The Pacific Islands are well known for their role in the study of evolution.The source areas of ancestors of their endemic biotas and how they arrived on these isolated land masses is also of great biogeographical interest.The Compositae is the largest family of flowering plants in the world (~25000 spp).It is well represented in Pacific Oceania making it an ideal group to study dispersal and evolution.A database was constructed using herbarium specimens, literature, online sources, published floras, checklists, revisions and monographs to catalogue all known Pacific Compositae.Combining this with recent phylogenetic information we inferred the natural range of each taxon and their area of origin.We found 39-44 lineages native to Pacific Oceania with 176 species in 36 genera for which 174 had sufficient information to determine their origins.Of these,158 species are endemic to either Hawaii or SE Polynesia.Thirteen-14 lineages originated from SE Asia or Asia,14-18 from Australia, New Guinea, New Zealand, and 6-7 from western North America.These source areas are similar to those reported for the Hawaiian flora as a whole, although some, including the Neotropics, do not appear to be sources of Compositae. Per considerable discussion of theoretical ideas on island evolution, Pacific taxa of Compositae comprise several well known cases of adaptive radiation (silverswords, Bidens), often accompanied by movement from coastal to montane habitats.They also exemplify other classic examples of insular evolution.For instance, loss of dispersibility is well documented in Bidens and evolution of woodiness from herbaceous ancestors is documented in Fitchia and Artemisia.Shifts in sexual systems to promote outcrossing and/or self-incompatibility also occur.