Chromolaena odorata, commonly known as Siam weed, is native to the Americas. It is a fast-growing perennial shrub that produces clusters of small, lavender to light purple flower heads composed of numerous tubular florets with long, protruding styles. These blossoms form dense terminal clusters that can reach several inches across and are highly noticeable against the plant’s green foliage. This species is known for its rapid spread outside its native range, particularly in tropical Asia and Africa, where it has become an aggressive invader of farmland, forests, and disturbed areas. Within its native range in the Americas, however, Chromolaena odorata grows mainly in open fields, roadsides, and secondary forests. Ethnobotanical uses have been recorded, including traditional medicinal applications such as wound healing and treatments for skin infections, particularly in Africa and parts of Asia. Scientific studies have confirmed antimicrobial and anti-inflammatory properties in its extracts. Photographed in Florida.