Pterocarya stenoptera aka Chinese Wingnut

Pterocarya stenoptera, or Chinese wingnut, belongs to the walnut family. This deciduous tree is native to China and Taiwan. It grows on mountain slopes and along riverbanks. It also forms small stands in gaps within oak woods. Garden trees reach 50–70 feet [15–21.3 metres] in height. Their crowns can spread 40–70 feet [12–21.3 metres]. Oregon State gives a wider height range, reaching 90 feet [27 metres]. Growth is fast, with trees reaching 20 feet [6 metres] within five years.

The broad crown has spreading limbs and drooping branches. Some trees form more than one trunk. The open canopy casts patches of shade beneath its branches. Young twigs have a coat of tan hairs. New leaves also have a soft, downy cover. The pinnate leaves reach 1.25 feet [0.38 metres] long. Each carries 11–25 glossy, dark green leaflets with sharp teeth. The central leaf stalk has wings, which may have teeth. The end leaflet may be missing. Fall leaves may turn yellow-green, though some sources report no change.

Small, pale green flowers hang in catkins during May and June. The same tree bears both male and female flowers. Female catkins reach about 1.7 feet [0.51 metres] long. Male catkins reach about 0.6 feet [0.18 metres]. Winged nutlets form along the female catkins in early summer. These hanging fruit chains turn from green to brown in fall. The fruit gives the tree its common name. It draws more attention than the small flowers.

Grow this tree in full sun and well-drained soil. It prefers steady soil moisture but withstands some drought once established. It also grows in compacted clay. Most garden sources place it in USDA zones 6–8. Oregon State notes possible hardiness in zone 5. Its size suits parks and large sites needing shade. It needs ample room for both its crown and roots.

Surface roots can lift paving and make lawns uneven. The tree also sends up many suckers. Fallen leaves, fruits, and twigs add to cleanup work. Sources report no major pest or disease problems. Plants For A Future lists no known food uses or hazards. That does not establish that its parts are safe to eat. It records medicinal uses for leaves and stem bark. It also notes that the leaves have insecticidal properties.