Xanthium spinosum
Encyclopedia
Xanthium spinosum is a species of flowering plant in the aster family
known by many common names, including spiny cocklebur and prickly burweed. It is known worldwide as a noxious weed that grows in many types of disturbed habitat. Its original native range is not known but it may have come from South America
, possibly from Chile
. This is an annual herb producing a slender stem up to a meter tall or slightly taller. It is lined at intervals with very long, sharp, yellowish spines
which may exceed three centimeters in length and may divide into two or three separate spines. The leaves are divided into linear or lance-shaped lobes, the middle much longer than the others, and are arranged alternately all along the stem. Each is up to 10 or 12 centimeters long and dark green or grayish on top with a white underside. The plant produces male and female flower heads
, the female heads developing into bur
s one or 1.5 centimeters long and covered in thin spines. The spiny burs are easily dispersed
to new areas when they become attached to animals, people, and objects, or float on water. Bur damage to sheep's wool
reduces its value. The plants, especially new seedlings, are toxic
to livestock
.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
known by many common names, including spiny cocklebur and prickly burweed. It is known worldwide as a noxious weed that grows in many types of disturbed habitat. Its original native range is not known but it may have come from South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, possibly from Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
. This is an annual herb producing a slender stem up to a meter tall or slightly taller. It is lined at intervals with very long, sharp, yellowish spines
Thorns, spines, and prickles
In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...
which may exceed three centimeters in length and may divide into two or three separate spines. The leaves are divided into linear or lance-shaped lobes, the middle much longer than the others, and are arranged alternately all along the stem. Each is up to 10 or 12 centimeters long and dark green or grayish on top with a white underside. The plant produces male and female flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
, the female heads developing into bur
BUR
BUR may refer to:* Bur, a saying by Gucci Mane* Burs , a Germanic tribe* Bob Hope Airport, Burbank, California * Burmese language * Burkina Faso...
s one or 1.5 centimeters long and covered in thin spines. The spiny burs are easily dispersed
Biological dispersal
Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...
to new areas when they become attached to animals, people, and objects, or float on water. Bur damage to sheep's wool
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....
reduces its value. The plants, especially new seedlings, are toxic
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
to livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
.