# 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.

- **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.

## About

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.

## Sources

- Plate: https://gaia-dex.com/species/3ce978fd-2aee-425f-8bb4-771ddc309ada
- iNaturalist: https://www.inaturalist.org/taxa/54502
- Wikipedia: https://en.wikipedia.org/wiki/Juglans hindsii
- Conservation status: IUCN Red List category, as recorded by Gaia-Dex
- Photo: https://inaturalist-open-data.s3.amazonaws.com/photos/23895906/medium.jpeg (Anne Parsons, CC0, via iNaturalist)

Habitat, diet, size and similar notes are AI-written summaries; check them against the linked sources before relying on them.