Juglans regia
Persian or english walnut, Persian Walnut
(c) Ed Alverson, some rights reserved (CC BY), uploaded by Ed Alverson · licence
Family: Juglandaceae · Type: Tree · Not Native
Juglans regia (Persian or english walnut) is a non-native California tree in the Juglandaceae family, recognized by (J. californica, J. hindsii). Key features: fewer leaflets, entire margins, larger leaflet size.
Persian walnut is a naturalized shrub found in northern North Coast Ranges, Great Valley, Central Western, and Southwestern California near cultivated trees at elevations below 200 meters. Flowering in April, this plant produces small, unremarkable flowers. Growing to a substantial trunk height of 5 to 30 meters with spreading branches, it develops a wide canopy. Its leaves are compound with 5 to 11 elliptic to oblong-ovate leaflets, each 10 to 22 centimeters long, with distinctive tufts of hair in the leaf vein axils. The fruit is a large walnut approximately 3.5 to 5 centimeters in diameter with a thin, wrinkled shell.
Identification and appearance
Key characters: 2 sympatric species (J. californica, J. hindsii). Key features: fewer leaflets, entire margins, larger leaflet size
Habitat and range
Habitat: Seedlings occasionally near cultivated trees
Elevation: < 200 m
Outside California: native to southwestern Asia
Bloom period
Juglans regia blooms Apr.
How to tell it apart
vs Ailanthus: Juglans leaflets lack the gland-teeth at the base that tree-of-heaven shows.; vs Carya: Juglans twigs have chambered centers; hickory twigs are solid throughout.; vs Pistacia: Juglans has chambered twig pith; pistachio has solid pith and resinous smell.; vs Aesculus: Juglans has alternate pinnate leaves; buckeye has opposite palmate leaves with 5-7 leaflets.; vs Fraxinus: Juglans produces nuts in sticky husks; ash produces flat papery winged seeds.
Frequently asked questions
Is Juglans regia native to California?
No. Juglans regia is not native to California (recorded as not native).
When does Juglans regia bloom?
Juglans regia blooms Apr.
What plant family does Juglans regia belong to?
Juglans regia is in the Juglandaceae family, genus Juglans.
What habitat does Juglans regia grow in?
Juglans regia grows in Seedlings occasionally near cultivated trees.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.