Acer shirasawanum

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids II
Ordo: Sapindales

Familia: Sapindaceae
Subfamilia: Hippocastanoideae
Tribus: Acereae
Genus: Acer
Species: Acer shirasawanum
Name

Acer shirasawanum Koidz., J. Coll. Sci. Imp. Univ. Tokyo 32(1): 38 (1911).
References
Additional references

Ohwi, J. 1965. Flora of Japan (translated by F.G. Meyer & E.M. Walker). 1067 pp. Smithsonian Institution, Washington, D.C. BHL Reference page.
Murray, A.E., 1970. A monograph of the Aceraceae. Unpublished Ph.D. dissertation, The Pennsylvania State University. Reference page.
Iwatsuki, K. et al. (eds.) 1993–. Flora of Japan. Vols. 1–4. Tokyo: Kodansha. Reference page.
Gelderen, D.M. van, Jong, P.C.de & Oterdoom, H.J. 1994. Maples of the world. Timber Press, Portland, Or., 458 pp. ISBN 0-88192-000-2. Reference page.
Govaerts, R.H.A. 1995. World Checklist of Seed Plants 1(1, 2). 483, 529 pp. MIM, Deurne. ISBN 90-341-0852-X (issue 1) ISBN 90-341-0853-8 (issue 2). Reference page.

Links

USDA, ARS, Germplasm Resources Information Network. Acer shirasawanum in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 08-Apr-12.
Govaerts, R. et al. 2020. Acer shirasawanum in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2020 January 8. Reference page.
International Plant Names Index. 2020. Acer shirasawanum. Published online. Accessed: 8 January 2020.

Vernacular names
English: Shirasawa's Maple
日本語: オオイタヤメイゲツ
polski: Klon Shirasawy

Acer shirasawanum, the Shirasawa maple or fullmoon maple (Japanese: オオイタヤメイゲツ, romanized: ooitayameigetsu), is a species of maple native to Japan, on central and southern Honshū (Fukushima Prefecture southwards), Shikoku, and Kyūshū.[3]

Description

This species grows as a deciduous large shrub or small tree growing to 8–15 m tall with a trunk up to 50 cm diameter. The bark is smooth on both young and old trees. The shoots are slender, and hairless. The leaves are rounded, 4.5–8 cm long and 6–12 cm broad, palmately veined and lobed, with 9–13 (rarely 7) serrate shallowly incised lobes; they are hairless, or thinly hairy at first with white hairs; the petiole is 3–7 cm long and hairless. In autumn, the leaves turn bright gold or orange to dark red. The flowers are 1 cm diameter, with five dark purplish-red sepals, five small whitish petals (soon lost), and red stamens; they are andromonoecious, with inflorescences containing flowers with either both sexes, or just male, and are produced 10–20 together in erect terminal corymbs in early spring soon after the leaves appear. The fruit is a paired samara with the nutlets 5–10 mm diameter with a 20–25 mm wing, erect above the leaves, bright red maturing brown.[3][4][5]
Taxonomy

Acer shirasawanum is named after Japanese botanist Homi Shirasawa.

It can be distinguished from its close relatives Acer japonicum and Acer sieboldianum by its hairless shoots; from A. sieboldianum also by its red, not yellow, flowers.[6]

Some authorities, especially in horticulture, still use the older classification including the species in A. japonicum; many specimens in cultivation also remain mislabelled as A. japonicum.[7]

Two subspecies are accepted:[7]

Acer shirasawanum subsp. shirasawanum
Acer shirasawanum subsp. tenuifolium

Cultivation and uses

It is grown as an ornamental tree in gardens for its foliage and autumn colour, but is seen far less commonly than Acer palmatum (Japanese maple). A number of cultivars have been selected; the lighter-coloured A. shirasawanum cultivar 'Aureum' is very widely grown, much more common in cultivation than the main species, and has gained the Royal Horticultural Society's Award of Garden Merit.[8]

It is propagated by grafting onto more hardy and fast-growing Acer species, in particular A. palmatum and A. japonicum.[7]

References

The Plant List, Acer shirasawanum Koidz.
Delendick, T. J. (1984). Reconsideration of Two Infraspecific Taxa of the Fullmoon Maple, Acer japonicum (Aceraceae). Brittonia 36 (1): 49–58 doi=10.2307/2806291
Okayama science university: Acer shirasawanum (in Japanese; google translation)
Okayama science university: Acer shirasawanum flowers Archived 2012-02-14 at the Wayback Machine (in Japanese; google translation)
Rushforth, K. (1999). Trees of Britain and Europe. Collins ISBN 0-00-220013-9.
Kanagawa Prefecture trees and shrubs: Acer sieboldianum Archived 2009-10-24 at WebCite (in Japanese; google translation). Archived 2009-10-24.
Maples for Gardens: A Color Encyclopedia by C.J. van Gelderen & D.M. van Gelderen, 1999
"Acer shirasawanum 'Aureum'". RHS. Retrieved 27 February 2020.