Native Plant of the Week: White Snakeroot ~ Ageratina altissima

White Snakeroot ~ Ageratina altissima (Eupatorium rugosum)

White Snakeroot is in full bloom right now in the woodlands and woodland edges. A very common native perennial in our area, it is one of the first plants to emerge in a disturbed site. I've also seen it brightening darker woodlands that are mature and fairly undisturbed.

Formerly in the Joe Pye and Boneset genus Eupatorium, a recent reclassification of many plants in this genus has placed White Snakeroot in the Ageratina genus.
The round heads of white flowers are arranged in clusters. The flowers are sought out for nectar by many native bees, syrphid flies and wasps.

Very similar in appearance to Boneset (Eupatorium perfoliatum), the leaves being the distinguishing feature to tell the two apart. White Snakeroot leaves have stalks, and are rounder in shape, Boneset has stalkless lance shaped leaves.

White Snakeroot can reach heights of 3 to 3.5 feet, and widths of over 2 feet. It was an existing native perennial in my yard when we moved in, it self seeds yearly in different shaded to partly shaded spots.

If you have dry, poor soils in shade, White Snakeroot is a good candidate to try. It flowers from August into early October in our area, providing much needed color in late fall in woodlands.

White Snakeroot is native to northeastern North America. See map below for range.
Kartesz, J.T., The Biota of North America Program (BONAP).
North American Plant Atlas. Chapel Hill, N.C.