Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

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Cirsium ochrocentrum, Yellowspine Thistle

Xanthium strumarium, Rough Cocklebur

Rough Cocklebur has small green flowers that are inconspicuous to the casual observer. Note here that the florets look similar to Ragweed flowers (Ambrosia). Xanthium strumarium Rough Cocklebur fruits are the familiar looking tan or yellow colored bur. At maturity the burs are covered with hooked prickles. Xanthium strumarium Rough Cocklebur inconspicuous flowers grow out from stem and leaf axils as shown here. Xanthium strumarium Rough Cocklebur has green leaves with long stalks, up to 4 inches - 10 cm long.  The somewhat rough leaves are covered with coarse or rigid hairs (not visible in photo). Xanthium strumarium Rough Cocklebur blooms and fruits from July to September or October. Rough Cocklebur in found in elevations from sea level to 6,000 feet (1,981 m). Xanthium strumarium Rough Cocklebur prefers waste lands or disturbed areas such as old fields, often in moist areas, floodplains, riverbanks, creeks, roadsides and low-lying water holding areas, alluvial soils.  Xanthium strumarium

Scientific Name: Xanthium strumarium
Common Name: Rough Cocklebur

Also Called: Canada Cockleburr, Canada Cocklebur, Cocklebur, Cockleburr, Common Cocklebur, Rough Cockleburr (Spanish: Cadillo)

Family: Asteraceae, Sunflower Family

Synonyms: (Xanthium, 17 species; Xanthium californicum, 4 varieties; Xanthium strumarium ssp. italicum)

Status: Native

Duration: Annual from a taproot.

Size: Usually about 2 to 3 feet (61-91 cm) but may reach 5 feet (152 cm) or more.

Growth Form: Forb/herb; stems upright (erect); stems with rough or like sand-paper, stiff, straight, closely appressed hairs or bristle (strigose).

Leaves: Green; leaves with long (up to 4 inches - 10 cm) stalks (petiole), blades typically broadly triangular (deltoid); leaves somewhat rough, covered with coarse or rigid hairs (hirtellous); leaves arranged alternately along the stem.

Flower Color: Green, floral heads inconspicuous; florets looking similar to those on ragweeds (genus Ambrosia), heads in clusters from axillaries; fruit a tan or yellow colored bur, burs covered with hooked prickles.

Flowering Season: July to September or October

Elevation: Sea level to 6,000 feet (1,981 m)

Habitat Preferences: Waste lands or disturbed areas such as old fields, often in moist areas, floodplains, riverbanks, creeks, roadsides and low-lying water holding areas, alluvial soils.

Recorded Range: Widely distributed throughout the United States, including Puerto Rico and the Virgin Islands, also common in Canada, Mexico and in central and south America. Common throughout the southwestern United States; largest populations in AZ, CA, NM, UT.

North America & US County Distribution Map for Xanthium strumarium.

North America species range map for Rough Cocklebur, Xanthium strumarium:

Rough Cocklebur, Xanthium strumarium: Click image for full size map
Click image for full size map

U.S. Wetland Indicator: In North America Xanthium strumarium has the following wetland designations:

  • Arid West, FAC
  • Atlantic and Gulf Coastal Plain, FAC;
  • Eastern Mountains and Piedmont, FAC;
  • Great Plains, FAC;
  • Midwest, FAC;
  • Northcentral & Northeast, FAC;
  • Western Mountains, Valleys, and Coast, FAC;

  • FAC = Facultative, occur in wetlands and non-wetlands

    Threatened/Endangered Information: Unknown

    U.S. Weed Information: In North America Xanthium strumarium is listed in 46 states; and can be weedy or invasive according to the following authoritative sources:

  • Weeds of Kentucky and adjacent states: a field guide,
  • Weeds of the Northeast,
  • Weeds of Nebraska and the Great Plains,
  • Invasive exotic pest plants in Tennessee
  • Weeds of the United States and Canada,
  • Weeds of the West.

  • Plants included here may become weedy or invasive.

    Invasive/Noxious Weed Information: Rough Cocklebur, Xanthium strumarium is listed as a Noxious weed by the state of Arkansas; and Canada Cocklebur, Xanthium strumarium var. canadense is listed as a Secondary noxious weed by the State of Iowa.

    Plants included here are invasive or noxious.

    International Invasive/Noxious Weed Information: 1The Centre for Agriculture and Bioscience International, (CABI), and 2The Invasive Species Compendium (ISC) has identified Xanthium strumarium is listed as an “Invasive Species, Pest and Host Plant”. Invasive almost worldwide.

    1The Centre for Agriculture and Bioscience International (CABI), Wallingford, Oxfordshire, England; The US Department of Agriculture is a lead partner with CABI.

    2The Invasive Species Compendium (ISC) is an encyclopedic resource that brings together a wide range of different types of science-based information to support decision-making in invasive species management worldwide.

    Genus Information: In North America there are 3 species and 3 accepted taxa overall for Xanthium. Worldwide, The Plant List includes 11 accepted species names and a further 79 scientific names of infraspecific rank for Xanthium.

    The genus Xanthium was published in 1753 by Carl Linnaeus, (1707-1778).

    In each of the Southwestern United States there is 1 native species of Xanthium and 1 introduced species. Data approximate, subject to revision.

    There are 3 varieties in Xanthium strumarium;
    Xanthium strumarium var. canadense, Canada Cocklebur;
    Xanthium strumarium var. glabratum, Rough Cocklebur;
    Xanthium strumarium var. strumarium, also Rough Cocklebur.

    Comments: One of the easy distinguishable features of Rough Cocklebur are the clingy hooked burs which easily catch 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, as noted elsewhere, is considered a troublesome weed throughout the United States and world.

    Importance to Wildlife, Birds and Livestock
    Rough Cocklebur, Xanthium strumarium has small almost inconspicuous flowers, although the flowers and their seeds may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of nectar or food.

    Rough Cocklebur, Xanthium strumarium has small almost inconspicuous flowers, although the flowers and their plants may be visited by butterflies, moths, flies, honeybees, Native Bees and other insects in search of food and nectar.

    U.S. Forest Service; Fire Effects Information System (FEIS)
    Click here for the U.S. Forest Service online collection of reviews of the scientific literature for management considerations of Rough Cocklebur, Xanthium strumarium.

    The genus “Xanthium” (Xanth'ium:) is from a Greek word meaning "yellow."

    The genus Xanthium was published in 1753 by Carl Linnaeus, (1707-1778).

    The species epithet strumarium (strumar'ium:) is of or pertaining to tumors or ulcers.

    Xanthium strumarium is used for a multitude of purposes by North American indigenous peoples.
  • Costanoan Drug, Urinary Aid; Decoction of seeds used for bladder ailments.
  • Lakota Drug, Ceremonial Medicine; Used as a medicine in ceremonies.
  • Paiute, Northern Drug, Oral Aid; Burs rubbed on sore gums to take the pain, poison and blood out.
  • Apache, White Mountain Drug, Blood Medicine; White Mountain Food, Bread & Cake; Roots and leaves used as a blood medicine and Seeds ground and used to make bread.
  • Costanoan Food, Staple; Seeds eaten in pinole.
  • Houma Drug, Febrifuge; Decoction of root taken for high fever.
  • Keres, Western Drug, Dermatological Aid; Western Other, Paint; Poultice of ground, seed powder used on open sores or saddle galls and Ground, seed powder used as a blue paint for the mask dancers.
  • Koasati Drug, Gynecological Aid; Decoction of roots taken to remove the afterbirth.
  • Mahuna Drug, Antirheumatic (Internal); Mahuna Drug, Kidney Aid; Mahuna Drug, Orthopedic Aid; Mahuna Drug, Tuberculosis Remedy; Mahuna Drug, Venereal Aid ; Plant used for rheumatism and Plant used for diseased kidneys and Plant used for total paralysis and Plant used for tuberculosis and Plant used for gonorrhea.
  • Navajo Drug, Dermatological Aid; Navajo, Ramah Other, Ceremonial Items; Plant used as a liniment for the armpit to remove excessive perspiration and Plant used to decrease perspiration and Leaf ash used as ceremonial blackening.
  • Pima Drug, Antidiarrheal; Pima Drug, Eye Medicine; Pima Drug, Laxative; Pima Drug, Veterinary Aid; Pima Other, Cooking Tools ; Decoction of burs taken for diarrhea and Pulp mixed with soot and used for sore eyes and Pulp used for sore eyes and Decoction of burs taken for constipation and Poultice of leaves applied to screw worm sores in livestock and Leaves used in roasting pits as containers for beans.
  • Rappahannock Drug, Dermatological Aid; Rappahannock Drug, Panacea; Decoction of seeds used as salve for sores and Compound decoction used for complaint.
  • Tewa Drug, Antidiarrheal; Tewa Drug, Antiemetic; Tewa Drug, Pediatric Aid; Tewa Drug, Urinary Aid; Plant used for diarrhea and Plant used for vomiting and Plant used as fumigant for children with urinary disorders and Plant used as fumigant for children with urinary disorders.
  • Zuni Drug, Ceremonial Medicine; Zuni Drug, Dermatological Aid; Zuni Food, Bread & Cake; Chewed seeds rubbed on body prior to cactus ceremony to protect from spines and Compound poultice of seeds applied to wounds or used to remove splinters and Seeds ground with corn meal, made into cakes or balls, steamed and used for food and Seeds ground, mixed with corn meal, made into pats and steamed.
  • Iroquois Drug, Witchcraft Medicine; Plant used in a witching medicine.

  • See complete listing of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.

    Date Profile Completed: 8/9/2012; updated 12/31/2020
    Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, as Xanthium saccharatum.
    U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search; accessed 12/31/2020.
    The Plant List (2013). Version 1.1. Published on the Internet;; accessed 12/30/2020.
    John L. Strother, FNA | Family List | FNA Vol. 21 | Asteraceae - Xanthium; 1. Xanthium strumarium Linnaeus, Sp. Pl. 2: 987. 1753.; Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford.
    Bruce G. Baldwin, adapted from Strother (2006) 2012, Xanthium strumarium, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on December 31, 2020.
    Uchytil, Ronald J. 1992. Xanthium strumarium. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [2020, December 30].
    Native Plant Information Network, NPIN (2013). Published on the Internet; accessed 12/31/2020. Lady Bird Johnson Wildflower Center at The University of Texas, Austin, TX.
    FNA 2006, Wiggins 1964, Kearney and Peebles 1969, Heil et al. 2013; Editors: S.Buckley 2010, F.S.Coburn 2015, A.Hazelton 2017; from SEINet Field Guide, on-line; accessed 12/31/2020.
    CABI, 2021. Xanthium strumarium [original text by Witt and Luke (2017):]. In: Invasive Species Compendium. Wallingford, UK: CAB International.
    Witt A, Luke Q, 2017. Guide to the naturalized and invasive plants of Eastern Africa. [ed. by Witt A, Luke Q]. Wallingford, UK: CABI. vi + 601 pp. DOI:10.1079/9781786392145.0000
    Seiler, John, Peterson, John, North American species range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
    SEINet synonyms, scientific names, geographic locations, general information.
    Etymology:Michael L. Charters California Plant Names: Latin and Greek Meanings and Derivations; A Dictionary of Botanical and Biographical Etymology - (accessed 12/30/2020)
    IPNI (2020). International Plant Names Index. Published on the Internet, The Royal Botanic Gardens, Kew, Harvard University Herbaria & Libraries and Australian National Botanic Gardens. [Retrieved 30 December 2020].