Eupatorium coelestinum 'Wayside Variety' is derived from a perennial native to the eastern half of the United States that closely resembles Ageratum. Wayside Variety mistflower grows up to 15 inches in height and features sky-blue flowers that attract butterflies but repel deer. A great perennial for Chicago area gardeners, this plant is tolerant of wet clay soils and blooms from mid-summer through fall.

The genus name refers to Eupator, King of Pontus, who used one species as an antidote for poison. Eupatorium coelestinum is another member of the Asteraceae, or sunflower family, that lacks the typical showy ray flowers (what we refer to as "petals"), but it more than makes up for the loss with very colorful disk flowers.