noun

• Any member of the genus Ageratina of perennials and rounded shrubs from the sunflower family, growing mainly in the warmer regions of the Americas.
• Any of various plants of other genera, including Eupatorium, Asarum canadense (Canadian snakeroot), Aristolochia serpentaria (Virginia snakeroot), Eryngium cuneifolium, Plantago major, Polygala senega (Seneca snakeroot), and Rauvolfia serpentina (Indian snakeroot).
• Bistorta officinalis (common bistort)