Northern California black walnut

In brief

Juglans hindsii, Juglandaceae.

- Deciduous tree, to 25 m
- Native to California, wild in only a few places
- Catkins in April and May
- Fruit a round nut in a thick green husk

Where it grows

Streambanks and valley bottoms. The genuinely wild stands are down to a handful of sites in the Coast Ranges and along the Sacramento; everything else in California is descended from planted trees.

When it blooms

April and May, in hanging green catkins.

Seed and fruit

A round nut in a thick green husk that stains anything that handles it. The shell is very hard and the kernel is small.

Here

Photographed with green fruit on August 30, 2026.

This species was the standard rootstock for English walnut orchards across California for a century, so a black walnut standing on old orchard country is usually a rootstock that outlived the graft above it. Native to the state, and not native to this hillside.

The species is not settled. Eastern black walnut and the hybrid between the two are both planted in California, and all three carry the same pinnate leaf and round husked nut. Counting leaflets is what would close it.