Hypericum calycinum
Aaron's beard
(c) H. Zell, some rights reserved (CC BY-SA) · licence
Family: Hypericaceae · Type: Shrub · Not Native
Hypericum calycinum (Aaron's beard) is a non-native California shrub in the Hypericaceae family, recognized by large flowers with red anthers.
Aaron's beard is a naturalized shrub found in northern coastal California, central Sierra Nevada, central Coast Coast, and San Francisco Bay Areas in shaded wildland-urban interface zones at elevations below 1,040 meters. Flowering from June to November, this plant produces large bright yellow flowers 25 to 40 millimeters long with distinctive red-colored anthers. Growing as an evergreen shrub 20 to 60 centimeters tall with creeping stolons and erect, slightly branched stems, it spreads easily in transitional landscape environments. Its oblong to narrow-ovate leaves are 4.5 to 10 centimeters long, decorated with fine gland-dotted or gland-streaked surfaces. The mature fruit develops as an ovoid structure 10 to 20 millimeters long, containing small red-brown seeds with a finely netted surface.
Identification and appearance
Key characters: 6 sympatric species; diagnostic large flowers with red anthers
Habitat and range
Habitat: Shaded wildland-urban interface
Elevation: < 1040 m
California counties: Humboldt, Contra Costa, Madera, San Francisco, San Mateo, El Dorado, Del Norte, Marin, Santa Cruz, Butte, Tuolumne, San Luis Obispo, Alameda, Sonoma
Outside California: native to Turkey
Bloom period
Hypericum calycinum blooms Jun-Nov.
How to tell it apart
vs Euphorbia: Euphorbia has milky sap and tiny flowers in cups; Hypericum has clear sap and showy yellow flowers.; vs Lysimachia: Lysimachia has stamens separate, not bundled; Hypericum's stamens cluster into 3-5 distinct bunches.; vs Lonicera: Lonicera is a woody vine or shrub; Hypericum is herbaceous with opposite leaves.; vs Dendromecon: Dendromecon is a woody shrub with 4 petals; Hypericum is herbaceous with 5 petals.; vs Mentzelia: Mentzelia has rough, sandpapery leaves; Hypericum has smooth leaves with translucent dots.
Frequently asked questions
Is Hypericum calycinum native to California?
No. Hypericum calycinum is not native to California (recorded as not native).
When does Hypericum calycinum bloom?
Hypericum calycinum blooms Jun-Nov.
Where in California does Hypericum calycinum grow?
Hypericum calycinum occurs in Humboldt, Contra Costa, Madera, San Francisco, San Mateo, El Dorado, Del Norte, Marin and other counties, at elevations of < 1040 m.
What plant family does Hypericum calycinum belong to?
Hypericum calycinum is in the Hypericaceae family, genus Hypericum.
What habitat does Hypericum calycinum grow in?
Hypericum calycinum grows in Shaded wildland-urban interface.
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.