|Also called: butterfly nut a threaded nut tightened by hand by means of two flat lugs or wings projecting from the central body|
(genus Pterocarya), any of about six species of Asian trees of the walnut family (Juglandaceae). They often are 30 m (about 100 feet) tall and bear winged, edible, one-seeded nuts. One species, P. stenoptera, is planted as an ornamental. The wood of some species is used in cabinetmaking.
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