Chylismia arenaria
Sand evening-primrose
Family: Onagraceae · Type: Herb · Native
Conservation status: CNPS 2B.2
Chylismia arenaria (Sand evening-primrose) is a native California herb in the Onagraceae family, recognized by perennial habit, dusk-opening flowers, and heart-shaped leaves.
Sand evening-primrose is a rare (CNPS 2B.2) California native perennial found in the southern Desert region in sandy washes, rocky slopes, and desert scrub at elevations below 430 meters. Flowering from March to April, this plant produces bright yellow flowers that open at dusk, with petals 8 to 20 millimeters long. Growing up to 180 centimeters tall with spreading hairs and an erect, bushy form, it has distinctive leaves with coarse, variable teeth. Its leaves are cordate-deltate, measuring up to 60 millimeters long with petioles less than 60 millimeters. The plant produces ascending, nearly straight cylindric fruits 30 to 44 millimeters long with small pedicels.
Identification and appearance
Key characters: 8 sympatric species; distinguished by perennial habit, dusk-opening flowers, and heart-shaped leaves
Habitat and range
Habitat: Sandy washes, rocky slopes, desert scrub
Elevation: < 430 m
California counties: Imperial, Riverside
Outside California: southwestern Arizona, northern Mexico (Sonora)
Bloom period
Chylismia arenaria blooms Mar-Apr.
Conservation status
CNPS 2B.2
How to tell it apart
vs Eremothera: Chylismia has yellow flowers; Eremothera has white, pink, or red flowers that open at night.; vs Camissonia: Chylismia leaves are mostly basal and dandelion-like; Camissonia has narrow leaves up the stem.; vs Camissoniopsis: Chylismia has dandelion-like basal leaves; Camissoniopsis has lance-shaped leaves along the stem.; vs Eulobus: Chylismia has basal dandelion-like leaves; Eulobus has elegant wand-like stems with red-flecked petals.; vs Oenothera: Chylismia has dandelion-like basal leaves; Oenothera is typically a robust tall plant with 4-lobed stigma.
Frequently asked questions
Is Chylismia arenaria native to California?
Yes. Chylismia arenaria is native to California (recorded as native).
When does Chylismia arenaria bloom?
Chylismia arenaria blooms Mar-Apr.
Where in California does Chylismia arenaria grow?
Chylismia arenaria occurs in Imperial, Riverside, at elevations of < 430 m.
What plant family does Chylismia arenaria belong to?
Chylismia arenaria is in the Onagraceae family, genus Chylismia.
Is Chylismia arenaria rare or endangered?
Chylismia arenaria carries California Rare Plant Rank 2B.2, state rank S2S3.
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.