northern California black walnut

Juglans hindsii

Almost all commercial English walnuts are grafted onto Northern California black walnut rootstock because of its superior resistance to soil-borne pests.

Scientific name
Juglans hindsii
Taxonomy
Plantae › Tracheophyta › Magnoliopsida › Fagales › Juglandaceae › Juglans
IUCN Red List status
Vulnerable
Population trend
decreasing
Biome
forest
Habitat
Riparian woodlands, floodplains, and valley bottoms near permanent water sources.
Diet
Photosynthetic (Sunlight, Water, Carbon Dioxide, and Soil Minerals).
Range
Northern California, Sacramento Valley, Napa County, Contra Costa County
Size
15 to 25 meters tall with a trunk diameter up to 1.5 meters.
Lifespan
100-150 years
Active
diurnal
Threats
Habitat loss due to agriculture and urbanization, and genetic swamping through hybridization with commercial English walnuts.
Safe to approach?
Harmless to humans. The nuts are edible but have very hard shells; use caution when cracking. The tree produces juglone, a natural herbicide in its roots and husks that can cause mild skin irritation in sensitive individuals and is toxic to many other plant species. Safe to approach and touch.

Juglans hindsii , commonly called the Northern California walnut and Hinds' black walnut , is a species of walnut tree endemic to Northern California. It is commonly called claro walnut by the lumber industry and woodworkers, and is the subject of some confusion over its being the root stock for English walnut orchard stock.

Photo: Anne Parsons, CC0, via iNaturalist

Plain-text version: /species/3ce978fd-2aee-425f-8bb4-771ddc309ada.md