The Lactucinae or Lactuca alliance include approximately 200 species distributed across the Northern Hemisphere and Africa. They were not recognised as a separate lineage until the late 20th century and their circumscription is still not fully settled. The generic classification of no other group of the Cichorieae has faced as many controversies as the Lactuca alliance and competing taxonomies coexist. This paper provides the first molecular phylogeny of the subtribe on a global scale as a major step towards its revised systematics. The sampling includes almost 60% of the species-level diversity and spans all species groups. Two datasets were created, one including the nrDNA ITS region, the other five concatenated non-coding plastid DNA loci. Maximum parsimony, maximum likelihood and Bayesian inference were used to produce a robust phylogenetic backbone. The diversification and expansion of the Lactucinae in a geohistorical context was reconstructed by estimating the age of their lineages using relaxed molecular clock dating and by inferring the ancestral areas using Bayesian binary analysis. The redelimited monophyletic Lactucinae are composed of seven lineages that also include Prenanthes, which is confirmed to have a single species, P. purpurea. The positions of two further lineages shift between Lactucinae and Crepidinae in the nuclear and plastid DNA phylogenies. Incongruence between the phylogenies suggests events of ancient reticulation or incomplete lineage sorting in the formation of these latter two lineages and in two of the seven other Lactucinae lineages. The phylogenetic results show a dilemma for Lactucinae systematics: most generic concepts proposed to date are highly artificial but the resolved phylogenetic lineages do not constitute practicable taxonomic entities with our current knowledge. Diversification of the subtribe is inferred to have taken place since the Middle Miocene. Biogeographic analysis proposes that the clade originated in the mountains of the landmass mediating between the European and Asian continents and delimited in the south by the Tethys Sea and in the north by the Paratethys Sea. Several independent migrations have occurred into various parts of Asia, Europe, tropical Africa and North America.

Soroseris, Stebbinsia, and Syncalathium are three genera of the sunflower family (Asteraceae) with restricted distributions on high screes of the Tibetan Plateau. We present a molecular analysis to test the monophyly of the genera, evaluate the phylogenetic relationships and construct their biogeographic diversification history. Nuclear ITS and plastid trnL‐F and psbA‐trnH fragments were analyzed with parsimony, Bayesian inference, and relaxed Bayesian dating for all species of Soroseris, Stebbinsia, and Syncalathium. Stebbinsia is part of a polytomy with several lineages of Soroseris. Syncalathium is biphyletic with Syn. souliei placed within subtribe Lactucinae and the remaining species close to the Soroseris‐Stebbinsia clade within subtribe Crepidinae. Bayesian dating based on ITS sequences and using four fossil calibrations suggests that the stem and crown ages of the Soroseris‐Stebbinsia clade and the two groups of Syncalathium are between 8.44 and 1.56 million years. Stebbinsia should be treated as a section of Soroseris and Syncalathium souliei should be excluded from Syncalathium and either placed in Lactuca s.l. or established as a new genus in Lactucinae. The remaining species are to be treated as Syncalathium s.str. in Crepidinae. The diversification of these groups in the Tibetan Plateau is of relatively young age, and can be explained by rapid diversification and radiation of the Soroseris‐Stebbinsia clade, allopatric speciation within Syncalathium s.str. and convergent evolution of Syncalathium s.str. and Syn. souliei. The speciation events correlated with climatic change and fragmentation of scree habitats during the uplift of the Tibetan Plateau. Possible migration routes in Syncalathium s.str. from the northeast to the central and southern part of the Tibetan Plateau are suggested.