Notholithocarpus densiflorus var. densiflorus
Tanoak
Photo: parent species Notholithocarpus densiflorus · (c) Adam J. Searcy, some rights reserved (CC BY) · licence
Family: Fagaceae · Type: Shrub / Tree · Native
Notholithocarpus densiflorus var. densiflorus (Tanoak) is a native California shrub / tree in the Fagaceae family, recognized by 1 sympatric variety; differs by larger leaf size and lower elevation forest habitat.
Tanoak is a native shrub found in northwestern California, the Cascade Range, Sierra Nevada, central western California, and western Transverse Ranges in redwood and mixed-evergreen forests at elevations below 1,500 meters. Flowering from June to October, this plant produces flowers in dense clusters. Growing to a substantial shrub size with multiple stems, it forms dense thickets in forest understories. Its leathery leaves are large, measuring 4 to 14 centimeters long and 12 to 40 millimeters wide, with a thick, durable texture characteristic of woodland understory species. The shrub provides critical habitat and food resources for numerous forest ecosystem inhabitants.
Identification and appearance
Key characters: 1 sympatric variety; differs by larger leaf size and lower elevation forest habitat
Habitat and range
Habitat: Redwood, mixed-evergreen forest
Elevation: < 1500 m
California counties: Monterey, Humboldt, Santa Cruz, Santa Barbara, Sonoma, Mendocino, San Mateo, Siskiyou, Del Norte, San Luis Obispo, Trinity, Marin, Santa Clara, Butte, Mariposa, Sierra, El Dorado, Ventura, Napa
Outside California: southern Oregon
Bloom period
Notholithocarpus densiflorus var. densiflorus blooms Jun-Oct.
How to tell it apart
vs Quercus: Notholithocarpus has erect flower spikes; oak catkins hang downward.; vs Heteromeles: Notholithocarpus has acorns in cups; toyon has red berry clusters.; vs Frangula: Notholithocarpus has acorns; Frangula has smooth berry-like fruits.; vs Chrysolepis: Notholithocarpus has cup-scaled acorns; Chrysolepis nuts are in spiny burs.; vs Alnus: Notholithocarpus has acorns; alders have small woody cones.
Frequently asked questions
Is Notholithocarpus densiflorus var. densiflorus native to California?
Yes. Notholithocarpus densiflorus var. densiflorus is native to California (recorded as native).
When does Notholithocarpus densiflorus var. densiflorus bloom?
Notholithocarpus densiflorus var. densiflorus blooms Jun-Oct.
Where in California does Notholithocarpus densiflorus var. densiflorus grow?
Notholithocarpus densiflorus var. densiflorus occurs in Monterey, Humboldt, Santa Cruz, Santa Barbara, Sonoma, Mendocino, San Mateo, Siskiyou and other counties, at elevations of < 1500 m.
What plant family does Notholithocarpus densiflorus var. densiflorus belong to?
Notholithocarpus densiflorus var. densiflorus is in the Fagaceae family, genus Notholithocarpus.
What habitat does Notholithocarpus densiflorus var. densiflorus grow in?
Notholithocarpus densiflorus var. densiflorus grows in Redwood, mixed-evergreen forest.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · 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.