Sorbus alnifolia Alder-leafed Whitebeam or Korean Whitebeam; ) is a species of whitebeam

Whitebeam

The whitebeams are members of the Rosaceae family, comprising subgenus Aria of genus Sorbus, and hybrids involving species of this subgenus and members of subgenera Sorbus, Torminaria and Chamaemespilus. They are deciduous trees with simple or lobed leaves, arranged alternately...

 native to eastern Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 in China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

, Korea

Korea

Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...

 and 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...

.

Description

It is a medium-sized 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 10–20 m tall with a trunk up to 30 cm diameter and grey 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...

; the crown is columnar or conic in young trees, becoming rounded with age, with branches angled upwards, and slender shoots. 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 green above, and thinly hairy with white hairs beneath, 5–10 cm long and 3–6 cm broad, simple, usually unlobed (but see varieties, below), broadest near the base, with serrated margins and an acute apex. The autumn colour is orange-pink to red. 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 10–18 mm diameter, with five white petals and 20 yellowish-white stamens; they are produced in corymbs 4–8 cm diameter in late spring. 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 globose pome

Pome

In botany, a pome is a type of fruit produced by flowering plants in the subfamily Maloideae of the family Rosaceae.A pome is an accessory fruit composed of one or more carpels surrounded by accessory tissue...

 8–15 mm diameter, bright red, with a dimple at the apex; they are mature in mid autumn.

There are three varieties

Variety (biology)

In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....

:

• Sorbus alnifolia var. alnifolia. Leaves unlobed. Throughout the range of the species.
• Sorbus alnifolia var. angulata S.B.Liang. Leaves weakly lobed; fruit oblong. Northeast China, Korea.
• Sorbus alnifolia var. lobulata Rehder. Leaves weakly lobed; fruit globose. Shandong Province.

It has sometimes been placed in a separate genus of its own as Micromeles alnifolia, differing from other whitebeams in the deciduous sepals on the fruit (persistent in other whitebeams), but genetic evidence places it close to Sorbus aria

Sorbus aria

Sorbus aria , the Whitebeam or Common Whitebeam is a deciduous tree, compact and domed, with few upswept branches; it generally favours dry limestone and chalk soils. The hermaphrodite cream-white flowers appear in May, are insect pollinated, and go on to produce scarlet berries, which are often...

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Cultivation and uses

It is occasionally grown as an ornamental tree in northern Europe, primarily for its autumn colour. The 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...

'Skyline' has been selected for its fastigiate growth.