Acer pycnanthum ("Hananoki")

Japanese name: ハナノキ （花木）
Scientific name: Acer pycnanthum

[Overview]
A deciduous tree found in mountain wetlands in a limited area, reaching as much as 30 m in height.
The trunk is erect and branches freely from the lower part.
The bark is gray and split vertically.
First- and second-year twigs have distinct ridges.
The leaves are opposite, broadly ovate, 2.5–8 cm long and 2–10 cm wide, shallowly palmately 3-lobed.
The leaves have 3 palmate veins and coarse double serrations along the margin.
The leaves are almost hairless on both sides, and the underside is tinged powdery white.
The petiole is 1.5–8 cm long, as long as 0.5–1.3 times the length of the leaf, and is often tinged red.
The leaves turn a vivid red in autumn.
The plant is dioecious.
The flowers open before the leaves emerge and are borne in bundles of 3–6 from the leaf axils of the previous year's twigs.
The flowers are crimson and very conspicuous, with 5 sepals and 5 petals, and the anthers of the stamens are blackish purple.
The fruits are 2.5 cm long and borne in pairs, each with a propeller-like wing, spreading at a right to acute angle.
When the fruits ripen, the fruit stalks lengthen to 6–7 cm and the entire infructescence falls.

[Cultivation]
Propagate from seed or by cuttings.
It prefers a well-drained place in partial shade to full sun.
Partial shade is better, especially while the tree is young.
In shade, the autumn color develops poorly.
Damage from longhorn beetles and aphids occurs, so kill them as soon as they are found.

[Notes]
The Japanese name comes from the fact that the flowers are very conspicuous.
Its natural habitats and other sites are designated as national natural monuments.
It is the prefectural tree of Aichi.

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