Carduus nutans is a biennial plant in the daisy and sunflower family Asteraceae with the common names musk thistle, nodding thistle, and nodding plumeless thistle. It is native to regions of Europe, Central Asia, and North Africa, where it is a scattered pasture plant. The musk thistle has been declared as invasive in North America, Australia, New Zealand, and South Africa. Mature plants can reach in height with multi-branched stems. The leaves are prickly and jagged and can reach up to in length. The leaves are dark green, coarsely bipinnately lobed, with a smooth, waxy surface and sharp yellow-brown to whitish spines at the tips of the lobes. They are more or less hairy on top, and wooly on the veins below. The stem is cottony/hairy, <small><big>with thin ribs along them.</big> A single plant is able to produce around 100 seeds per flower, up to about 20,000 seeds per plant. It has become invasive in North America, Australia, New Zealand, and Southern Africa. It has also been documented that it has been used for treatment of liver disease, malaria, constipation, and kidney stones.
Ecology
Climate and habitat play a large role in phenology of Carduus nutans. Classified as a biennial, it can also act as a summer or winter annual, as well as a perennial, depending on varying environmental conditions. It is declared a noxious weed in many U.S. states, Canadian provinces, South Africa, New Zealand, and Australia. The plant is especially fertile, producing up to 20,000 seeds per plant, Pastures and rangelands suffer from decreased productivity and the sharp spines of the plant make an unsuitable grazing area for livestock. In the United States there has been success with Rhinocyllus conicus, Trichosirocalus horridus, and Puccinia carduorum. When biological control is successful, natural plants are shown to return to the habitat.