Romneya coulteri
Coulter's matilija poppy
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Family: Papaveraceae · Type: Shrub · Native
Conservation status: CNPS 4.2
Romneya coulteri (Coulter's matilija poppy) is a native California shrub in the Papaveraceae family, recognized by (R. trichocalyx). Key difference is fruit size and seed texture/color.
Coulter's matilija poppy is a California native shrub found in southern California coastal regions, western Transverse Ranges, and Peninsular Ranges in dry washes and canyons at elevations below 1,200 meters. Flowering from March to July, this plant produces large, spectacular white flowers with bright yellow centers up to 20 centimeters in diameter. Growing as a robust, spreading shrub 1 to 2 meters tall with multiple woody stems, it creates dramatic visual displays in its native habitats. Its leaves are deeply lobed, grayish-green, and somewhat wrinkled, with a rough texture that helps distinguish this iconic California native. The fruit develops as a capsule approximately 3 to 4 centimeters long, containing dark brown seeds with a distinctive papillate surface.
Identification and appearance
Key characters: 1 sympatric species (R. trichocalyx). Key difference is fruit size and seed texture/color.
Habitat and range
Habitat: dry washes, canyons
Elevation: < 1200 m
California counties: Ventura, Orange, Los Angeles, San Diego, Riverside, San Bernardino, Santa Barbara, Butte, Alameda, Mariposa, Contra Costa, Santa Clara, El Dorado, Yolo
Bloom period
Romneya coulteri blooms Mar-Jul.
Conservation status
CNPS 4.2
How to tell it apart
vs Argemone: Shrub with deeply lobed leaves, not prickly-spiny herbaceous plant.; vs Rosa: Six white petals (not five), leaves deeply divided into narrow segments.; vs Cistus: Six white petals around golden center, not five petals with simple leaves.; vs Artemisia: Spectacular large white flowers 4+ inches across, not tiny in dense clusters.; vs Papaver: Large woody shrub with 6 petals, not herbaceous annual with 4 petals.
Frequently asked questions
Is Romneya coulteri native to California?
Yes. Romneya coulteri is native to California (recorded as native).
When does Romneya coulteri bloom?
Romneya coulteri blooms Mar-Jul.
Where in California does Romneya coulteri grow?
Romneya coulteri occurs in Ventura, Orange, Los Angeles, San Diego, Riverside, San Bernardino, Santa Barbara, Butte and other counties, at elevations of < 1200 m.
What plant family does Romneya coulteri belong to?
Romneya coulteri is in the Papaveraceae family, genus Romneya.
Is Romneya coulteri rare or endangered?
Romneya coulteri carries California Rare Plant Rank 4.2, state rank S4.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.