Juglans ailantifolia the Japanese Walnut, is a species of walnut

Walnut

Juglans is a plant genus of the family Juglandaceae, the seeds of which are known as walnuts. They are deciduous trees, 10–40 meters tall , with pinnate leaves 200–900 millimetres long , with 5–25 leaflets; the shoots have chambered pith, a character shared with the wingnuts , but not the hickories...

 native to 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...

 and Sakhalin

Sakhalin

Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...

. It is a 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 20 m tall, rarely 30 m, and 40-80 cm stem diameter, with light 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 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 pinnate, 50-90 cm long, with 11-17 leaflets, each leaflet 7-16 cm long and 3-5 cm broad. The whole leaf is downy-pubescent, and a somewhat brighter, yellower green than many other tree leaves. 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 inconspicuous yellow-green catkin

Catkin

A catkin or ament is a slim, cylindrical flower cluster, with inconspicuous or no petals, usually wind-pollinated but sometimes insect pollinated . They contain many, usually unisexual flowers, arranged closely along a central stem which is often drooping...

s produced in spring at the same time as the new leaves appear. 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 nut

Nut (fruit)

A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...

, produced in bunches of 4-10 together; the nut is spherical, 3-5 cm long and broad, surrounded by a green husk before maturity in mid autumn.

Uses

The edible nuts have an oily texture. The husks are also used to make a yellowish dye.

The very bold, decorative leaves and the attractive catkins produced in spring make it an excellent ornamental tree

Ornamental plant

Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...

 for planting in park

Park

A park is a protected area, in its natural or semi-natural state, or planted, and set aside for human recreation and enjoyment, or for the protection of wildlife or natural habitats. It may consist of rocks, soil, water, flora and fauna and grass areas. Many parks are legally protected by...

s and large garden

Garden

A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...

s.
Unlike the closely related and very similar North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

n Butternut

Butternut (tree)

Juglans cinerea, commonly known as Butternut or White Walnut, is a species of walnut native to the eastern United States and southeast Canada. Its range extends east to New Brunswick, and from southern Quebec west to Minnesota, south to northern Alabama and southwest to northern Arkansas...

, Japanese Walnut is resistant to the canker

Canker

Canker and anthracnose are general terms for a large number of different plant diseases, characterised by broadly similar symptoms including the appearance of small areas of dead tissue, which grow slowly, often over a period of years. Some are of only minor consequence, but others are ultimately...

 disease

Disease

A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 caused by the fungus

Fungus

A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...

 Sirococcus clavigignenti-juglandacearum. This has led to its being planted as a replacement for Butternuts in North America. The two species hybridise readily; the resulting hybrid Juglans x bixbyi is also resistant to canker and is likewise planted as a replacement for Butternuts. Japanese Walnut is distinguished from Butternut by its larger leaves and round (not oval) nuts.

The wood

Wood

Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 is light and takes polish well, but is of much lower quality than Persian Walnut

Persian Walnut

Juglans regia, the Persian walnut, English walnut, or especially in Great Britain, Common walnut, is an Old World walnut tree species native to the region stretching from the Balkans eastward to the Himalayas and southwest China...

 wood. It is often used to make furniture

Furniture

Furniture is the mass noun for the movable objects intended to support various human activities such as seating and sleeping in beds, to hold objects at a convenient height for work using horizontal surfaces above the ground, or to store things...

.

Cultivars

The Heartnut is a 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...

of Japanese Walnut distinguished by its fruit, which is heart-shaped in cross section, easier to crack, and able to yield an unbroken nut meat when cracked. The Heartnut is a sweet nut without a bitter aftertaste often intrinsic with Black and Persian Walnuts.

Diseases

The only significant disease Japanese Walnuts are susceptible to is the Walnut Bunch Disease.

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