| Author | (L.) de Candolle | |
| Distribution | Coastal Plain and Piedmont; scarce in the Mountains. Some of the gaps in the Piedmont are likely to be filled with additional collecting. Seemingly absent from most of the Mountains, and in some counties may not be native. Many photos in iNaturalist from the Mountains are likely correct, but provenance of them is tricky, and these have not yet been added to the map.
NJ to IL and southeastern KS, south to southern FL and eastern TX; Cuba. Has been found farther north as escapes from cultivation. | |
| Abundance | Often common, and typically in dense patches, in the Coastal Plain. Infrequent to locally fairly common in the Piedmont, more numerous in the eastern portions. Very rare in the Mountains. Has increased in numbers in recent decades, seemingly spreading inland. | |
| Habitat | Wet to moist meadows, openings in floodplain forests and bottomlands, streamsides, roadside ditches. Can appear somewhat weedy at times. |
| Phenology | Flowering and fruiting late July-October. | |
| Identification | The unique lavender-blue color of Blue Mistflower separates it from our species of Ageratum and Eupatorium. Plants grow in patches from long horizontal rhizomes; leaves are opposite and ovate. There are no ray florets. Fleischmannia incarnata has pink florets and is a sprawling, long-stemmed plant of rocky slopes and woodlands, over high pH soil. | |
| Taxonomic Comments | In older texts treated as Eupatorium coelestinum.
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| Other Common Name(s) | Mistflower, Hardy Ageratum, Blue Boneset | |
| State Rank | S5 | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | FAC link |
| USACE-emp | FAC link |
