''Juglans mandshurica'' (), also known as Manchurian walnut, or Tigernut, is a

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

tree of the genus ''

Juglans Walnut trees are any species of tree in the plant genus ''Juglans'', the type genus of the family Juglandaceae, the seeds of which are referred to as walnuts. All species are deciduous trees, tall, with pinnate leaves , with 5–25 leaflets ...

'' (section ''Cardiocaryon''), native to the Eastern Asiatic Region ( China,

Russian Far East The Russian Far East (russian: Дальний Восток России, r=Dal'niy Vostok Rossii, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in Northeast Asia. It is the easternmost part of Russia and the Asian continent; and is admin ...

North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and shares borders with China and Russia to the north, at the Yalu (Amnok) and T ...

and

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korean Peninsula and sharing a land border with North Korea. Its western border is formed by the Yellow Sea, while its eas ...

). It grows to about 25 m. This species was first described by the

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

n botanist Carl Johann Maximowicz, in ''Bulletin de la Classe Physico-Mathématique de l'Académie Impériale des Sciences de Saint-Pétersbourg'', which was published in 1856. The leaves are alternate, 40–90 cm long, odd-pinnate, with 7–19 leaflets, 6–17 cm long and 2–7.5 cm broad (margin serrate or serrulate, apex acuminate). The male

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s are in drooping catkins 9–40 cm long, the wind-pollinated female flowers (April–May) are terminal, in spikes of 4 to 10, ripening in August–October into nuts, 3-7.5 × 3–5 cm, with densely glandular pubescent green husk and very thick shell. The tree is exceptionally hardy (down to at least -45 °C), has a relatively short vegetation period compared to other walnuts, grows rapidly and is cultivated as an ornamental in colder temperate regions all over the Northern Hemisphere. (For example, it has been found to grow satisfactorily in Edmonton, Alberta, Canada.) The kernels of the nuts are edible, but small and difficult to extract. The timber is in use, but less valuable than that of English walnut or black walnut. The Manchurian walnut contains and exudes much lesser quantities of allelopathic compounds (such as

juglone Juglone, also called 5-hydroxy-1,4-naphthalenedione (IUPAC) is an organic compound with the molecular formula C10H6O3. In the food industry, juglone is also known as C.I. Natural Brown 7 and C.I. 75500. It is insoluble in benzene but soluble i ...

) than other popular ''Juglans'' speciesПомогайбин А.В., Кавеленова Л.М., Силаева О.Н. (2002)
Некоторые особенности химического состава и биологической активности листового отпада видов рода орех (''Juglans'' L.) при интродукции в Среднем Поволжье
. ''Химия растительного сырья'' 4, 43-47. and usually causes few significant allelopathic effects in cultivation. ''Juglans cathayensis'', characterized by tomentose leaflets, producing more flowers per spike and growing south of the

Yellow River The Yellow River or Huang He (Chinese: , Mandarin: ''Huáng hé'' ) is the second-longest river in China, after the Yangtze River, and the sixth-longest river system in the world at the estimated length of . Originating in the Bayan Ha ...

, was sometimes recognized as a species separate from ''J. mandshurica''. The Japanese walnut (オニグルミ) is listed by some authorities as ''Juglans mandshurica'' var. ''sachalinensis'' (syn. '' Juglans ailantifolia'').

References

External links

Juglans mandshurica
@ Flora of China {{Taxonbar, from=Q311361 mandshurica Flora of China Trees of Korea Flora of Russia Trees of Russia Trees of continental subarctic climate Fruit trees Taxa named by Karl Maximovich