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Federal Noxious Weed TDA Noxious Weed TPWD Prohibited Exotic Species 
Invasive Plant Atlas of the USNOTE:
means species is on that list.
Xanthium spinosum
Spiny cocklebur
Synonym(s): Xanthium spinosum var. inerme,
Acanthoxanthium spinosum, spiny cockleburr,
Bathurst burr, cocklebur, spanish-thistle, daggerweed, spiny burweed, thorny burweed
Family: Asteraceae (Aster Family)
Duration and Habit: Annual Herb
Photographer: Russ Kleinman, Tyrone, McKinney Rd., Oct. 3, 2007
Source: Western New Mexico University Department of Natural Sciences
Description
Xanthium spinosum is an erect, rigid, multi-branched annual herb, up to 1 m tall but grows up to 1.5 m or more wide. Stems are yellow to brown, and striated. Lhe leaves are gray-green and glabrous above and silvery on the underside with a white mid-rib and very short petioles that measure about 1 cm. Leaves vary by being lanceolate, entire, toothed or lobed, 3-8 cm long and 6-26 mm wide. Each leaf base has yellow, three-pronged spines that are approximately 2-5 cm long, often opposite in pairs. Flower heads are in axillary clusters or often solitary with green and inconspicuous flowers. MAle and female flowers are different with Male flowers as globular heads in axils of upper most leaves, and female flowers in axils of lower leaves, developing into a bur. The bur is two-celled, oblong, slightly flattened, 10-13 mm long, 4 mm wide, pale yellowish, glandular, covered with slender, hooked, glabrous spines, with the two apical beaks short and straight. Each bur contains two flattened, thick-coated, dark brown or black seeds, the lower germinating first.
Native Lookalikes: Currently no information available here yet, or there are no native Texas species that could be confused with Spiny cocklebur.
Ecological Threat: Xanthium spinosum can quickly overtake an area due to prolific seed production and high germination and survival rates. The presence of two seed types in each bur also increases its spread. Xanthium species are toxic to most domestic animals, particularly swine and horses. The poisonous compound, carboxyatractyloside, is present in seeds. This usually isn’t a problem as spiny burs are not palatable to animals. Poisoning generally results when these leaves are eaten. The plants establish most often at the edges of ponds, lakes, floodplains, or other bodies of water where shallow flooding followed by recession of the waterline occurs.
Biology & Spread: Xanthium spinosum was probably spread by clinging to the hair or wool of animals, to clothing, or to feed sacks, muddy tools, etc. The seeds are sometimes dispersed in impure seed stocks and in weedy hay. The seeds float and can be moved around by water.
History: Xanthium is derived from the Greek, xanthos, which means "yellow." It is thought that yellow dye was obtainable from some species, giving it its name. X. strumarium. Spiny clocklebur was introduced to California, probably by way of Europe, sometime before 1870. In Argentina, Xanthium spinosum has reportedly been used as a medicinal plant.
U.S. Habitat: Spiny cocklebur is a weed of open areas and waste places. The plant grows along roads, in pastures, meadows, roadsides and disturbed areas. It is sometimes common around waterholes and along floodplains, canals, ditches, creek flats, river terraces, and other moist places.
Distribution
U.S. Nativity: Introduced to U.S.
Native Origin: South America
U.S. Present: AL, AZ, CA, CO, CT, DC, DE, FL, GA, IA, ID, IL, IN, KS, KY, MA, MD, ME, MI, MO, MS, MT, NC, NE, NH, NJ, NM, NV, NY, OH, OR, PA, RI, SC, TN, TX, UT, VA, WA, WV
Distribution in Texas: Most reports in West Texas and Edwards Plateau regions with spare reports in Orange, TX.
Mapping
Invaders of Texas Map: Xanthium spinosum
EDDMapS: Xanthium spinosum
USDA Plants Texas County Map: Xanthium spinosum
Native Alternatives
X. strumarium, spiny clotbur has conspicuous narrower leaves tapering at both ends, short petioles, conspicuous three-pronged spines at the leaf base, and egg-shaped burs covered with hooked, thorny prickles.
Management
Manual & Mechanical: Hand pulling or hoeing is effective if done prior to flowering. Seeds can remain dormant in the soil for several years so the areas should be checked periodically. Burning: Prescribed burning is an effective means to destroy Xanthium spinosum seeds.
Biological: Most of the insect associates of Xanthium in California are polyphagous species. Twenty-one species have been found associated with spiny cocklebur in southern California. Oedopa sp. is probably the only insect species worthy of study as a potential biocontrol agent for this plant.
Chemical: Herbicides commonly used for the control of broad-leaved weeds can be effective on controlling Xanthium spinosum. 2,4-D is a phenoxy-type herbicide that can be used.
Text References
Parsons, W.T. 1973. Noxious weeds of Victoria. Inkata Press, Ltd., Melbourne, Australia. 300 pp.
Pitcher, Don. (Dec 2013). http://wiki.bugwood.org/Xanthium_spinosum
Online Resources
USDA-Plants Database. http://plants.usda.gov/core/profile?symbol=xasp2
https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.56863
Search Online
Google Search: Xanthium spinosum
Google Images: Xanthium spinosum
NatureServe Explorer: Xanthium spinosum
USDA Plants: Xanthium spinosum
Invasive Plant Atlas of the United States: Xanthium spinosum
Bugwood Network Images: Xanthium spinosum
