Chromolaena

Chromolaena is a genus of flowering plants in the family Asteraceae, commonly known as tridax daisy or boneset. The genus comprises approximately 70 species, predominantly found in the tropical and subtropical Americas. Many species are herbaceous perennials, though some are shrubs or subshrubs. They are characterized by their opposite leaves, often toothed or lobed, and their flower heads which are typically clustered in terminal panicles. The flower heads usually contain numerous small florets, often white, pink, or purple.

One of the most well-known species is Chromolaena odorata, also known as Siam weed or devil weed. This invasive species has spread widely across tropical and subtropical regions globally, often outcompeting native vegetation and impacting biodiversity. In some regions, it is considered a significant agricultural and environmental pest. Despite its invasive nature, Chromolaena odorata has traditional medicinal uses in various cultures, with extracts being employed for wound healing and as an anti-inflammatory agent. Other species within the genus have varied ecological roles and are sometimes cultivated for ornamental purposes, though their widespread distribution and potential for invasiveness are common traits. Research continues into the phytochemical properties and ecological impacts of various Chromolaena species.