Cocklebur
Scientific Name: Xanthium strumarium L.
Other Names: lampourde glouteron, Bur, Clotbur, glouteron
Family: Composite or Aster Family (Compositae)
General Description: Annual, reproducing only by seed.
Habitat: Occurs throughout Ontario. Present in and around farmyards, in fields, along roadsides and river flats. Common in low areas. Common in fine-texture soils (clays, clay loams).
Seedlings
- Leaves are long, narrow, smooth
- 2 first leaves are opposite (2 per node), successive leaves are alternate (1 per node)
Stems
- Erect, usually much-branched
- 30- 120 cm (12- 48 in.) high
- Rough-hairy often with lengthwise ridges and spotted
Leaves
- Stalked
- Oval or triangular
- Somewhat angular heart-shaped at the base
- Edges of the lowermost main branching veins usually exposed in a broad V or M
- Margins are coarsely toothed
- Surfaces are harsh or rough-hairy
- Lower leaves opposite (2 per node); upper leaves alternate (1 per node)
Flowers
- Flower heads clustered in axils of leaves and at ends of branches
- Sexes in separate heads but both sexes on the same plant
- Heads of male flowers small, spherical, not spiny
- Heads of female flowers are larger, become very hard and woody, covered with slender, hooked spines and terminating in 2 hard, hooked, beak-like spines and turn brown at maturity
- Flowers from August to October
Often Confused With
Giant Ragweed (Leaves of cocklebur are mostly alternate while the leaves of giant ragweed are opposite.)
Caution: Seedlings of Cocklebur are poisonous to livestock, especially to young pigs which seem to relish their taste.