Ageratum
Ageratum, a garden plant. Some 30 species of ageratums are native to the warm parts of North and South America. The common garden ageratum, or floss flower, is an annual plant about three inches (7.5 cm) high, used to border gardens. The hardy ageratum, or mist flower, is a perennial plant about two feet (60 cm) high. Ageratums have numerous small, purple, blue, pink, or white flowers.ageratum, Eupatorium
The common garden ageratum is Ageratum houstonianum; the hardy coelestinum. Both are of the composite family, Compositae.