Euphorbia prostrata
Prostrate sandmat, Prostrate Sandmat
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Euphorbiaceae · Type: Herb · Not Native
Euphorbia prostrata (Prostrate sandmat) is a non-native California herb in the Euphorbiaceae family, recognized by toothed leaf margins distinctive among prostrate species.
Prostrate sandmat is a naturalized annual found in southern California floristic province in disturbed areas at elevations below 1,000 meters. Flowering from June to November, this plant produces white petal-like appendages surrounding tiny clusters of flowers. Growing with prostrate stems that repeatedly fork and spread horizontally, reaching up to 10 to 15 centimeters long and typically two-faced in appearance. Its opposite leaves are small, ranging 3 to 11 millimeters long, ovate to elliptic with fine teeth and slightly asymmetric bases. The fruit is a small spherical structure less than 1.5 millimeters wide, covered in fine hairs.
Identification and appearance
Key characters: 28 sympatric species; toothed leaf margins distinctive among prostrate species
Habitat and range
Habitat: Disturbed areas
Elevation: < 1000+ m
California counties: Los Angeles, Riverside, Ventura, San Bernardino, Sacramento, San Luis Obispo, Kern, Tuolumne, Alameda, San Joaquin, Marin
Outside California: to eastern United States, native to West Indies, S America
Bloom period
Euphorbia prostrata blooms Jun-Nov.
How to tell it apart
vs Croton: Euphorbia bleeds milky white latex and packs its flowers into a tiny cup (cyathium) rimmed with nectar glands; Croton has watery sap, stellate or scaly hairs, and ordinary small separate male and female flowers.; vs Stillingia: Euphorbia flowers sit in a gland-bearing cyathium; Stillingia bears its flowers in a spike with a pair of glands flanking each subtending bract and has no cyathium cup.; vs Ditaxis: Euphorbia has latex and the cyathium; Ditaxis has clear sap, 5-parted petaled male and female flowers, and 2-forked (malpighiaceous) hairs.; vs Asclepias: Both ooze milky sap, but Euphorbia's minute flowers cluster in a cyathium and ripen into a 3-lobed capsule; milkweeds have showy 5-parted flowers with a crown and paired follicles of plumed seeds.; vs Polygonum: Prostrate mat spurges leak milky sap when torn and have paired stipules with opposite leaves at the nodes; knotweeds have clear sap and a papery sheath (ocrea) wrapping each node.
Frequently asked questions
Is Euphorbia prostrata native to California?
No. Euphorbia prostrata is not native to California (recorded as not native).
When does Euphorbia prostrata bloom?
Euphorbia prostrata blooms Jun-Nov.
Where in California does Euphorbia prostrata grow?
Euphorbia prostrata occurs in Los Angeles, Riverside, Ventura, San Bernardino, Sacramento, San Luis Obispo, Kern, Tuolumne and other counties, at elevations of < 1000+ m.
What plant family does Euphorbia prostrata belong to?
Euphorbia prostrata is in the Euphorbiaceae family, genus Euphorbia.
What habitat does Euphorbia prostrata grow in?
Euphorbia prostrata grows in Disturbed areas.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
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.