摘要Biodiversity is not evenly distributed among related groups, raising questions about the factors con-tributing to such disparities. The sunflower family (Asteraceae, >26,000 species) is among the largest and most diverse plant families, but its species di-versity is concentrated in a few subfamilies, pro-viding an opportunity to study the factors affecting biodiversity. Phylotranscriptomic analyses here of 244 transcriptomes and genomes produced a phy-logeny with strong support for the monophyly of Asteraceae and the monophyly of most subfamilies and tribes. This phylogeny provides a reference for detecting changes in diversification rates and pos-sible factors affecting Asteraceae diversity, which include global climate shifts, whole-genome dupli-cations (WGDs), and morphological evolution. The origin of Asteraceae was estimated at ～83 Mya, with most subfamilies having diverged before the Cretaceous–Paleocene boundary. Phylotran-scriptomic analyses supported the existence of 41 WGDs in Asteraceae. Changes to herbaceousness and capitulescence with multiple flower-like capitula, often with distinct florets and scaly pappus/re-ceptacular bracts, are associated with multiple up-shifts in diversification rate. WGDs might have con-tributed to the survival of early Asteraceae by providing new genetic materials to support mor-phological transitions. The resulting competitive ad-vantage for adapting to different niches would have increased biodiversity in Asteraceae.