It is a gray tree of the walnut family native exclusively to North
America. Hickory is a large, strong tree, 18 to 24 m (60 to 80 ft.)
high, with close, shaggy bark, the only part used. It has large
pinnately divided leaves; pistillate and staminate flowers; and
dropping aments. The fruit is a thick-shelled nut in a tough, green
husk. Various species are known: Carya ovata, shagbark hickory,
yielding sweeter and better nuts; C. laciniosa, kingnut or shellbark;
C. tomentosa, mockemut, having tough wood; and C. glabra,
pignut, having bitter, astringent nuts.
