''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, e.g., including only woody plants with secondary growth, only ...

s in the walnut family

Juglandaceae The Juglandaceae are a plant family known as the walnut family. They are trees, or sometimes shrubs, in the order Fagales. Members of this family are native to the Americas, Eurasia, and Southeast Asia. The nine or ten genera in the family have ...

. They are native to

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. The botanic name is from

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

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

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 Leaf, 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 ...

leaves 20–45 cm long, with 11–25 leaflets; the shoots have chambered

pith Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which in some cases can store starch. In eudicotyledons, pith is located in the center of the stem. In monocotyledons, it ex ...

, a character shared with the walnuts (''

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

'') but not the hickories ('' Carya'') in the same family. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are organized in male and female

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''). It contains many, usually unisexual flowers, arra ...

s in the same tree. Therefore the species is monoecius. 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 In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

s 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. 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

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 bot ...

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 uniform and useful sizes (dimensional lumber), including beams and planks or boards. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, window frames). ...

production. The

wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...

is of good quality, similar to

walnut A walnut is the edible seed of any tree of the genus '' Juglans'' (family Juglandaceae), particularly the Persian or English walnut, '' Juglans regia''. They are accessory fruit because the outer covering of the fruit is technically an i ...

, though not quite so dense and strong.

External links

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