Devil's Rope Cactus, Bathurst Burr and Coral Cactus are some of the types of weeds that grow thorns. These particular examples are found in Australia but originate from a wide range of locations. Other thorny weeds such as Prickly Lettuce, are common worldwide.
Devil's Rope Cactus grows in certain parts of Australia and originates from the United States and Mexico, according to National Weeds Strategy. It is a branched cactus up to 3 meters high with a cylindrical trunk. Its spines, which can grow up to 3 centimeters in length, readily attach to skin and are difficult to remove. It is distinguishable by its rope-like segments. It can be controlled biologically using cochineal.
Bathurst Burr, native of South America, is distinguishable by 3-pronged hooked spines at the base of its leaves. Its seeds are poisonous to livestock and it routinely causes major problems and major damage to crops in Australian pastures, states the National Weeds Strategy website.
Coral Cactus, which originates from Arizona, grows small bristles in clusters, which attach to skin and are difficult to remove.
Some thorny weeds disperse by way of their seeds and must be handled with care, lest the seeds spread out during handling. Other weeds spread vegetatively by movement of segments that root where they contact the ground, says National Weeds Strategy.