Bristly Snakeroot can refer to several different plants, most commonly Persicaria madagascariensis (a type of knotweed) or one of several species in the genus Ageratina, which are often referred to as "snakeroot" due to historical, though often incorrect, beliefs about their medicinal use for snakebites.
Persicaria madagascariensis: This plant is an actual "Bristly Snakeroot" as a common name. It belongs to the knotweed family (Polygonaceae).
