''Acer micranthum'', the small-leaved maple, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Sapindaceae in the

snakebark maple Snakebark maples are maples belonging to the taxonomic section ''Acer'' sect. ''Macrantha''. The section includes 18–21 species, and is restricted to eastern Asia (the eastern Himalaya east to Japan) with the exception of one species in easte ...

group,

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, on

Honshū , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separa ...

Kyūshū is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...

and

Shikoku is the smallest of the four main islands of Japan. It is long and between wide. It has a population of 3.8 million (, 3.1%). It is south of Honshu and northeast of Kyushu. Shikoku's ancient names include ''Iyo-no-futana-shima'' (), '' ...

. Its

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

name is the .Kobe city
''Acer micranthum''
(in Japanese

Kanagawa Prefecture trees and shrubs

(in Japanese

2009-10-24.Okayama science university

(in Japanese

Kanon tree book

(in Japanese

Maple World

Maple World

It is a small, sometimes shrubby tree growing tall, with slender, arching branches. The bark is smooth and striped at first, becoming rough and dull grey on mature trees. The shoots and winter buds are dark purple-red. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are 4–10 cm long and 2–8 cm broad, palmately lobed, with five deeply toothed lobes with long acuminate tips and double-serrated margins, and with distinctive tufts of orange-red hairs in the main vein axils at the base of the leaf; the petiole is 2–5 cm long. The leaves emerge red in spring and turn shades of yellow, orange and red in autumn. The flowers are produced in early summer in

raceme A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the s ...

s 4–10 cm long, each flower 4 mm diameter, with five yellow to greenish-yellow sepals and petals; it is

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

, with male and female flowers on separate trees. The fruit is a paired

samara Samara ( rus, Сама́ра, p=sɐˈmarə), known from 1935 to 1991 as Kuybyshev (; ), is the largest city and administrative centre of Samara Oblast. The city is located at the confluence of the Volga and the Samara (Volga), Samara rivers, with ...

with two rounded nutlets, each with a wing 1.5–2 cm long; the two wings spreading almost horizontally from each other.Ishikawa prefecture forestry research institute
Kominekaede
(in Japanese

Kota's Nature Photo Gallery

(in Japanese

It is most closely related to '' Acer tschonoskii'', which replaces it further north and at higher altitudes in Japan; they have very similar leaf form. ''Acer micranthum'' is cultivated as an

ornamental tree Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

in European and North American gardens, and has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...

’s

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

. Though hardy down to , it requires a sheltered position in neutral or

acid soil Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the neg ...

with sun or partial shade. Image:Acer_micranthum.jpg, Tree in cultivation, Denmark Acer micranthum foliage.JPG, Leaves, Rogów Arboretum, Poland Image:Acer micranthum SZ141.png, Illustration by Siebold & Zuccarini

References

{{Taxonbar, from=Q1631932 micranthum Endemic flora of Japan Trees of Japan Plants described in 1845 Dioecious plants