California black walnut
Juglans californica
Family: Juglandaceae.
Type: Deciduous tree.
Branching: Alternate.
Leaves: Pinnately compound, with 7-15 leaflets per leaf. Leaflets are narrow and variably toothed.
Twig: The terminal bud on the black walnut is very long and brown, while lateral buds are small and round. The bark is dark and ridged.
Fruit & Flower: Fruit is a large round nut, the walnut.
Miscellaneous: Walnuts in California are often grafts of Persian (also known as English) walnut onto rootstock of black walnut; the Persian walnuts are preferred for eating, but are susceptible to a root rot that the black walnut is not. This can be seen in a very clear change in bark color and texture partway up the main stem.