Estudos biossistemáticos em humiria st. hil. no Brasil

Abstract

Species are fundamental in both taxonomic and biological studies, their identification and precise delimitation/ circumscription are essential for understanding processes and relationships in the fields of evolution, ecology, systematics, biogeography and conservation biology. Delimting species in plants is a challenge due to its many reproductive strategies and high phenotypic plasticity, unveiling these limits in a “species complex” has been one of the major objectives of modern taxonomy. In the Amazon, some taxonomic groups represent complex species, among them is Humiria balsamifera (Humiriaceae), which represents a broad infra-specific complex that has 14 varieties and two forms in addition to closely related species. The H. balsamifera complex is widely distributed in the Amazon basin and presents large variation and morphological overlap, mainly observed in the shape and size of leaves, which makes it difficult to establish limits between taxa, thus, the use of different data is essential for robust delimitation (circumscription) of the H balsamifera complex so that one can then clarify evolutionary relationships between taxa. The general objective of the thesis was to delimit species in the Humiria and Humiria balsamifera complex, using an integrative approach with multiple evidences. The results of this thesis are presented in three chapters. The first presents evidence based on quantitative data that Humiria and Humiria balsamifera represent a complex of species and varieties that are difficult to define using only morphological data. The second chapter consists of an integrative approach including molecular, morphological (traditional and geometric) and spectral (FT-NIR) data to assess the circumscription, indicating that the taxa can represent a single widely distributed species. In the third, it is a new cinsccription based on the results obtained in the two previous chapters, where descriptions and photographic plates are presented for the species of Humiria and Humiria balsamifera complex, an identification key is presented and taxonomic considerations for each taxon are performed.