Revisão taxonômica de Eugenia sect. Speciosae (Myrtaceae) no Brasil

Abstract

The family Myrtaceae is one of the most representative groups of the Brazilian flora, both in terms of diversity and ecological importance. Within this family, the genus Eugenia stands out for comprising a large number of species, many of them endemic, and for presenting high taxonomic complexity. The section Eugenia sect. Speciosae exemplifies this challenge, as its species share very similar morphological characteristics, which hampers their delimitation, especially when identification is based solely on vegetative material, a common situation in herbarium collections. In this context, this study aimed to update the taxonomy of Eugenia sect. Speciosae in Brazil by compiling standardized morphological information, updated nomenclatural data, and the geographic distribution of the recognized species. The study was based on the morphological analysis of herbarium specimens, including type materials, from different national and international herbaria, accessed mainly through digital platforms such as SpeciesLink, Reflora, INCT Herbário Virtual, and Flora e Funga do Brasil. Approximately 36 specimens were analyzed. Leaf characters were described following the criteria of the Manual of Leaf Architecture, allowing greater terminological standardization and more consistent comparisons among species. Whenever available, floral and reproductive characters were also evaluated, including hypanthium indumentum, sepal morphology, and fruit characteristics, in addition to direct comparisons with original descriptions from the literature. As a result, ten species of Eugenia sect. Speciosae were recognized in Brazil. An updated taxonomic synopsis was prepared, including synonymy, typification, diagnostic notes, geographic distribution, habitat, and conservation status, as well as a complete and updated dichotomous identification key. The analysis of geographic distribution revealed distinct patterns within the section, ranging from widely distributed species to taxa with extremely restricted occurrences. The results highlight the importance of taxonomic revisions based on standardized morphological descriptions and access to digital herbarium collections, contributing to more accurate species identification and providing relevant support for floristic, systematic, and conservation studies.