Overlooked Diversity in the Atlantic Forest: Four New Species of Myrcia (Myrtaceae) from Rio de Janeiro, Brazil

While studying the Myrcia (Myrtaceae) species from the Brazilian state of Rio de Janeiro, we found specimens displaying unusual combinations of morphological features for the genus. Based on evidence from herbaria and fieldwork, we propose that these specimens belong to four new species, which are described here as M. auriflora, M. brachypoda, M. confertiflora and M. palea. Among them, M. confertiflora is assigned to Myrcia sect. Aulomyrcia, while the other species are assigned to Myrcia sect. Calyptranthes. Two species were collected in Dense Ombrophilous Forests in southern and metropolitan Rio de Janeiro, while the other two occur in lowland seasonal forests in the northeastern region. Morphological descriptions, notes on taxonomy, distribution, habitat and phenology are provided for each species, along with illustrations, preliminary conservation assessments, and a map of occurrence records. Myrcia auriflora is categorized as Data Deficient (DD), M. confertiflora as Critically Endangered (CR) and the remaining species as Endangered (EN).