Juglans californica
Encyclopedia
Juglans californica, the California black walnut, also called the California walnut, or the Southern California black walnut, is a large shrub or small tree (up to 30 feet tall) of the Juglandaceae
(walnut) family endemic to California
.
, and Peninsular Ranges
, and the Central Valley. It grows as part of mixed woodlands, and also on slopes and in valleys wherever conditions are favorable. It is threatened by development and overgrazing. Some native stands remain in urban Los Angeles
in the Santa Monica Mountains
and Hollywood Hills
. J. californica grows in riparian woodlands, either in single species stands or mixed with California's oaks
(Quercus spp.) and cottonwoods (Populus fremontii
).
ly compound leaves with 11-19 lanceolate leaflets with toothed margins and no hair in the vein angles. It has a small hard nut in a shallowly grooved, thick shell that is difficult to remove.
and Ventura County
once ate the nuts; however, they are not grown commercially for this purpose.
, xeriscape
, and wildlife habitat
gardens and natural landscaping
in California, and in Hawaii.
) combine this species with J. hindsii. On the other hand, a 2007 molecular analysis of the genus suggests J. californica is sister to the remaining black walnuts (Rhysocaryon). This article follows the conventions of The Jepson Manual. .
Juglandaceae
The Juglandaceae, also known as the Walnut Family, is a family of trees, or sometimes shrubs, in the order Fagales. Various members of this family are native to the Americas, Eurasia, and Southeast Asia....
(walnut) family endemic to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
.
Distribution
J. californica is generally found in the southern California Coast Ranges, Transverse RangesTransverse Ranges
The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region that runs along the Pacific coast from Alaska to Mexico in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie between...
, and Peninsular Ranges
Peninsular Ranges
The Peninsular Ranges are a group of mountain ranges, in the Pacific Coast Ranges, which stretch from southern California in the United States to the southern tip of Mexico's Baja California peninsula; they are part of the North American Coast Ranges that run along the Pacific coast from Alaska...
, and the Central Valley. It grows as part of mixed woodlands, and also on slopes and in valleys wherever conditions are favorable. It is threatened by development and overgrazing. Some native stands remain in urban Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
in the Santa Monica Mountains
Santa Monica Mountains
The Santa Monica Mountains are a Transverse Range in Southern California, along the coast of the Pacific Ocean in the United States.-Geography:...
and Hollywood Hills
Hollywood Hills
The Hollywood Hills is an affluent and exclusive neighborhood of Los Angeles, California, in the southeastern Santa Monica Mountains. It is bound by Laurel Canyon Boulevard to the west, Vermont Avenue to the east, Mulholland Drive to the north, and Sunset Boulevard to the south.-Hollywood Hills...
. J. californica grows in riparian woodlands, either in single species stands or mixed with California's oaks
California oak woodland
California oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico...
(Quercus spp.) and cottonwoods (Populus fremontii
Populus fremontii
Populus fremontii, the Fremont cottonwood or Alamo cottonwood, is a cottonwood poplar native to western North America, in California and east to Nevada, Utah, Arizona, and New Mexico, and south into Sonora in northwestern Mexico...
).
Description
Juglans californica can be either a large shrub with 1-5 trunks, or a small, single-trunked tree. The main trunk can fork close to the ground, making it look like two trees that have grown together, then diverged. It has thick bark, deeply channeled or furrowed at maturity. It has large, pinnatePinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
ly compound leaves with 11-19 lanceolate leaflets with toothed margins and no hair in the vein angles. It has a small hard nut in a shallowly grooved, thick shell that is difficult to remove.
Food
The Chumash Indians of the Channel Islands of CaliforniaChannel Islands of California
The Channel Islands of California are a chain of eight islands located in the Pacific Ocean off the coast of Southern California along the Santa Barbara Channel in the United States of America...
and Ventura County
Ventura County, California
Ventura County is a county in the southern part of the U.S. state of California. It is located on California's Pacific coast. It is often referred to as the Gold Coast, and has a reputation of being one of the safest populated places and one of the most affluent places in the country...
once ate the nuts; however, they are not grown commercially for this purpose.
Cultivation
J. californica is cultivated as an ornamental tree where it is planted in California native plantCalifornia native plants
California native plants are plants that existed in California prior to the arrival of European explorers and colonists in the late 18th century...
, xeriscape
Xeriscaping
Xeriscaping and xerogardening refers to landscaping and gardening in ways that reduce or eliminate the need for supplemental water from irrigation...
, and wildlife habitat
Backyard Wildlife Habitat
Backyard Wildlife Habitat is a program of the National Wildlife Federation that encourages homeowners in the United States to manage their gardens and yards as a wildlife garden, with the goal of maintaining healthy and diverse animal habitats and ecosystems...
gardens and natural landscaping
Natural landscaping
.Natural landscaping, also called native gardening, is the use of native plants, including trees, shrubs, groundcover, and grasses which are indigenous to the geographic area of the garden.-Maintenance:...
in California, and in Hawaii.
Taxonomy
Some authorities (e.g. the California Native Plant SocietyCalifornia Native Plant Society
The California Native Plant Society is a California not-for-profit organization that seeks to increase understanding of California's native flora and to preserve that flora. Its "paramount purpose is to preserve wild plants".-History:...
) combine this species with J. hindsii. On the other hand, a 2007 molecular analysis of the genus suggests J. californica is sister to the remaining black walnuts (Rhysocaryon). This article follows the conventions of The Jepson Manual. .