Xanthium strumarium, Rough Cocklebur
Scientific Name: Xanthium strumarium
Common Name: Rough Cocklebur
Also Called: Canada Cockleburr, Cocklebur, Cockleburr, Common Cocklebur, Rough Cockleburr (Spanish: Cadillo)
Family: Asteraceae, Sunflower Family
Synonyms: (Xanthium 17 species, Xanthium californicum 4 varieties, Xanthium strumarium ssp. italicum)
Duration: Annual with a taproot.
Size: Usually about 2 feet but may reach 5 feet.
Growth Form: Forb/herb; woody; erect, stems fleshy, rigid, rough and covered with stiff short hairs; stems with dark purplish spots or blotchy lines.
Leaves: Green; alternate; petioles up to 6 inches long; triangular or slightly lobed, 3 distinct veins; sharply toothed; glandular, stiff hairs.
Flower Color: Inconspicuous green flowers; monecious; male florets sessile on tips of short branches; female florets single or in clusters in leaf axils; fruit is a barrel shaped bur, an achene, yellowish brown, about 1 inch or more and covered with strong sharp hooked prickles.
Flowering Season: July to October.
Elevation: To 6,000 feet.
Habitat Preferences: Waste lands or disturbed areas, riverbanks, creeks, roadsides and low lying water holding areas, alluvial soil.
Recorded Range: Throughout the United States, including Puerto Rico and the Virgin Islands, Canada, Mexico and in central and south America. Introduced in Hawaii and invasive almost worldwide. Found throughout Arizona.
North America & US County Distribution Map for Xanthium strumarium.
U.S. Weed Information: Xanthium strumarium is listed in 46 states and in: Weeds of Kentucky and adjacent states: a field guide, Weeds of the Northeast, Weeds of Nebraska and the Great Plains, Southeast Exotic Pest Plant Council of Tennessee, Weeds of the United States and Canada, and Weeds of the West. Plants included here may become weedy or invasive.
Invasive/Noxious Weed Information: Xanthium strumarium is listed as a Noxious weed by the state of Arkansas and is listed as a Secondary noxious weed by the State of Iowa. Plants included here are invasive or noxious.
Wetland Indicator: Xanthium strumarium is on the USDA 2012 National Wetland Plant List.
Threatened/Endangered Information: No data available.
Xanthium strumarium var. canadense, Canada Cocklebur (AZ);
Xanthium strumarium var. glabratum, Rough Cocklebur and
Xanthium strumarium var. strumarium, also Rough Cocklebur.
Comments: The clingy hooked burs of Common Cocklebur easily catches on fur and clothing and is difficult to remove. Through this clever method the seeds are dispersed across large areas unwittingly by animals and human travelers. Common Cocklebur is a highly variable species and is considered a troublesome weed throughout the United States.
Common Cocklebur has ethno botanical uses See the complete species account from Native American Ethnobotany, University of Michigan, Dearborn.