Genus Cirsium refers to a group of flowering plants commonly known as thistles. Thistles are known for their prickly leaves and beautiful flower heads that come in various shades of purple, pink, and white. Despite their notoriety as weedy pests, many species of Cirsium have significant medicinal and ecological value. There are many synonyms for the genus, depending on the region or classification system. Some popular synonyms for Cirsium include Carduus, Plume Thistle, and Bull Thistle. The genus belongs to the family Asteraceae, meaning they are related to daisies, sunflowers, and other similar plants.