Cleomella refracta
Jackass-clover
Photo by Chez Brungraber
Family: Cleomaceae · Type: Annual · Native
Conservation status: CNPS 2B.2
Cleomella refracta (Jackass-clover) is a native California annual in the Cleomaceae family, recognized by distinctive tall habit with nutlet fruits.
Jackass-clover is a California native annual found in southern Mojave Desert and northern Sonoran Desert in sandy washes, roadsides, and alkaline flats at elevations of 90 to 1,160 meters. Flowering from April to October, this plant produces bright yellow flowers in small dense racemes, with elliptic petals 1.5 to 4.5 millimeters long. Growing up to 2 meters tall with much-branched green to tan stems that spread widely from the base, it forms an open, sprawling structure. Its leaves are composed of three ovate leaflets 7 to 30 millimeters long, each about two to three times longer than wide. The small fruit develops into two nutlets, each measuring 1.2 to 3.3 millimeters in length.
Identification and appearance
Key characters: 11 sympatric species; distinctive tall habit with nutlet fruits
Habitat and range
Habitat: Sandy washes, roadsides, alkaline flats
Elevation: 90-1160 m
California counties: Riverside, San Bernardino, Kern
Outside California: to Utah, western Texas, Mexico
Bloom period
Cleomella refracta blooms Apr-Oct.
Conservation status
CNPS 2B.2
How to tell it apart
vs Physaria: Physaria has inflated bladder-like pods and 4 petals; Cleomella has small flat round capsules and variable petals.; vs Astragalus: Astragalus has compound leaves and pea-shaped flowers; Cleomella has palmately divided leaves and regular flowers.; vs Sesbania: Sesbania has pinnately compound leaves and large pea flowers; Cleomella has palmate leaves and small regular flowers.; vs Atriplex: Atriplex has tiny greenish flowers and simple leaves; Cleomella has showy flowers and palmately divided leaves.; vs Isocoma: Isocoma has yellow composite flower heads; Cleomella has individual flowers with separate petals and prominent stamens.
Frequently asked questions
Is Cleomella refracta native to California?
Yes. Cleomella refracta is native to California (recorded as native).
When does Cleomella refracta bloom?
Cleomella refracta blooms Apr-Oct.
Where in California does Cleomella refracta grow?
Cleomella refracta occurs in Riverside, San Bernardino, Kern, at elevations of 90-1160 m.
What plant family does Cleomella refracta belong to?
Cleomella refracta is in the Cleomaceae family, genus Cleomella.
Is Cleomella refracta rare or endangered?
Cleomella refracta carries California Rare Plant Rank 2B.2, state rank S1.
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 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.