Packera is a genus of about 75 species of plants in the daisy family, Asteraceae. Most species are commonly called ragworts or grounsels. Its members were previously included in the genus Senecio, but were moved to a different genus based on chromosome numbers, a variety of morphological characters, and molecular phylogenetic evidence.

Senecioneae is the largest tribe of the Asteraceae, or the sunflower family, comprising over 150 genera and over 3,500 species. Almost one-third of the species in this tribe are placed in the genus Senecio. Its members exhibit probably the widest possible range of form to be found in the entire plant kingdom, and include annuals, minute creeping alpines, herbaceous and evergreen perennials, shrubs, climbers, succulents, trees, and semi-aquatic plants.