September 24, 2014
I doubt I'd ever plant White Snakeroot (Ageratina altissima) on purpose. Never say never, of course, but this one is deadly poisonous for most mammals, including humans. White Snakeroot--also known as Richweed, Tall Boneset, and White Sanicle--is blamed for the death of Abraham Lincoln's mother, after she drank the milk from a cow that had consumed a toxic amount of this plant. The poisonous compound it contains is tremetol, according to the University of Illinois at Urbana-Champaign.
I've noticed plenty of White Snakeroot this growing season--on hikes, on roadsides, and in the open edges of woods on our property. Just as I wouldn't plant it intentionally, I wouldn't pull it either, because it's a valuable source of nectar for many bees and other pollinators--in late fall, when most other flowers have faded.
Every photo I've taken of White Snakeroot includes pollinators--big, small, and everything in between. The Xerces Society labels it a plant that supports biological control, which means it attracts predatory or parasitoid insects that help keep pest insects in check. The round heads of the plant's white flowers are arranged in clusters--giving pollinators easy access.
White Snakeroot is native to most of the eastern U.S. and Canada, according to the Lady Bird Johnson Wildflower Center. It grows in moist or dry soil, and has a high tolerance for drought. It prefers sun or part shade, at the edges of woods or thickets. A perennial, it grows 1-3 ft. tall.
I'll be curious to hear your thoughts about this plant. It seemed like a natural to highlight for Wildflower Wednesday because it's a native wildflower and is beneficial to pollinators. I know other garden bloggers have posted about it in the past, and the reviews have been mixed.
Here in Southern Wisconsin, White Snakeroot is keeping good company with other late-blooming native wildflowers, including the Goldenrods and Asters. I have to admit the flowers are pretty. I still wouldn't plant it intentionally ... but I wouldn't remove it either.
Thanks to Gail at Clay and Limestone for hosting Wildflower Wednesday!