Shirasawa Maple

It is a large deciduous bush or a small tree growing up to 8-15 m in height with a trunk up to 50 cm in diameter.

The bark is smooth in young and old trees. The shoots are thin and unrefined.

The leaves are palmate, rounded, 4.5–8 cm long and 6–12 cm wide, with 9–13 (occasionally 7) serrated, shallowly incised lobes; hairless or slightly pubescent initially with white hairs; petiole 3-7 cm long and not pubescent. In the fall, the leaves turn from bright yellow to orange and dark red.

Flowers are 1 cm in diameter, with five dark violet-red sepals , five small whitish petals that will soon fall, and red stamens, flowers collected 10-20 in standing inflorescences, blooms in early spring shortly after the appearance of leaves; this tree is characterized by andromonoetium , on the same plant are male and female flowers, or only male.

The fruit is a double lionfish with nuts 5-10 cm in diameter with 20-25 mm wings, sticking out above the leaves, first bright red, brown when ripe. ^{[3] [4] [5]}

This species can be distinguished from closely related Acer japonicum ( Jap. ハ ウ チ ワ カ エ デ hauchiwakaede ) and Acer sieboldianum ( Jap. コ ハ ウ チ ワ カ エ デ kohauchiwakaede ) by the hairless shoots; from A. sieboldianum also in red rather than yellow. ^{[6] [7]}

Taxonomy

The species of Shirasawa's maples is part of the genus Acer of the Sapindaceae family .

Sometimes the old classification is still used, according to which this species was attributed to Acer japonicum ; some instances in the culture are also mistakenly referred to as Acer japonicum . ^[eight]

Two subspecies recognized : ^[8]

• Acer shirasawanum subsp. shirasawanum
• Acer shirasawanum subsp. tenuifolium

Synonyms include Acer japonicum var. microphyllum Siesmayer and Acer japonicum subsp. shirasawanum . ^[9]

It is grown as a decorative tree in the gardens because of its foliage and autumn colors, but much less often than the Dane-shaped Maple . Many varieties bred ; light-colored variety 'Aureum' is very widespread, found in culture much more often than the main species; propagated by vaccination on more winter-hardy and fast-growing species of maple, mainly on Acer palmatum and Acer japonicum . ^[eight]

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  Leaves and unripe fruits

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  General view of the tree

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  Variety 'Aureum', autumn foliage

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  Variety 'Aureum' in arboretum Robert Lenoir Rondo ( Belgium )

• Rare and Unusual Japanese Maples