AQUATIC MACROPHYTES: A FLORISTIC INVENTORY ON THE BANKS OF THE TROMBETAS RIVER, ORIXIMINÁ, PARÁ

Resumo

Macrophytes are common in flooded and humid environments and stand out for their diverse life forms. The present study aimed to understand the diversity of macrophytes along the banks of the Trombetas River in Oriximiná, Pará. A floristic inventory of species occurring in an urban cove of the municipality was conducted. Collections took place between February and May 2024 along a 300-meter stretch that is submerged during the high-water period in the Trombetas River. A total of 30 families, 63 genera and 74 species were identified. The most abundant families were Euphorbiaceae, Fabaceae and Asteraceae, with Ludwigia L. (4 spp.) and Phyllanthus L. (4 spp.) being the most diverse genera. A large number of amphibious species were observed, which comprised 69% of the cataloged plants, with 23% being emergent and 8% belonging to other life forms. In the conservation status assessment, 56 species were classified as Data Deficient (DD) and 15 species as Least Concern (LC). Wedelia rudis (Baker) H.Rob. was identified as endemic to Brazil, while the others were non-endemic. The geographic distribution analysis showed that 65 species occur throughout Brazil, five in the Brazilian Amazon: Wedelia rudis, Trichospira verticillata (L.) S.F.Blake, Eclipta prostrata (L.) L., Mimosa dormiens Humb. & Bonpl. ex Willd., and Melochia siphonandra (Turcz.) Dorr; and only Malachra radiata (L.) L. occurs in the Amazon, Caatinga and Atlantic Forest. This research contributes to understanding the aquatic biodiversity of the Amazon region, which remains understudied, and conserving these plants may be an effective strategy for mitigating pollution in aquatic environments.