Page authors: Don Knoke, David Giblin
Euphorbia glyptosperma
rib seed sandmat, corrugate seeded spurge, ridge seeded spurge

Distribution: Chiefly east of the Cascades in Washington; British Columbia south to California, east to Maine and Texas.

Habitat: Dry, sandy soil, from the plains to the lower mountains.

Flowers: June-September

Origin: Native

Growth Duration: Annual

Conservation Status: Not of concern


Monoecious, glabrous annuals with prostrate, freely-branching stems 0.5-4 dm. long.


Leaves opposite, obliquely lanceolate to oblong, 5-15 mm. long, entire or with fine, rounded serrations; stipules mostly linear, 1 mm. long.


Flowers tiny, monoecious, borne in axillary involucres; staminate flowers numerous, naked, each consisting of a single stamen; pistillate flower single and terminal in the involucre; involucre bearing 4 pinkish glands with whitish appendages, a fifth gland represented by a short, fringed lobe.


Capsules smooth, 1.5 mm. long; seeds 1.2 mm. long, grayish, prismatic, coarsely wrinkled.

Accepted Name:
Euphorbia glyptosperma Engelm.
Publication: Rep. U.S. Mex. Bound. 2(1): 187. 1859.

Synonyms & Misapplications:
Chamaesyce glyptosperma (Engelm.) Small [KZ99, JPM]
Additional Resources:

PNW Herbaria: Specimen records of Euphorbia glyptosperma in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Euphorbia glyptosperma checklist entry.

E-Flora BC: Euphorbia glyptosperma atlas page.

CalPhotos: Euphorbia glyptosperma photos.

USDA Plants: Euphorbia glyptosperma information.

21 photographs:
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