Alnus hirsuta var. hirsuta ("Keyamahannoki")

Japanese name: ケヤマハンノキ （毛山榛木）
Scientific name: Alnus hirsuta var. hirsuta

[Overview]
A deciduous tree 15–20 m tall, growing from dry places such as sunny landslide areas and ridges in the mountains to moist places along riverbeds and riverbanks.
The bark is grayish white to grayish brown and smooth, with horizontally elongated lenticels, and it is often mottled with whitish patches because of lichens.
The twigs, the undersides of the leaves, and the inflorescences are densely covered with brown, velvety soft hairs.
Leaves are simple and alternate, triangular-rounded, 6–14 cm long and 4–13 cm wide, somewhat thick, with 6–8 pairs of lateral veins.
The leaf margins have large, mountain-shaped double serration.
The wrinkling of the veins is somewhat conspicuous on the upper leaf surface.
The petiole is 1.5–3 cm long.
There are male and female flowers, which bloom before the leaves unfold.
The male flowers grow on catkins hanging down in groups of 2–4 from the branch tips or from the leaf axils near the tips.
The male catkins have stalks.
The male flowers are small and borne in threes beside scale-like bracts; the perianth is 4-lobed and there are 4 stamens.
The female flowers grow on cone-like inflorescences, 3–5 at a time, in the leaf axils below the male catkins.
The female flowers have no perianth.
The fruiting spike is elliptical and cone-like, 1.5–2.5 cm long and about 1 cm wide, with the fruits attached to the inner surface of the scales.
The fruit is a flattened nut with narrow wings, and the style remains at the tip.

[Uses]
The bark and fruiting spikes are used medicinally.

[Cultivation]
Propagate from seed or by cuttings.
Thanks to symbiotic microbes, it grows well even in poor soil.
Plant it in a sunny place.
There are no particular pests or diseases.

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