Page authors: Don Knoke, David Giblin
Euphorbia helioscopia
summer spurge, sun spurge, wart spurge, wartweed
Specimens
Photos

Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, east to the northern Rocky Mountains and northern Great Plains, Texas, and eastern North America.

Habitat: Weed of cultivated areas and abondoned gardens.

Flowers: April-July

Origin: Introduced from Eurasia

Growth Duration: Annual

Conservation Status: Not of concern

Pollination: Bees, wasps

Description:
General:

Somewhat fleshy annual, the upright stem 2-5 dm. tall, simple or occasionally branched below, umbellately branched near the top, nearly glabrous below but with dense, soft hairs above.

Leaves:

Lower cauline leaves alternate, oblanceolate, narrowed to the base, 1-3 cm. long, finely serrate-dentate; floral leaves opposite or whorled, finely toothed.

Flowers:

Flowers naked in obconic involucres, these bearing 4 greenish-yellow glands alternate with horn-less lobes; staminate flowers numerous, included in the involucre, represented by a single stamen; pistillate flower single, protruded from the involucre.

Fruits:

Capsule 3-celled, smooth.

Accepted Name:
Euphorbia helioscopia L.
Publication: Sp. Pl. 1: 459. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

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

WA Flora Checklist: Euphorbia helioscopia checklist entry

OregonFlora: Euphorbia helioscopia information

E-Flora BC: Euphorbia helioscopia atlas page

CalPhotos: Euphorbia helioscopia photos

5 photographs:
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