Native Plant Gardening 101: Developing an Understory 

The San Fernando Valley species of native walnut is Juglans californica and is used for a rootstock for commercial English Walnuts that you buy in the market. I recall hearing that the San Fernando Valley has its own special subspecies. As per wikipedia, the Jepson Manual considers the walnut native to Southern California, Juglans californica that grows in the transverse range, the Santa Monica Mountains and Los Angeles area valleys) to be separate species from the walnut that grows in North-Central and Northern California, Juglans hindsii. The California Native Plant Society considers them to be the same species, genetics suggests they are closely related species. I am not a formally trained botanist, but I'm familiar with both, and find them to be easily distinguishable at first glance and that their nuts alone also have easily identifiable differences.

"promo sm"