Wikipedia
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. Well-known members are Stevia rebaudiana (used as a sugar substitute), a number of medicinal plants ( Eupatorium), and a variety of late summer to autumn blooming garden flowers, including Ageratum (flossflower) and Conoclinium (mistflower).
Plants in this tribe have only disc florets (no ray florets) and petals which are white, slightly yellowish off-white, pink, or purple (never a full yellow).
Within the aster family, the Eupatorieae are in the subfamily Asteroideae. Within Asteroideae, they are in the supertribe Helianthodae. Within Helianthodae, they belong to an informal group without taxonomic rank called the phytomelanin cypsela clade, which contains 11 tribes.
The sister tribe of Eupatorieae is probably Perityleae. This result received moderate statistical support (68% bootstrap percentage) in a study published in 2002.