is a species of maple native to Japan, on the islands of Honshà «, Kyà «shà «, and Shikoku, where it grows in woodlands and alongside streams in mountainous areas.
It is a small deciduous tree growing to 10âÂÂ15 m tall, with smooth, dark greenish-grey to grey-brown bark. The leaves are 7âÂÂ15 cm long and 3âÂÂ6 cm broad, simple, unlobed, and pinnately veined with 18âÂÂ24 pairs of veins and a serrated margin. They resemble leaves of hornbeams more than they do other maples, except for being arranged in opposite pairs, and in the very small basal pair of veins being palmately arranged as in other maples. The flowers are 1 cm diameter, greenish yellow, produced in pendulous racemes 5âÂÂ12 cm long in spring as the new leaves open; they are dioecious, with male and female flowers on separate trees. The fruit is a samara of two seeds each with a 2âÂÂ3 cm long wing.
It is occasionally cultivated as an ornamental plant in temperate regions, mainly as a botanical curiosity to demonstrate the wide range of leaf morphology in the genus Acer, but also for its bright yellow autumn colour. Both the scientific and common names derive from the superficial resemblance of its leaves to those of the genus Carpinus (hornbeams).