Anatomia e ontogenia de flores e frutos em espécies de Oenocarpus Mart.(Arecoideae, Arecaceae) de Amazonas, Brasil

Abstract

Among native Amazonian species with significant economic potential, Oenocarpus Mart. species stand out, belonging to the Euterpeae tribe, one of the most economically important within Arecaceae. Oenocarpus literally means "fruit-wine," referring to a popular processed drink made from its fruit pulp, highly valued by traditional communities. Species like bacaba, bacabinha, patauá, and patoá are economically important for fruit production, yet there are limited studies on their structure and life cycle. Structural botany, especially floral structure, is crucial for taxonomic and evolutionary insights due to its complex evolutionary patterns. This study included the four Oenocarpus species found in the state of Amazonas, Brazil: O. bacaba, O. bataua, O. mapora, and O. minor. O. mapora was uniquely collected from an introduced population in a flooded igapó forest. Morphological studies utilized morphometric, geometric morphology, and scanning electron microscopy techniques, while anatomical analyses employed light microscopy and specific histochemical reagents. Due to observed phenotypic similarities, O. mapora was selected to characterize its reproductive apparatus and fruit ontogeny, aiming to establish a predictive pattern for the genus and enhance understanding of Amazonian palms. This work is organized into three chapters, collectively forming a detailed knowledge base on the structural organization of flowers across all studied species, along with the detailed origin and development of the fruit (from pistillate floral bud, post-anthesis ovary to mature fruit) in O. mapora, to set a standard for the genus. The first chapter covers the comparative morphoanatomy of pistillate flowers of Oenocarpus species in Amazonas. The second focuses on the morphological characterization of O. mapora's reproductive apparatus as a model for the genus. The third describes the ontogenetic development from the gynoecium to the mature fruit of O. mapora as a prediction for the genus.