Euphorbia melanadenia
Red-gland spurge, Red-Gland Spurge
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Family: Euphorbiaceae · Type: Herb · Native
Euphorbia melanadenia (Red-gland spurge) is a native California herb in the Euphorbiaceae family, recognized by dark red/black glands are unique.
Red-gland spurge is a California native perennial found in southwestern and desert southern California regions on dry, stony slopes and flats at elevations below 1,300 meters. Flowering from December to May, this plant produces distinctive white petal-like appendages surrounding dark red to nearly black glands in small clusters. Growing with decumbent to ascending stems that repeatedly fork and develop a two-faced structure, it reaches modest heights with repeatedly branching stems. Its opposite leaves are small, two to nine millimeters long, ovate with asymmetric bases and acute tips, arranged in two distinct ranks along the stem. The fruit is a small, lobed, and tomentose ovoid structure about 1.5 to 2 millimeters long.
Identification and appearance
Key characters: 30 sympatric species; dark red/black glands are unique
Habitat and range
Habitat: Dry, stony slopes or flats
Elevation: < 1300 m
California counties: Los Angeles, Imperial, Riverside, San Diego, San Bernardino
Outside California: Arizona, Baja California
Bloom period
Euphorbia melanadenia blooms Dec-May.
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 melanadenia native to California?
Yes. Euphorbia melanadenia is native to California (recorded as native).
When does Euphorbia melanadenia bloom?
Euphorbia melanadenia blooms Dec-May.
Where in California does Euphorbia melanadenia grow?
Euphorbia melanadenia occurs in Los Angeles, Imperial, Riverside, San Diego, San Bernardino, at elevations of < 1300 m.
What plant family does Euphorbia melanadenia belong to?
Euphorbia melanadenia is in the Euphorbiaceae family, genus Euphorbia.
What habitat does Euphorbia melanadenia grow in?
Euphorbia melanadenia grows in Dry, stony slopes or 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.