Xanthium strumarium (rough cocklebur, clotbur, common cocklebur, large cocklebur, woolgarie bur) is a species of annual plants of the family Asteraceae. Some sources claim it originates in southern Europe and Asia, but has been extensively naturalized elsewhere. Others, such as the Flora of China and Flora of North America, state it orignates in the Americas but was an early introduction to Eurasia.
The species is monoecious, with the flowers borne in separate unisexual heads: staminate (male) heads situated above the pistillate (female) heads in the inflorescence. The pistillate heads consist of two pistillate flowers surrounded by a spiny involucre. Upon fruiting, these two flowers ripen into two brown to black achenes and they are completely enveloped by the involucre, which becomes a bur. The bur, being buoyant, easily disperses in the water for plants growing along waterways. However, the bur, with its hooked projections, is obviously adapted to dispersal via mammals by becoming entangled in their hair. Once dispersed and deposited on the ground, typically one of the seeds germinates and the plants grows out of the bur.
Toxic or medicinal phytochemistry
However, while small quantities of parts of the mature plants may be consumed, the seeds and seedlings should not be eaten in large quantities because they contain significant concentrations of the extremely toxic chemical carboxyatractyloside. The mature plant also contains at least four other toxins.
- Animals have also been known to die after eating the plants.
- A patient consuming a traditional Chinese medicine containing cocklebur called Cang Er Zi Wan (苍耳子丸) developed muscle spasms.
- It was responsible for at least 19 deaths and 76 illnesses in Sylhet District, Bangladesh, 2007. People ate large amounts of the plants, locally called ghagra shak, because they were starving during a monsoon flood and no other plants were available. The symptoms included vomiting and altered mental states, followed by unconsciousness.
Xanthium strumarium – MHNT
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- BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
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- "Xanthium strumarium". Atlas of Florida Plants. Institute for Systematic Botany, University of South Florida.
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- Strother, John L. (2006). "Xanthium strumarium". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 21. New York and Oxford. Retrieved July 27, 2022 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Shi, Zhu. "Xanthium strumarium". Flora of China. Vol. 20–21. Retrieved July 27, 2022 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Weaver, S.E.; Lechowicz, M.J. (1982). The biology of Canadian weeds. 56. 'Xanthium strumarium' L. Canadian Journal of Plant Science.
- Kamboj Anjoo; Saluja Ajay Kumar (2010). "Phytopharmacological review of Xanthium strumarium L. (Cocklebur)". International Journal of Green Pharmacy. 4 (3): 129–139. doi:10.4103/0973-8258.69154.
- Islam MR, Uddin MZ, Rahman MS, Tutul E, Rahman MZ, Hassan MA, Faiz MA, Hossain M, Hussain M, Rashid MA (Dec 2009). "Ethnobotanical, phytochemical and toxicological studies of Xanthium strumarium L". Bangladesh Medical Research Council Bulletin. 35 (3): 84–90. doi:10.3329/bmrcb.v35i3.3658. PMID 20922910.
- West PL, Mckeown NJ, Hendrickson RG (May 2010). "Muscle spasm associated with therapeutic use of Cang Er Zi Wan". Clinical Toxicology. 48 (4): 380–4. doi:10.3109/15563651003610161. PMID 20521353. S2CID 25015169.
- Gurley ES, Rahman M, Hossain MJ, Nahar N, Faiz MA, Islam N, Sultana R, Khatun S, Uddin MZ, Haider MS, Islam MS, Ahmed BN, Rahman MW, Mondal UK, Luby SP (2010). "Fatal outbreak from consuming Xanthium strumarium seedlings during time of food scarcity in northeastern Bangladesh". PLOS ONE. 5 (3): e9756. Bibcode:2010PLoSO...5.9756G. doi:10.1371/journal.pone.0009756. PMC 2841199. PMID 20305785.