Page authors: Don Knoke, David Giblin
Xanthium orientale
cocklebur, common cocklebur
Specimens
Photos

Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast

Habitat: Wet meadows, shorelines, and disturbed open areas where moist.

Flowers: July-October

Origin: Native

Growth Duration: Annual

Conservation Status: Not of concern

Pollination: Bees, flies, beetles, wasps

Description:
General:

Monoecious, coarse annual with alternate leaves, 1-5 dm. tall

Leaves:

Leaves broadly ovate to sub-orbicular, generally cordate or deltoid at the base, with long petioles and without spines.

Flowers:

Staminate heads uppermost, many-flowered; involucre of separate bracts; receptacle cylindric, chaffy; involucre of the pistillate heads completely enclosing the 2 flowers, forming a 2-chambered bur with hooked prickles; pappus none.

Fruits:

Achenes thick, solitary in the chambers of the bur.

Accepted Name:
Xanthium orientale L.

Synonyms & Misapplications:
Xanthium strumarium L.
Xanthium strumarium L. var. canadense (Mill.) Torr. & A. Gray
Xanthium strumarium L. var. glabratum (DC.) Cronquist
Xanthium strumarium L. var. oviforme (Wallr.) M. Peck
Xanthium strumarium L. var. pensylvanicum (Wallr.) M. Peck
Xanthium strumarium L. var. strumarium
Xanthium strumarium L. var. wootonii (Cockerell) W.C. Martin & C.R. Hutchins, invalidly published
Additional Resources:

PNW Herbaria: Specimen records of Xanthium orientale in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Xanthium orientale checklist entry

OregonFlora: Xanthium orientale information

E-Flora BC: Xanthium orientale atlas page

CalPhotos: Xanthium orientale photos

19 photographs:
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