Aim Despite increasing scientific interest in the Indo‐Australian Archipelago (IAA), this geographically complex region, hosting an outstanding level of marine and terrestrial biodiversity, remains only partly understood biogeographically. We present an updated and resolved phylogenetic tree for the woody genus Aglaia, and we investigate the origin and dispersal history of Aglaia. Location Australasia, Indo‐Australian Archipelago, Indomalesia, Pacific islands. Methods Sequence data from the nuclear ribosomal internal transcribed spacers (ITS) were used to reconstruct the phylogenetic relationships of 182 taxa. The phylogeny was then used in combination with fossil data and secondary calibration information to estimate divergence times using a relaxed molecular clock approach. Biogeographical scenarios and potential ancestral areas were investigated using statistical dispersal–vicariance analysis (S‐DIVA) and the dispersal–extinction–cladogenesis (DEC) method. Results Our study showed that the crown group of Aglaia dates back to the Oligocene/Miocene boundary (c. 23.0 Ma), with major divergence events beginning in the middle Miocene (c. 13.8 Ma). Sundaland was confirmed as the area of origin of modern Aglaia. The results further provided evidence that dispersal routes existed between the Sunda Shelf and Wallacea and further east to the Pacific islands, crossing both Wallace's and Lydekker's lines. Main conclusions The directionality of dispersal events to or across Wallacea was predominantly eastwards, following the expansion of wet tropical forest across Wallace's Line and beyond. However, several reversal dispersal events occurred as well. During the Pleistocene (0.1–2.6 Ma) there were long‐distance dispersal events from the western Pacific islands back to Sundaland or the Philippines, which might have been facilitated by birds. In summary, our study confirms that Aglaia had a Sundanian origin and started to disperse eastwards during the Miocene (5.3–23.0 Ma), with limited dispersal across Lydekker's Line. The comparison of the age of clades with the proposed age of their areas of distribution based on independent geological evidence showed good temporal agreement.

Hoya, a species‐rich, mostly epiphytic genus within tribe Marsdenieae (Apocynaceae), occurs in tropical and subtropical forests of the Indo‐Australian Archipelago (IAA). Previous molecular phylogenetic studies based on a restricted taxon sample have provided a first phylogenetic framework for the genus. Questions remain, however, about the evolution and relationships among the over 300 species of the genus. Here, we (1) present the first well‐resolved phylogenetic tree based on sequences of the plastid spacer regions trnH‐psbA, trnT‐trnL, and of the nuclear‐encoded ITS and 5′‐ETS regions, for 154 species covering all proposed sections and (2) we discuss the evolution of epiphytism and its possible role in the successful radiation of Hoya in the tropical forests of the IAA in light of the new phylogenetic results. According to our results, species of Hoya group into six major lineages (Clades I–VI) with widespread geographic distribution. The earliest‐diverging epiphytic lineages of Clade I are restricted to subtropical continental Asia or tropical to subtropical Australasia (Clade IV), whereas their non‐epiphytic relatives are limited to the tropical Indomalayan (Clade II/III) and Australasian (Clade II) parts of the IAA. Clade V (tropical Indomalaya and Australasia) and Clade VI, with outposts in the Himalayas, Japan, and throughout Australasia, represent the second phase of diversification within Hoya. We hypothesise that Hoya is of tropical to subtropical Indo‐Burma/Himalayan origin and that the common trait epiphytism is connected with the onset of monsoon climates during the Himalayan uplift. The subsequent dispersal of Hoya into the many subareas of the IAA region and eventually Australia and the Southwest Pacific, and its success‐ ful radiation there, are proposed to be linked to its epiphytic life style, a trait that is today only found in 10% of angiosperms.