Austrobaileyales is an order of flowering plants, consisting of about 100 species of woody plants growing as trees, shrubs and lianas. Perhaps the most familiar species is Illicium verum, from which comes the spice star anise. The order belongs to the group of basal angiosperms, the ANA grade, which diverged earlier from the remaining flowering plants, and, as such, it is the extant group after the Amborellales and Nymphaeales, that is sister to all remaining extant angiosperms outside of the ANA grade. The order includes just three families of flowering plants, the Austrobaileyaceae, a monotypic family containing the sole genus, Austrobaileya scandens, a woody liana, the Schisandraceae, a family of trees, shrubs, or lianas containing essential oils, and the Trimeniaceae, essential oil-bearing trees and lianas.
The APG system, of 1998, did not recognize such an order. The APG II system, of 2003, does accept this order and places it among the basal angiosperms, that is: it does not belong to any further clade. APG II uses this circumscription:
Note: "+ ..." = optional seggregrate family, that may be split off from the preceding family. The Cronquist system, of 1981, also placed the plants in families Illiciaceae and Schisandraceae together, but as separate families, united at the rank of order, in the order Illiciales.
^Angiosperm Phylogeny: A Framework for Studies of Genome Evolution, Plant Genome Diversity Volume 2, pp. 1–11, 2013, Springer, Pamela S. Soltis and Douglas E. Soltis
^Botanical Journal of the Linnean Society, 2013, 171, 640–654, Structure of the unusual explosive fruits of the early diverging angiosperm Illicium (Schisandraceae s.l., Austrobaileyales), Mikhail S. Romanov, Alexey v. F. CH. Bobrov, and Peter k. Endress.
^Insights into the dynamics of genome size and chromosome evolution in the early diverging angiosperm lineage Nymphaeales (water lilies), Jaume Pellicer, Laura J Kelly, Carlos Magdalena, Ilia Leitch, 2013, Genome, 10.1139/gen-2013-0039