The family Asteraceae or Compositae (known as the aster, daisy, or sunflower family) is the second largest family of flowering plants, in terms of number of species.
The name Asteraceae is derived from the type genus Aster, while Compositae, an older but still valid name, means composite and refers to the characteristic inflorescence, a special type of pseudanthium found in only a few other angiosperm families. The study of this family is known as synantherology.
According to the Royal Botanic Gardens of Kew, the family comprises more than 1,600 genera and 23,000 species. The largest genera are Senecio (1,500 species), Vernonia (1,000 species), Cousinia (600 species) and Centaurea (600 species). The circumscription of the genera is often problematic and some of these have been frequently divided into minor subgroups.
Asteraceae are cosmopolitan, but most common in the temperate regions and tropical mountains.
The largest genera are Senecio (1,500 species) Vernonia (1,000 species) Cousinia (600 species) Centaurea (600 species)