Taxonomic novelties in Adenocalymma (Bignonieae, Bignoniaceae) endemic to the Atlantic Forest

Background and aims – During ongoing morphological studies of Adenocalymma , we realized that nomenclatural updates are necessary in the genus. Here, we propose a new circumscription of A. acutissimum and the description of the new species A. darwinii . Material and methods – Morphological and phylogenetic evidence support the new circumscription of A. acutissimum , while the new species is recognized based on morphological grounds and compared to A hirtum and A. salmoneum . Key results – We removed the taxa A. comosum , A. comosum var. lanceolatum, and A. nitidum as synonyms of A. acutissimum . We also presented a detailed description for A. darwinii sp. nov., an illustration, and information on its distribution, habitat, phenology, and extinction risk. A map showing the occurrence of both A. comosum and A. darwinii sp. nov. is shown. Conclusion – These results emphasize once again the importance of taxonomic studies in the Brazilian Atlantic Forest and highlight conservation concerns for its flora.