Onopordum is a genus of plant that includes about 40 different species. All species of Onopordum are thistle plants and are biennial in nature, which means they flower for two seasons before dying. The plants are found natively in a number of regions, including Europe, parts of Asia and North Africa. Other common names for the genus include Scotch and Cotton thistle.
The plants vary in size, depending on the species, with the largest growing to around 10 feet (3 meters). Typically, however, the plants are much smaller than this. The plants usually don’t have a large number of flowers during the first season, but flower to a greater extent during the second. After the second season, the plants usually die; there are, however, several species which are perennial, meaning they flower for more than two seasons. The leaves of the plants are strong and contain a number of spines, which gives the plant’s their distinctive, spiny appearance.
In order to propagate, Onopordum plants only use seeds. During the middle of summer the seeds are released. The seeds are rough and have a number of ridges.
Onopordum plants are important for a number of animals in the food chain. For example, certain larvae use the species exclusively for food. There is at least one species, found in Greece, which is eaten by humans.
A common species is Onopordum acanthium, which is sometimes known as cotton thistle, and is a flowering plant. This species is natively found all over Europe and some parts of Asia, but is now common in a number of other places as well. The flowers of the cotton thistle are shaped like globes and are dark pink.
Another common species is Onopordum Illyricum, which is native to Europe, but now grows in many places around the world, including Australia. The plant is considered to be an invasive weed in most places. Each flower is relatively small and purple in color. The species is sometimes known as the Illyrian thistle as well.
Other species include the Onopordum acaulon, amerenum and tauricum. The tauricum species is also known as the Turkish thistle and is natively found in Europe, but has spread to the US. The species is a noxious weed, which means that it’s invasive and damaging to native plants. Usually, the plant grows to around 6 feet (approximately 2 meters) in height and has pink flowers.