Phylogeny and classification of the Australasian and Indomalayan mimosoid legumes and (Leguminosae, subfamily Caesalpinioideae, mimosoid clade).

The morphologically variable genus is the second largest mimosoid legume genus from the Indomalayan-Australasian region, yet it has not been well represented in phylogenetic studies. Phylogenies that have included multiple representatives of suggest it may not be monophyletic, and the same applies to , another understudied genus of the Archidendron clade. The most comprehensive phylogeny of and to date is presented, based on four nuclear markers (ITS, ETS, SHMT and RBPCO). Exemplars from all genera of the wider Archidendron clade are sampled, including representatives of all series within and the two subgenera of . Our results confirm that and are not monophyletic. Within , only one series (ser. Ptenopae) is resolved as monophyletic and species of are divided into two primarily geographic lineages. One clade is distributed in western Malesia and mainland Asia and includes most representatives of series , while the other is mostly restricted to eastern Malesia and Australia and includes representatives of the seven other series plus two samples of series . No taxonomic changes are made for due to the high level of topological uncertainty and the lack of discrete macromorphological characters separating these two lineages. Each of the two subgenera of is monophyletic but they are not closely related. A new genus endemic to Queensland (Australia), Gill.K. Br. & Bayly, , is described for the former Archidendropsissubg.Basaltica, and combinations for its three species are proposed: (F. Muell.) Gill.K. Br. & Bayly, , (F. Muell.) Gill.K. Br. & Bayly, , and (C.T. White & W.D. Francis) Gill.K. Br. & Bayly,