Xanthium strumarium

A second species of Xanthium, X. spinosum, is also reported from Louisiana. It can be differentiated from X. strumarium by the presence of three-parted spines at the base of the leaves.

The burs of Xanthium contain two seeds. In the field, the lower seed usually germinates the first year and the upper seed the second year (Arthur 1895). Dormancy in the upper seed can be overcome by removing the seed from the bur (Crocker 1906). Cocklebur may be controlled with herbecides and mowing. This is best done before seed set. Seedling identification: Cotyledons (seed leaves) waxy, smooth and thick with dark green upper surface. True leaves are dull green, paler below, rough hairs. Maroon to black lesions or markings on stem.

Tough and bitter, not palatable to cattle. Extremely poisonous in the two-leaf seedling stage.

The Acadian French name for cocklebur is "herb a' coquin," which literally means "rogue-plant" (Holmes 1990). Found throughout Louisiana and Texas in old fields, pastures, and disturbed areas. There are about 30 species of cockleburs in the western hemisphere, and they are all weedy. Cocklebur is poisonous, especially in the two-leaf stage. The plants become less poisonous and less palatable with age. The poisonous element is a glycoside called "xanthostrumarin." Fatal poisoning has occurred in cattle, sheep, hogs, and goslings. The symptoms are depression, weakness, unsteady gait, labored respiration, nausea, vomiting, rapid, and weak pulse, and low temperature. The effects of poisoning appear within one day after the plant is eaten and last a few hours (Philips Petroleum Company 1957).

Open fields, waste grounds, and especially drying sandy streambeds and floodplains.