Trumpetweed vs Sweetscented Joe Pye Weed
These species are frequently confused where their ranges overlap in the eastern and lower Midwestern U.S. Their inflorescences are similar, but they can usually be distinguished by characteristics of their stem, and often also by their height and number of leaves per whorl. E. purpureum prefers slightly drier, shadier habitats than E. fistulosum, but these species overlap more in habitat than some Eutrochium sp.
Trumpetweed (Eutrochium fistulosum) | Sweetscented Joe Pye Weed (Eutrochium purpureum) |
A tall perennial of moist, disturbed sites, native to the eastern and southeastern U.S; the tallest Eutrochium. | A tall perennial of partly-shaded areas, preferring drier and shadier conditions than other Eutrochium species. |
 Leaves of mature plants usually in whorls of 4-7, occasionally 8. Seedlings frequently have fewer leaves / whorl or even opposite leaves. Photo © Mason Heberling, CC BY 4.0. |  Leaves of mature plants usually in whorls of 3-4, occasionally 5. Seedlings also frequently have opposite leaves. Photo © megachile, Public Domain. |
 Stems often purple throughout, usually glaucous (covered in waxy whitish coating.) Photo © Lydia B, CC BY 4.0. |  Stems mostly green, but purple at the nodes, with purple extending onto petioles of adjacent leaves. Not glaucous. Photo © Mirko Schoenitz, Public Domain. |
 Averages much taller, to 11.5 feet. Photo © Nate Martineau, CC BY 4.0. |  Averages shorter, to 6.5 feet. Photo © Mary Crickmore, Public Domain. |
 Broader stem is hollow, with a large central cavity. Photo © Ken Kneidel, Public Domain. |  Stem, which is usually narrower, is not usually hollow, and if hollow, has only a narrow central cavity. Photo © Becky, Public Domain. |
References & External Resources
These short lists show only links helpful for ID. For a complete list of references and resources also covering other aspects of ecology, visit the links section of the full article on each plant, which is the first entry here.
