Ilex aquifolium
English holly
Family: Aquifoliaceae · Type: Shrub / Tree · Not Native
Conservation status: Cal-IPC Yes
Ilex aquifolium (English holly) is a non-native California shrub / tree in the Aquifoliaceae family, recognized by Only holly family representative in California; European species naturalizing in coastal areas.
English holly is a naturalized shrub found in northern coastal California, Klamath Ranges, northern Coast Ranges, central Coast, San Francisco Bay Area, and other regions in cool, wooded areas at elevations below 200 meters. Flowering from May to June, this plant produces dull white flowers tiny and delicate. Growing as an erect shrub or small tree to 20 meters tall with many branches and minutely hairy branchlets, it develops a distinctive branching structure. Its leaves are stiff and leathery, 2.5 to 6 centimeters long, ovate or oblong-ovate with occasional spine-like teeth and an unusually variable shape that can change even within a single plant. The fruit is a smooth, round berry approximately 7 to 8 millimeters wide, adding visual interest to the plant's winter landscape.
Identification and appearance
Key characters: Only holly family representative in California; European species naturalizing in coastal areas
Habitat and range
Habitat: Cool, wooded areas
Elevation: < 200 m
California counties: Alameda, San Mateo, Monterey, Marin, San Luis Obispo, Butte, Contra Costa, Humboldt, Sonoma, Mendocino, El Dorado, Sacramento, San Francisco
Outside California: native to Europe, western Asia
Bloom period
Ilex aquifolium blooms May-Jun.
Conservation status
Cal-IPC Yes
How to tell it apart
vs Mahonia: Ilex has simple, alternate spine-toothed leaves and clustered red drupes; Mahonia (Oregon grape) has pinnately compound leaves with spiny leaflets, yellow flowers, and blue berries.; vs Quercus: Ilex has minutely spine-toothed leaves and clusters of red berry-like drupes; holly-leaf oaks (Quercus) bear acorns and inconspicuous catkins.; vs Prunus: Ilex fruit is a red multi-stoned drupe with dull white flowers in small axillary clusters; hollyleaf cherry (Prunus ilicifolia) has white flowers in racemes and a single-stoned purple-black cherry.; vs Osmanthus: Ilex leaves are alternate; Osmanthus (false holly) has opposite spiny leaves and fragrant white tubular flowers.; vs Heteromeles: Ilex has stiff spine-tipped leaves and small red drupes in axillary clusters; toyon (Heteromeles) has finely serrate (not spine-tipped) leaves and large flat-topped clusters of tiny red pomes.
Frequently asked questions
Is Ilex aquifolium native to California?
No. Ilex aquifolium is not native to California (recorded as not native).
When does Ilex aquifolium bloom?
Ilex aquifolium blooms May-Jun.
Where in California does Ilex aquifolium grow?
Ilex aquifolium occurs in Alameda, San Mateo, Monterey, Marin, San Luis Obispo, Butte, Contra Costa, Humboldt and other counties, at elevations of < 200 m.
What plant family does Ilex aquifolium belong to?
Ilex aquifolium is in the Aquifoliaceae family, genus Ilex.
Is Ilex aquifolium invasive in California?
Ilex aquifolium is listed by Cal-IPC with an invasiveness rating of Yes.
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.