Pterocarya

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids I
Ordo: Fagales

Familia: Juglandaceae
Subfamilia: Juglandoideae
Genus: Pterocarya
Species: P. fraxinifolia – P. hupehensis – P. macroptera – P. nanjiangensis – P. rhoifolia – P. stenoptera – P. tonkinensis
Paleospecies: †P. pugetensis
Name

Pterocarya Kunth, Ann. Sci. Nat. (Paris) 2: 345 (1824).

Type species: Pterocarya pterocarpa (Michx.) Kunth ex Iljinsk., Trudy Bot. Inst. Akad. Nauk S.S.S.R., Ser. 1, Fl. Sist. Vyssh. Rast. 47. (1953) (basionym: Juglans pterocarpa Michx., Fl. Bor.-Amer. 2: 192 (1803)) = Pterocarya fraxinifolia (Lam.) Spach

Distribution
Native distribution areas:

Continental: Europe (introduced)
Regional: Northern Europe
Finland (rarely short-lived alien), Sweden.
Regional: Middle Europe
Belgium, Hungary.
Regional: Southwestern Europe
France.
Regional: Southeastern Europe
Italy.
Continental: Asia-Temperate
Regional: Middle Asia
Tadzhikistan (introduced).
Regional: Caucasus
North Caucasus, Transcaucasus.
Regional: Western Asia
Iran, Turkey.
Regional: China
China South-Central, Hainan, Manchuria, China North-Central, China Southeast, Tibet.
Regional: Eastern Asia
Japan, Korea, Taiwan.
Continental: Asia-Tropical
Regional: Indo-China
Laos, Vietnam.

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Kunth, K.S. 1824. Annales des Sciences Naturelles (Paris) 2: 345. BHL

Additional references

Wolfe, J.A. 1968. Paleogene biostratigraphy of nonmarine rocks in King County, Washington. U. S. Geological Survey Professional Paper: 571.

Links

Govaerts, R. et al. 2022. Pterocarya in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2022 Mar 03. Reference page.
Hassler, M. 2022. Pterocarya. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2022. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2022 Mar 03. Reference page.
International Plant Names Index. 2015. Pterocarya. Published online. Accessed: Jan. 26 2015.
Tropicos.org 2015. Pterocarya. Missouri Botanical Garden. Published online. Accessed: 26 Jan. 2015.

Vernacular names
dansk: Vingevalnød
English: Wingnut
suomi: Siipipähkinät
français: Ptérocaryer
日本語: サワグルミ

Pterocarya, often called wingnuts in English, are trees in the walnut family Juglandaceae. They are native to Asia. The botanic name is from Ancient Greek πτερον (pteron) "wing" + κάρυον (karyon) "nut".

Description

Pterocarya are deciduous trees, 10–40 m tall, with pinnate leaves 20–45 cm long, with 11–25 leaflets; the shoots have chambered pith, a character shared with the walnuts (Juglans) but not the hickories (Carya) in the same family.

The flowers are monoecious, in catkins. The seed catkins when mature (about six months after pollination) are pendulous, 15–45 cm long, with 20–80 seeds strung along them.

The seeds are a small nut 5–10 mm across, with two wings, one each side. In some of the species, the wings are short (5–10 mm) and broad (5–10 mm), in others longer (10–25 mm) and narrower (2–5 mm).
Species

There are six species.

Image	Scientific name	Common Name	Distribution
	Pterocarya fraxinifolia	Caucasian wingnut	Caucasus and Elburz mountains in southwest Asia.
	Pterocarya hupehensis	Hubei wingnut	Central China.
	Pterocarya macroptera	Large-winged wingnut	West and southwest China.
	Pterocarya rhoifolia	Japanese wingnut	Japan, eastern China (Shandong).
	Pterocarya stenoptera	Chinese wingnut	China, widespread.
	Pterocarya tonkinensis	Tonkin wingnut	Southernmost China (Yunnan), Indo-China.

Another species from China, the wheel wingnut with similar foliage but an unusual circular wing right round the nut (instead of two wings at the sides), previously listed as Pterocarya paliurus, has now been transferred to a new genus, as Cyclocarya paliurus.
Hybrids

Pterocarya × rehderiana - (P. fraxinifolia × P. stenoptera).

Uses
Wingnuts are very attractive, large and fast-growing trees, occasionally planted in parks and large gardens. The most common in general cultivation outside Asia is P. fraxinifolia, but the most attractive is probably P. rhoifolia. The hybrid P. × rehderiana, a cross between P. fraxinifolia and P. stenoptera, is even faster-growing and has occasionally been planted for timber production. The wood is of good quality, similar to walnut, though not quite so dense and strong.