The present classification of extant flowering plants (Magnoliopsida) updates and revises those presented previously by bringing together the vast majority of new information published since 1999. The extant members of Magnoliopsida are subdivided into 12 subclasses, 35 superorders, 87 orders, 40 suborders, 472 families, and 400 subfamilies. The number of genera and species for each accepted taxon is indicated, along with a statement of the taxonomic confidence that the taxon is worthy of recognition as outlined. Authorships and year of publication are provided for each accepted name and cited synonym. A rule change adopted in 2005 at the Vienna Botanical Congress has fundamentally altered authorships and valid places of publication for hundreds of names, and the full extent of the changes is unknown at present. Newly proposed names include subclass Malvidae; superorder Berberidopsidanae and Huerteanae; suborders Aralidiineae, Asphodelineae, Chloranthineae, Eriocaulineae, Hamamelidineae, Juglandineae, Myricineae, Papaverineae, and Xyridineae; and subfamilies Circaeasteroideae, Dampieroideae, Dasypogonoideae, Davidsonioideae, Ebenoideae, Goetzeoideae, Hesperocallidoideae, Hortonioideae, Isophysidoideae, Kingdonioideae, Laxmannioideae, Ledocarpoideae, Lilaeoideae, Lomandroideae, Morkillioideae, Octoknemoideae, Petunioideae, Phormioideae, Rhynchothecoideae, Sargentodoxoideae, Sclerophylacoideae, Siparunoideae, Sparattanthelioideae, Styloceratoideae, Tribeloideae, Tricyrtidoideae, and Xanthoceroideae.