Crocanthemum greenei
Island rush-rose, Island Rush-Rose
(c) Trevor Van Loon, some rights reserved (CC BY) · licence
Family: Cistaceae · Type: Shrub · Native
Conservation status: CNPS 1B.2 · Threatened
Crocanthemum greenei (Island rush-rose) is a native California shrub in the Cistaceae family.
Island rush-rose is a rare (CNPS 1B.2) California native perennial found in the Channel Islands on dry, rocky slopes and ridges in chaparral at elevations below 500 meters. Flowering from April to May, this plant produces yellow flowers with delicate petals 5 to 8 millimeters long in small clusters. Growing with erect green stems 15 to 68 centimeters tall, it forms a compact clump with multiple branching stems. Its leaves are small, narrow, and mostly 7 to 25 millimeters long with margins that do not curl under, creating a delicate green texture. The flower is distinguished by its distinctive sepals, with outer sepals 2.5 to 4 millimeters long and inner sepals 4.5 to 8 millimeters long, giving the plant an intricate floral structure.
Identification and appearance
Key characters: Endemic to Channel Islands with 2 sympatric taxa; geography is primary differentiator
Habitat and range
Habitat: Dry, rocky slopes, ridges in chaparral
Elevation: < 500 m
California counties: Los Angeles, Santa Barbara
Bloom period
Crocanthemum greenei blooms Apr-May.
Conservation status
CNPS 1B.2 · Threatened
How to tell it apart
vs Helianthemum: Crocanthemum has alternate stem leaves; Helianthemum has opposite stem leaves.; vs Acmispon: Acmispon has compound leaves with 3-5 leaflets and pea-shaped flowers; Crocanthemum has simple leaves and flat 5-petaled flowers.; vs Dendromecon: Dendromecon is a large shrub with leathery gray-green leaves; Crocanthemum is a ground-hugging herb.; vs Oenothera: Oenothera flowers have 4 petals and an X-shaped stigma; Crocanthemum has 5 petals.; vs Eschscholzia: Eschscholzia has finely dissected ferny leaves; Crocanthemum has simple entire leaves.
Frequently asked questions
Is Crocanthemum greenei native to California?
Yes. Crocanthemum greenei is native to California (recorded as native).
When does Crocanthemum greenei bloom?
Crocanthemum greenei blooms Apr-May.
Where in California does Crocanthemum greenei grow?
Crocanthemum greenei occurs in Los Angeles, Santa Barbara, at elevations of < 500 m.
What plant family does Crocanthemum greenei belong to?
Crocanthemum greenei is in the Cistaceae family, genus Crocanthemum.
Is Crocanthemum greenei rare or endangered?
Crocanthemum greenei carries California Rare Plant Rank 1B.2, state rank S3.
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.