Northern California Walnut
Juglans hindsii
The Northern California Walnut is a large tree with a single straight trunk stretching up to 60 feet tall. Near its base, the trunk is stout and knotted, commonly reaching 5-6 ft in diameter, but it narrows out further up. The shallowly grooved, dark brown trunk soars up to 40 feet before branches emerge to form a wide, leafy crown. The light green leaf is made up of 13-21 thin, serrated leaflets, each 2.5 inches long, which attach to a foot long stem in a pinnately compound pattern (ie. in opposite pairs except for a leaflet at the point). The soft, white nut is contained in a thick, brown shell — a normal walnut for all purposes. The inconspicuous green flowers bloom on dangling catkins.
Basic Information
Member of the Juglandaceae, or walnut, family
Winter deciduous
Sometimes considered a subspecies of the Southern California Black Walnut
Habitat
Native to California
Endemic to a roughly circular area centered near Fresno and reaching the San Francisco Bay area
Typically found in riparian woodlands and mixed oak woodlands
Ecological Role
Nut is important food source for wildlife
Host plant for the larva of the Pale Swallowtail, Two-tailed Swallowtail, and Western Tiger Swallowtail butterflies
Reproduction
Blooms from April-June
Monoecious — individual flowers are either male or female, but both found on same plan
Alternative Names
Northern California Walnut, Hind’s Black Walnut
Commonly called claro walnut by the lumber industry
Historical Uses
The Kashaya Pomo created a black dye out of the root for basket-making
Many tribes ate and stored the nut meat for food
Additional Information
Formerly assessed as Seriously Endangered on the California Native Plant Society Rare Plant Inventory; however, its status was revised to common in 2019
Still threatened by hybridization with orchard trees, urbanization, and habitat loss
