walnutArticle Free Pass walnut, any of about 20 species of
deciduous trees constituting the genus Juglans of the family
Juglandaceae, native to North and South America, southern
Europe, Asia, and the West Indies. The trees have long leaves
with 5 to 23 short-stalked leaflets; male and female
reproductive organs are borne in different, petalless flower
clusters on the same tree; the twigs contain a many-chambered
pith; and the fruit is a woody nut enclosed in a thick husk.
Black walnut (J. nigra) of eastern North America and English, or
Persian, walnut (J. regia), native to Iran, are valuable timber
trees that produce edible nuts. The butternut (J. cinerea) of
eastern North America also produces an edible nut. See also
butternut. A black walnut tree usually is between 20 and 30 m
(about 65 and 100 feet) tall and has a trunk about 60 to 90 cm
(2 to 3 feet) in diameter, with a deeply furrowed, dark brown or
grayish black bark. The leaves, about 30 to 60 cm long, consist
of 15 to 23 leaflets borne on very short s