Walnuts (genus Juglans) are plants in the family Juglandaceae. They are deciduous trees, 30–130 ft tall with pinnate leaves and with 5–25 leaflets. The shoots have chambered pith, a character that can quickly confirm the tree's identification. There are 21 species in the genus range across the north temperate Old World from southeast Europe east to Japan, and more widely in the New World from southeast Canada west to California and south to Argentina. The Latin name, Juglans, derives from Jovis glans, "Jupiter's acorn": figuratively, a nut fit for a god.
The Common North American Walnut Species
Bark is furrowed and dark in black walnut (lighter in butternut); leaf scars like upside down shamrock with 5 or 7 bundle scars; walnuts and husks often under tree; has chambered pith; has globose nut (butternut more egg-shaped and smaller).
Leaves: mostly alternate, odd
Fruit: hard-shelled nut.