Juglans californica Juglans californica 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 walnut family, Juglandaceae, endemic to California. "Juglans californica" is generally found in the southern California Coast Ranges, Transverse Ranges, 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.
Green rosella eucalypts—forming the bulk of its diet; other items eaten include the seed of the soft tree fern ("Dicksonia antarctica"), cranberry heath ("Astroloma humifusum"), myrtle beech ("Lophozonia cunninghamii"), Australian blackwood ("Acacia melanoxylon"), silver wattle ("Acacia dealbata") and buttercups ("Ranunculus"), berries, nuts and fruit, as well as flowers and new buds of southern sassafras ("Atherosperma moschatum"), mānuka ("Leptospermum scoparium"), shining tea-tree ("Leptospermum nitidum"), swamp honey-myrtle ("Melaleuca squamea"), Tasmanian bluegum ("Eucalyptus globulus"), Smithton peppermint ("Eucalyptus nitida"), messmate stringybark ("Eucalyptus obliqua"), snow gum ("Eucalyptus pauciflora"), manna gum ("Eucalyptus viminalis"), small-fruit hakea ("Hakea microcarpa") and native plum ("Cenarrhenes nitida"). The green rosella has at times