Cocklebur
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| Xanthium | ||||||||||||
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| Missing image Xanthium_strumarium_L..jpg | ||||||||||||
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The Cockleburs are flowering plants of the genus Xanthium, part of the daisy family Asteraceae. They are course, herbaceous annual plants that produce seeds in the form of hard, spiny, football-shaped burs that stick to fur and clothing and can be quite difficult to extract.
Cockleburs produce two kinds of flowers. One kind, in short terminal branches, produces only pollen. The other kind, in clusters in the axils of the leaves, produces seed.
The seeds are typically enclosed in a one-seeded fruit, called an achene. Unlike many other members of the family Asteraceae, whose seeds are airborne with a plume of silky hairs resembling miniature parachutes, the achene of the cocklebur are enclosed in a small, hard, double-chambered, oval bur about 3/4" long. It is covered with stiff, hooked spines. This plant reproduces only by means of its seed. These remarkable burred seeds have allowed this plant to be carried all over the world by unsuspecting travelers.
Cockleburs are short-day plants, meaning they only flower when the nights are long. They can bloom in the tropics where the days are short and the nights are long, thus greatly increasing their range and potential for seed production. In North America, cockleburs typically bloom during the fall months when the days are shorter and the nights longer. They will not bloom during the long days of summer or near a street light.
Dangers and uses
The Common Cocklebur (X. strumarium) is a native of North America that has become a noxious weed worldwide. It invades agricultural lands and can be poisonous to livestock. Some domestic animals will avoid consuming the plant if other forage is present, but less discriminating animals, such as pigs, will consume the plants and then sicken and die. Seedlings and seeds are the most toxic parts of the plants.
The plant also has been used for medicinal properties and for making yellow dye. The many species of this plant, which can be found in many areas, may actually be varieties of two or three species.
There are two other interesting uses for cockleburs. Because they readily attach to cloth material, they can be used as "darts" in a cocklebur dart game. Also, sixteen of the spiny burs can be glued together to form a perfect little poodle dog.
Some Xanthium species
- X. canadense - Probably a variety of X. strumarium.
- X. commune -
- X. chinense - Probably a variety of X. strumariumm.
- X. echinatum -
- X. glabratum - X. strumarium var. glabratum.
- X. inflexum -
- X. italicum - Probably a variety of X. echinatum.
- X. occidentale - Noogoora burr
- X. sibiricum -
- X. speciosum -
- X. spinosum - Spiny clotbur, Burreed, Bathurst burr.
- X. strumarium - Cocklebur, Clotbur, Rough cocklebur, Large cocklebur, Common Cocklebur.
References
- Robbins, W.W., M.K. Bellue and W.S. Ball. Weeds of California. State Department of Agriculture, Sacramento, California (1941).lt:Dagišius