Eutrochium is a genus of herbaceous flowering plants in Asteraceae. They are commonly referred to as Joe-Pye weeds. They are native to Eastern North America and have non-dissected foliage and pigmented flowers. It includes all the purple flowering North American species of the genus Eupatorium

Eupatorium

Eupatorium is a genus of flowering plants in the aster family, Asteraceae, containing from 36 to 60 species depending on the classification system. Most are herbaceous perennial plants growing to 0.5–3 m tall. A few are shrubs. The genus is native to temperate regions of the Northern Hemisphere....

as traditionally defined. Eupatorium has recently undergone some revision and has been broken up into smaller genera. Eutrochium is the senior synonym of Eupatoriadelphus. Eupatorium in the revised sense (about 42 species of white-flowered plants from the temperate

Temperate

In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 Northern hemisphere

Northern Hemisphere

The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

) is apparently a close relative of Eutrochium. Another difference between Eutrochium and Eupatorium is that the former has mostly whorled leaves and the latter mostly opposite ones. Eupatorium and Eutrochium are both placed in the subtribe Eupatoriinae, but South American plants which have sometimes been placed in that subtribe, such as Stomatanthes

Stomatanthes

Stomatanthes is a genus of about 15 species of plants primarily native to South America, but with three species native to Africa.- Classification :...

, seem to belong elsewhere in the tribe Eupatorieae

Eupatorieae

Eupatorieae is a tribe of over 2000 species of plants in the aster family. Most of the species are native to tropical, subtropical, and warm temperate areas of the Americas, but some are found elsewhere...

.



The taxa that belong to Eutrochium are:

• Eutrochium dubium (Willdenow ex Poiret) E. E. Lamont – Coastal Plain Joe-Pye Weed
• Eutrochium fistulosum (Barratt) E. E. Lamont – Hollow Joe-Pye Weed
• Eutrochium maculatum
  Eutrochium maculatum
  Eutrochium maculatum is a member of the Asteraceae family. It ranges from Missouri east to the Atlantic Ocean and as far north as Ontario and Quebec south to Kentucky....
  
  (Linnaeus) E. E. Lamont – Spotted Joe-Pye Weedhttp://plants.bees.net/gallery/view_photo.php?set_albumName=asteraceae&id=Photo_Eupatorium_maculatum_342A_7_30_01_Home
  • Eutrochium maculatum var. bruneri (A. Gray) E. E. Lamont
  • Eutrochium maculatum var. foliosum (Fernald) E. E. Lamont
  • Eutrochium maculatum var. maculatum
• Eutrochium purpureum (Linnaeus) E. E. Lamont – Sweet Joe-Pye Weed, Green-stemmed Joe-Pye Weed, Queen of the Meadow, Gravel Root, Kidney Root, Purple Boneset
  • Eutrochium purpureum var. holzingeri (Rydberg) E. E. Lamont
  • Eutrochium purpureum var. purpureum
• Eutrochium steelei (E. E. Lamont) E. E. Lamont

Medicinal uses

Joe Pye, an Indian healer from New England, used E. purpureum to treat a variety of ailments, which led to the name Joe-Pye weed for these plants.