Conoclinium coelestinum, commonly called mistflower, is a late summer to fall-blooming herbaceous perennial that is native to the Eastern United States. It looks like annual ageratum and in that regard is sometimes commonly called hardy ageratum. But it is perennial and can spread aggressively by rhizomes. It typically grows to 1-2’ tall on downy purplish stems clad with coarsely-toothed, ovate-deltoid leaves (to 3” long). The flowers of this member of the aster family lack rays. Numerous small, fluffy, tubular, blue-purple flowers (to 1/ 2” across) with discoid heads bloom from July to October in dense flat topped terminal clusters (corymbs).
| Sun, Part Sun, Part Shade | |
| No | |
| 1.5-3 ft | |
| 1.5-3 ft | |
| Summer, Fall | |
| Yes | |
| Blue | |
| Yes |