E-Flora BC: Electronic Atlas of the Flora of British Columbia

Xanthium strumarium var. canadense L. (Mill.) Torr. & A. Gray
common cocklebur (Canada cockleburr)
Asteraceae (Aster family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #14618)

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Distribution of Xanthium strumarium var. canadense
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Species Information

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General:
Annual herb from a taproot; stems erect, solitary, simple, stiff-hairy or nearly glabrous, 0.2-2 m tall.
Leaves:
Basal leaves lacking; stem leaves broadly egg-shaped to kidney-shaped, becoming heart-shaped at the base, alternate, sometimes shallowly 3- to 6-lobed, stalked, 2-15 cm long including the stalks, stiff-hairy or nearly glabrous.
Flowers:
Heads unisexual in several or many short, axillary clusters; male involucres of separate bracts, female involucres of fused bracts forming a conspicuous cylindric to egg-shaped 2-chambered bur with hooked prickles, 1-3.5 cm long; corolla lacking.
Fruits:
Achenes thick, solitary in the chambers of the bur; pappus lacking.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist ditches and disturbed areas in the steppe zone; rare in SC BC and SW BC (lower Fraser River valley); introduced from E North America.

Source: The Illustrated Flora of British Columbia

Climate

The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Xanthium acerosum Greene
Xanthium californicum Greene
Xanthium californicum var. rotundifolium Widder
Xanthium campestre Greene
Xanthium canadense Mill.
Xanthium cavanillesii Schouw
Xanthium cenchroides Millsp. & Sherff
Xanthium commune Britt.
Xanthium echinatum Murr.
Xanthium glanduliferum Greene
Xanthium italicum Moretti
Xanthium macounii Britt.
Xanthium oligacanthum Piper
Xanthium oviforme Wallr.
Xanthium pensylvanicum Wallr.
Xanthium saccharatum Wallr.
Xanthium speciosum Kearney
Xanthium strumarium subsp. italicum (Moretti) D. L÷ve
Xanthium strumarium var. oviforme (Wallr.) M.E. Peck
Xanthium strumarium var. pensylvanicum (Wallr.) M.E. Peck
Xanthium varians Greene

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References