The asterids are one of the largest subgroups of the flowering plants, with more than 75,000 species. Within the asterids, these species are divided about equally between two large clades (evolutionary lineages), shown in the diagram above.
All the groups to the left side of the cladogram above form a group known as the Lamiidae; the name comes from the Lamiaceae (mint family) which is a member of the group. The Lamiidae also includes the Scrophulariales (figworts and verbenas), Oleaceae (olive family), Gentianales (gentians), Rubiales (coffee group), and the Solanales (potato group).
Those groups to the right side of the cladogram may be called the Asteridae, though that term has sometimes been used to include most of the groups shown above. The name Asteridae comes from the Asteraceae (sunflower family) which is a member of the group. The Asteridae also includes the Campanulaceae (bell-flower family), Dipsacales (teasels and honeysuckles), Apiales (carrot group), and the Aquifoliaceae (holly family).
Several small obscure groups also belong to the asterids, but because they have poor fossil records we have chosen not to include them. However, one such group, the Garryaceae, does have a fossil record. It has usually been classified with the Cornaceae (dogwoods), and you can read about it in that exhibit. Molecular evidence suggests that the Garryaceae may actually be closely related to the Lamiidae, but no formal change in its classification has yet been made.
For more information on current thought in asterid systematics, visit the Tree of Life.
S. Magallón, P. R. Crane, & P. S. Herendeen, 1999. Phylogenetic Pattern, Diversity, and Diversification of Eudicots. Ann. Missouri Bot. Gard. 86(2):297-372.
R. G. Olmstead, B. Bremer, K. M. Scott, & J. D. Palmer, 1993. A parsimony analysis of the Asteridae sensu lato based on rbcL sequences. Ann. Missouri Bot. Gard. 80(3):700-722.