Hypericum scouleri
Scouler's st john's wort
(c) Steve Matson, some rights reserved (CC BY), uploaded by Steve Matson · licence
Family: Hypericaceae · Type: Herb · Native
Hypericum scouleri (Scouler's st john's wort) is a native California herb in the Hypericaceae family, recognized by flat clasping leaves and fewer flowers than similar species.
Scouler's st john's wort is a California native perennial found in northwestern California, high Cascade Range, Sierra Nevada, San Francisco Bay Area, southern Coast Ranges, Transverse Ranges, Peninsular Ranges, and Modoc Plateau in wet meadows, streambanks, and mesic areas in chaparral and conifer forest at elevations below 2,940 meters. Flowering from June to September, this plant produces pale to bright yellow flowers with black-dotted petals 7 to 12 millimeters long, typically arranged in clusters of 3 to 25 per stem. Growing 20 to 70 centimeters tall with erect, slender stems emerging few from the base and featuring small sterile axillary branches, it has a taproot or rhizome system. Its leaves are 10 to 30 millimeters long, ovate to elliptic, with black-dotted margins and an almost clasping base, appearing flat with obscure undersurface dots. The fruit is a distinctive 6 to 7 millimeter, 3-lobed structure with tiny brown seeds less than 1 millimeter long.
Identification and appearance
Key characters: 6 sympatric species; diagnostic flat clasping leaves and fewer flowers than similar species
Habitat and range
Habitat: Wet meadows, streambanks, mesic areas in chaparral, conifer forest
Elevation: < 2940 m
California counties: Placer, Kern, San Bernardino, Mono, Tuolumne, Los Angeles, Modoc, Fresno, Plumas, Alpine, Amador, Contra Costa, Glenn, Humboldt, Lake, Lassen, Tulare, Madera, Riverside, Shasta, Sierra, Sonoma, Tehama, Trinity, Ventura, Butte, Calaveras, Del Norte, El Dorado, Siskiyou, Marin, Mariposa, Mendocino, Monterey, San Luis Obispo, Nevada, San Diego, Santa Clara, Inyo, Napa
Outside California: to western Canada, Montana, New Mexico
Bloom period
Hypericum scouleri blooms Jun-Sep.
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 scouleri native to California?
Yes. Hypericum scouleri is native to California (recorded as native).
When does Hypericum scouleri bloom?
Hypericum scouleri blooms Jun-Sep.
Where in California does Hypericum scouleri grow?
Hypericum scouleri occurs in Placer, Kern, San Bernardino, Mono, Tuolumne, Los Angeles, Modoc, Fresno and other counties, at elevations of < 2940 m.
What plant family does Hypericum scouleri belong to?
Hypericum scouleri is in the Hypericaceae family, genus Hypericum.
What habitat does Hypericum scouleri grow in?
Hypericum scouleri grows in Wet meadows, streambanks, mesic areas in chaparral, conifer 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.