Rough cocklebur (Xanthium strumarium)

Synonyms: Xanthium americanum, Xanthium chinense, Xanthium cylindraceum, Xanthium echinatu, Xanthium pensylvanicum

Common Names: Common cocklebur

Description: Considered a nuisance to livestock producers. This place can reduce the value of wool if burs are entangled and is considered poisonous to all livestock. This species is listed under Regulation No. 715 - Seed Law Implementation as a restricted noxious weed by the Michigan Department of Agriculture.

Habit: Coarse, erect, branching, annual herb that reproduces solely by seed.

Leaves: First true leaves are opposite, subsequent leaves are alternate. Triangular to ovate, covered with stiff hairs, 2-6 inches long with irregular lobes and leaf margins with inconspicuous teeth.

Stems: Erect, reaching heights of 30-150 cm tall, tough, covered with dark streaks or spots and short hairs.

Flowers: Inconspicuous, greenish in color, arising between the leaf petioles and the stems and at the ends of the erect stems.

Fruit and seeds: Elliptic to egg-shaped two-chambered bur, 0.5-1.5 inches long and covered with hooked prickles. Each contain 2 seeds and 2 hooks project from the tip of the bur that are longer and winder than the others.

Habitat: Native to North America. Can be found in roadsides, railways, small streams, and riverbanks.

Reproduction: Reproduces only by seed.

Monitoring and rapid response: Hand-pulling or hoeing is effective for small populations prior to flowering. Prescribed burning has been shown to be effective in destroying seed bank. Can be controlled using a wide variety of soil- and foliar- applied herbicides such as 2,4-D amine, Dicamba, Bromoxynil and selective weed oils.

Credits: The information provided in this factsheet was gathered from CABI: Invasive Species Compendium and the Bugwood Wiki.

Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org). Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).

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