The Southern California black walnut is a large deciduous shrub or tree that commonly grows with many trunks. Over time it can reach heights of 20-35 ft. Leaves are deep green and pinnately divided into 11-19 leaflets. Flowering occurs in early spring; small round walnuts mature by late fall. The nuts are of little commercial value, but are important to wildlife.
The Southern California black has suffered extensive loss through urbanization and is now a protected species in several counties and cities. It is mostly planted in revegetation projects on slopes and for wildlife habitat, and can be found in regional parks and protected natural areas.