|Butterfly on Eutrochium maculatum 'Gateway'|
There are three different species of Eutrochium (all formerly considered part of Eupatorium) in Georgia. The common name “Joe Pye weed” comes from a story that a Native American named Joe Pye used the leaves of it to brew a tonic that helped people with fevers in the late 1700’s or early 1800’s. Four species are found in New England, where the story originates, so it’s not clear which species might have been used.
|Eutrochium purpureum (purple at the node)|
Spotted Joe Pye weed (Eutrochium maculatum) is limited in its natural range in Georgia with reports of it being found only in Murray and Union counties (in the Blue Ridge ecoregion). The reddish, sometimes spotted stem is characteristic of this species; it also generally reaches up to 6 feet tall. Other differences include the number of florets per head being more numerous (9-22 per head) and the overall inflorescence shape being more flat than dome-shaped (good pictures here). I think the flower color is generally a deeper pink as well. This is the species from which the shorter cultivar ‘Gateway’ was developed; that cultivar is said to be 4-5 feet tall. I have found that it does well in pots if kept moist.
|Eutrochium fistulosum with hollow stem|
Florets are fewer than maculatum, usually 5-7 per flower head, but the inflorescence itself is large and dome shaped. Flower color varies from pale to medium pink.
with florets open
|Eutrochium maculatum with about 11 florets per flower head.|
Other E. maculatum cultivars besides ‘Gateway’ include ‘Atropurpureum’ and ‘Phantom’ as well as a few others. E. dubium ‘Little Joe’ and ‘Baby Joe’ are both from a species native to the coastal areas of the East Coast. E. fistulosum cultivars include ‘Carin’ plus others, including some white selections such as ‘Bartered Bride’ and ‘Ivory Tower.’
You can read about Eupatorium “family” plant trials in Chicago in a report published here in 2014. It includes names of cultivars and detailed descriptions but the recommendations may not be as appropriate for Georgia.