Acer rufinerve is a maple

Maple

Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...

 in the snakebark maple

Snakebark maple

Snakebark maples are maples belong to the taxonomic section Acer sect. Macrantha. The section includes 18–21 species, and is restricted to eastern Asia with the exception of one species in eastern North America....

 group, related to Acer capillipes

Acer capillipes

Acer capillipes , is a maple in the same taxonomic section as other snakebark maples such as A. pensylvanicum, A. davidii and A. rufinerve...

(Kyushu Maple). It is native to mountains forests of Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, on Honshū

Honshu

is the largest island of Japan. The nation's main island, it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Strait...

, Kyūshū

Kyushu

is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include , , and . The historical regional name is referred to Kyushu and its surrounding islands....

 and Shikoku

Shikoku

is the smallest and least populous of the four main islands of Japan, located south of Honshū and east of the island of Kyūshū. Its ancient names include Iyo-no-futana-shima , Iyo-shima , and Futana-shima...

.
It is a small deciduous

Deciduous

Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 growing to a height of 8–15 m, with a trunk up to 40 cm diameter. The bark

Bark

Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...

 on young trees is smooth, olive-green with regular narrow vertical pale green to greyish stripes and small greyish lenticel

Lenticel

A lenticel is an airy aggregation of cells within the structural surfaces of the stems, roots, and other parts of vascular plants. It functions as a pore, providing a medium for the direct exchange of gasses between the internal tissues and atmosphere, thereby bypassing the periderm, which would...

s; on old trees, it becomes rough and grey. The leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are three-lobed (occasionally five-lobed with two additional small basal lobes), double serrated, 8-16 cm long and 6-16 cm broad, matt to sub-shiny dark green above, paler below with small tufts of rusty hair on the veins when young, becoming glabrous when mature; the petiole is greenish (rarely pinkish), 3–5 cm long. The leaves turn to bright orange or red in the autumn. The flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s are produced in raceme

Raceme

A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...

s 10 cm long, each flower 8–10 mm diameter, with five yellow to greenish-yellow sepals and petals; it is dioecious

Plant sexuality

Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....

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

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 is a paired samara

Samara (fruit)

A samara is a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. A samara is a simple dry fruit and indehiscent . It is a winged achene...

 2–3 cm long with rounded nutlets. The scientific and English names derive from the reddish down on the veins, the Japanese name from the bark pattern.

It can be distinguished from the related Acer capillipes

Acer capillipes

Acer capillipes , is a maple in the same taxonomic section as other snakebark maples such as A. pensylvanicum, A. davidii and A. rufinerve...

(Japanese, ホソエカエデ hosoekaede), with which it often occurs, by the green petioles, the rufous hairs on the underside of the leaves (contrasting with the hairless or only thinly hairy A. capillipes leaves), and in flowering earlier in spring at the same time as the leaves appear.

Cultivation

This is one of the most commonly planted snakebark maples, and is a hardy, fast grower. It does not display much variation as a species but a notable cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

 is 'Erythrocladum' with yellow-green in both its leaves and the stripes of its bark. Variegated

Variegation

Variegation is the appearance of differently coloured zones in the leaves, and sometimes the stems, of plants. This may be due to a number of causes...

cultivars include 'Albolimbatum' and 'Hatsuyaki'.