| Author | Fernald | |
| Distribution | Northeastern Piedmont only; known from just four counties along the VA line.
Known only from central VA to north-central NC, but numerous in central and southern VA, barely extending into NC. | |
| Abundance | Rare to possibly uncommon and overlooked, within its small state range. This is a Significantly Rare species. | |
| Habitat | "Upland forests, woodland borders, marsh edges" (Weakley 2018). It typically grows in similar habitats as many other Piedmont Eupatorium species -- dry to mesic soils of wooded edges and openings, powerline clearings, etc. | |
| Phenology | Flowering and fruiting August-October. | |
| Identification | This species looks similar to a number of other thoroughworts, often reaching 3 feet tall with a wide-spreading inflorescence, but is told by its oddly toothed, paired leaves. Though they are lanceolate in shape like many others, the basal half is strongly serrated, whereas the terminal third to half is generally entire (or slightly serrated) and rather narrowly tapered to the apex. No other NC thoroughwort has such a narrowed and entire distal portion beyond a strongly serrated basal portion. | |
| Taxonomic Comments | The taxonomy of this plant is unsettled; it may ba a hybrid of E. altissimum x album. Molecular research is warranted. However, in VA it appears to act as a good species on its own accord, with a stable morphology; and with leaves that are narrower and more strongly serrated than both of these potential parent species, such a hybrid combination seems unlikely to those who have seen the species in the field.
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| Other Common Name(s) | Pasture Eupatorium, Tall Boneset, Tall Eupatorium | |
| State Rank | S1S2 | |
| Global Rank | G4 | |
| State Status | SR-L | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
