Cleomella palmeri
Palmer's jackass-clover, Palmer's Jackass-Clover
(c) W. Terry Hunefeld, some rights reserved (CC BY), uploaded by W. Terry Hunefeld · licence
Family: Cleomaceae · Type: Perennial · Native
Conservation status: CNPS 2B.1
Cleomella palmeri (Palmer's jackass-clover) is a native California perennial in the Cleomaceae family, recognized by unique perennial habit with nutlet fruits.
Palmer's jackass-clover is a rare (CNPS 2B.1) California native perennial found in the southern desert region in sandy washes, dunes, and desert scrub at elevations below 130 meters. Flowering from April to November, this plant produces bright yellow flowers with elliptic petals 2.5 to 6.3 millimeters long. Growing with much-branched brown-gray stems up to 2 meters tall, it develops a short-lived but robust structure. Its distinctive leaves feature three leaflets below and a simple leaf above, with linear-elliptic leaflets 17 to 35 millimeters long. The fruit consists of two small nutlets, each 1 to 5.5 millimeters in length.
Identification and appearance
Key characters: 5 sympatric species; unique perennial habit with nutlet fruits
Habitat and range
Habitat: Sandy washes, dunes, desert scrub
Elevation: < 130 m
Outside California: northwestern Mexico
Bloom period
Cleomella palmeri blooms Apr-Nov.
Conservation status
CNPS 2B.1
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 palmeri native to California?
Yes. Cleomella palmeri is native to California (recorded as native).
When does Cleomella palmeri bloom?
Cleomella palmeri blooms Apr-Nov.
What plant family does Cleomella palmeri belong to?
Cleomella palmeri is in the Cleomaceae family, genus Cleomella.
Is Cleomella palmeri rare or endangered?
Cleomella palmeri carries California Rare Plant Rank 2B.1, state rank S1.
What habitat does Cleomella palmeri grow in?
Cleomella palmeri grows in Sandy washes, dunes, desert scrub.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.