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Background and Aims Cunoniaceae are woody plants with a distribution that suggests a complex history of Gondwanan vicariance, long-distance dispersal, diversification and extinction. Only four out of ~27 genera in Cunoniaceae are native to South America today, but the discovery of extinct species from Argentine Patagonia is providing new information about the history of this family in South America. Methods We describe fossil flowers collected from early Danian (early Palaeocene, ~64 Mya) deposits of the Salamanca Formation. We compare them with similar flowers from extant and extinct species using published literature and herbarium specimens. We used simultaneous analysis of morphology and available chloroplast DNA sequences (trnL – F , rbcL , matK , trnH – psbA) to determine the probable relationship of these fossils to living Cunoniaceae and the co-occurring fossil species Lacinipetalum spectabilum. Key Results Cunoniantha bicarpellata gen. et sp. nov. is the second species of Cunoniaceae to be recognized among the flowers preserved in the Salamanca Formation. Cunoniantha flowers are pentamerous and complete, the anthers contain in situ pollen, and the gynoecium is bicarpellate and syncarpous with two free styles. Phylogenetic analysis indicates that Cunoniantha belongs to crown-group Cunoniaceae among the core Cunoniaceae clade, although it does not have obvious affinity with any tribe. Lacinipetalum spectabilum , also from the Salamanca Formation, belongs to the Cunoniaceae crown group as well, but close to tribe Schizomerieae. Conclusions Our findings highlight the importance of West Gondwana in the evolution of Cunoniaceae during the early Palaeogene. The co-occurrence of C. bicarpellata and L. spectabilum , belonging to different clades within Cunoniaceae, indicates that the diversification of crown-group Cunoniaceae was under way by 64 Mya. [ABSTRACT FROM AUTHOR]

Azorella is a genus with 26 species of Azorelloideae (Apiaceae) that grow from Costa Rica to the subantartic islands, being distintive and dominant in different environments of the Andean Cordilleras from Venezuela to Patagonia. The species of Azorella that grow in Argentina have been revised taxonomically in a previous study. However, knowledge of the remaining species is fragmentary and uneven. The aim of this paper is to update and standardize the information of the 11 species of Azorella absent in Argentina and present in Bolivia, Chile, Colombia, Ecuador, Peru and/or Venezuela. We provide descriptions for those species and update distributional maps, and we solve nomenclatural and typification problems for 41 names, designating 2 type species, 16 lectotypes and 1 neotype. In addition, we provide 10 new illustrations, and an identification key for all the species of the genus. [ABSTRACT FROM AUTHOR]