Japanese name: テツカエデ（鉄楓） Scientific name:Acer nipponicum
[Overview]
A deciduous tree growing in the mountains, reaching about 15 m in height.
The first-year branches are at first densely covered with brown curly hairs.
The leaves are opposite, pentagonal, 10–15 cm long and 12–20 cm wide, shallowly 5-lobed, rarely 3-lobed.
On the upper surface of the leaf the veins are sunken, giving a wrinkled look.
On the underside, there are reddish-brown curly hairs only in the vein axils and on the veins, or short hairs densely cover the whole surface.
The tips of the leaf lobes extend into tails.
The leaf margin has double serrations.
The leaves have long petioles.
The leaves turn yellow in autumn.
At the tips of flowering branches, slender cylindrical inflorescences 10–20 cm long hang down, bearing as many as 400–1000 flowers; male flowers and bisexual flowers bloom on the same tree (andromonoecious) or on separate plants (androdioecious).
The inflorescence is densely covered with reddish-brown curly hairs.
The flowers are yellowish green, with 5 sepals and 5 petals.
The fruits are about 2.5–3.5 cm long and borne in pairs, each with a propeller-like wing; the wings spread from an acute to an obtuse angle.
