Snakeroot (Ageratina altissima)
Many plants are called Snakeroot because of their imagined powers to cure snakebite. This plant is as poisonous as the snakebite it is supposed to cure. All parts of it contain serious poisons. If ingested by cattle, the toxic substances are transmitted in milk. In the past, this caused the death of many people (including Abraham Lincoln's mother), but modern methods of milk preparation have remedied that situation.
This common perennial grows one to five feet tall. Its opposite, toothed leaves are lance-shaped and up to four inches long, each with a long petiole. The tubular flowers are white and in open branched clusters. It blooms from July through October in woodlands, thickets, clearings, damp and shady pastures, and fields throughout all the eastern half of the United States.
It was formerly known as (Eupatorium rugosum).