Euphorbia polycarpa
Smallseed sandmat, Smallseed Sandmat
Photo by Chez Brungraber
Family: Euphorbiaceae · Type: Herb · Native
Euphorbia polycarpa (Smallseed sandmat) is a native California herb in the Euphorbiaceae family, recognized by perennial habit and variable appendages.
Smallseed sandmat is a California native perennial found in southwestern deserts and desert regions on dry, sandy slopes and flats at elevations below 1,000 meters. Flowering throughout the year, this plant produces white to red petal-like appendages surrounding tiny reddish to black glands in small cyathia clusters. Growing with prostrate to ascending stems that repeatedly fork and spread in a two-faced pattern, it forms low-growing patches across sandy terrain. Its opposite leaves are small, measuring 1 to 10 millimeters long, with round to ovate blades that have asymmetric bases and acute to obtuse tips. The fruit is a small, spherical, lobed structure producing white to light brown seeds that are ovoid and four-angled.
Identification and appearance
Key characters: 35 sympatric species; perennial habit and variable appendages
Habitat and range
Habitat: Common. Dry, sandy slopes and flats
Elevation: < 1000 m
California counties: San Diego, Riverside, San Bernardino, Los Angeles, Orange, Imperial, Inyo, Ventura, Sonoma, Kern
Outside California: Nevada, Mexico
Bloom period
Euphorbia polycarpa blooms All year.
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 polycarpa native to California?
Yes. Euphorbia polycarpa is native to California (recorded as native).
When does Euphorbia polycarpa bloom?
Euphorbia polycarpa blooms All year.
Where in California does Euphorbia polycarpa grow?
Euphorbia polycarpa occurs in San Diego, Riverside, San Bernardino, Los Angeles, Orange, Imperial, Inyo, Ventura and other counties, at elevations of < 1000 m.
What plant family does Euphorbia polycarpa belong to?
Euphorbia polycarpa is in the Euphorbiaceae family, genus Euphorbia.
What habitat does Euphorbia polycarpa grow in?
Euphorbia polycarpa grows in Common. Dry, sandy slopes and flats.
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.