A new classification system and taxonomic synopsis for Malpighiaceae (Malpighiales, Rosids) based on molecular phylogenetics, morphology, palynology, and chemistry Author de Almeida, Rafael F. 0000-0002-9562-9287 Universidade Estadual de Goiás, Campus Sudoeste, Quirinópolis, Goiás, Brazil & Royal Botanical Gardens, Kew, Richmond, UK Author de Morais, Isa L. 0000-0001-8748-9723 Universidade Estadual de Goiás, Campus Sudoeste, Quirinópolis, Goiás, Brazil Author Alves-Silva, Thais https://orcid.org/0009-0001-0760-6019 Universidade Estadual de Goiás, Campus Sudoeste, Quirinópolis, Goiás, Brazil Author Antonio-Domingues, Higor 0000-0001-9405-1930 Royal Botanical Gardens, Kew, Richmond, UK Author Pellegrini, Marco O. O. 0000-0002-8783-1362 Royal Botanical Gardens, Kew, Richmond, UK text PhytoKeys 2024 2024-05-22 242 69 138 journal article 10.3897/phytokeys.242.117469 1.2. 3. Diacidia Griseb. in Martius, Fl. Bras. 12 (1): 119. 1858 . = Sipapoa Maguire , Mem. New York Bot. Gard. 8: 124. 1953 . ≡ Diacidia subg. Sipapoa (Maguire) W. R. Anderson , Mem. New York Bot. Gard. 32: 63. 1981 . Type species: Sipapoa kunhardtii Maguire [≡ Diacidia kunhardtii (Maguire) W. R. Anderson ]. Type species. Diacidia galphimioides Griseb. Notes. Diacidia currently comprises 11 accepted species (seven threatened species; Suppl. material 1 ) of trees, shrubs or subshrubs endemic to campos rupestres and tepuis within the Amazon rainforest biome of South America ( Almeida et al. 2020 ; POWO 2024 ). For an identification key for all species of Diacidia , see Anderson (1981) for the Guyana Highland and Almeida et al. (2020) for Brazil .