Acer rufinerve

Redvein maple or Honshū maple is in the soapberry or Sapindaceae family and is native to mountain forests on the main islands of Honshū, Kyūshū and Shikoku in Japan. It is a small tree, reaching up to 15 m in height. The name reflects the reddish down on the veins.

It is in the snakebark group of maples identified by: Snakeskin-like bark; buds on stocks, 1 pair of scales; flowers (and double samaras) on pendulous racemes. It is related to red snakebark maple (Acer capillipes) with which it often occurs.

• Leaves are deciduous, simple, opposite, 8–16 cm long and 6–16 across, 3-lobed (occasionally 5), double serrated; upper surface is matt to sub-shiny dark green, paler below with small tufts of rusty hair on the veins when young; petiole is greenish, 3–5 cm long; autumn colour is bright orange or red.
• Species is dioecious; flowers are produced in racemes 10 cm long, 8–10 mm in diameter, with 5 yellowish sepals and petals.
• The fruit is a paired samara 2–3 cm long, with rounded nutlets, spreading obtusely, mounted in strings, maturing in late summer.