''Pterocarya'', often called wingnuts in English, are

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s in the walnut family Juglandaceae. They are native to

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

. The botanic name is from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

(''pteron'') "wing" + (''karyon'') "

nut Nut often refers to: * Nut (fruit), fruit composed of a hard shell and a seed, or a collective noun for dry and edible fruits or seeds * Nut (hardware), fastener used with a bolt Nut or Nuts may also refer to: Arts, entertainment, and media Com ...

Description

''Pterocarya'' are

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, aft ...

s, 10–40 m tall, with

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

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

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

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is conne ...

, in

catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged cl ...

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

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s are a small

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. 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 ''Cyclocarya'' is a genus of flowering plants in the family Juglandaceae, comprising a single species ''Cyclocarya paliurus'' (qing qian liu or wheel wingnut), formerly treated in the genus ''Pterocarya'' as ''Pterocarya paliurus''. It is native ...

''.

Hybrids

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

Uses

Wingnuts are very attractive, large and fast-growing trees, occasionally planted in

park A park is an area of natural, semi-natural or planted space set aside for human enjoyment and recreation or for the protection of wildlife or natural habitats. Urban parks are urban green space, green spaces set aside for recreation inside t ...

s and large

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate both ...

s. 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 Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, wi ...

production. The

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...

is of good quality, similar to walnut, though not quite so dense and strong.

External links

Flora of China - ''Pterocarya''Flora of China - ''Cyclocarya''
{{Taxonbar, from=Q1420126