Conoclinium coelestinum
Blue Mistflower, mistflower, hardy ageratum, wild ageratum
Description: perennial
Place of origin: eastern United States
Urban habitat: commonly found in moist soils along streams, in flood plains, drainage ditches, ravines, roadsides, railroads, in disturbed sites; thrives in full sun.
Ecological function: disturbance-adapted colonizer; food and habitat for wildlife.
History: Although native to the US, Conoclinium coelestinum is often considered weedy due to its tendency to spread quickly.