MALVACEAE JUSS. NO PARQUE NACIONAL DA CHAPADA DAS MESAS, MARANHÃO, BRASIL

Abstract

The Chapada das Mesas National Park (PNCM), located in the southern mesoregion of Maranhão, constitutes an important Protected Area for the Cerrado formations present in the state. Despite the environmental diversity, the region faces intense anthropogenic pressure, mainly due to the advance of the agricultural frontier, especially soybean monoculture and the conversion of forest areas into pastures for cattle ranching. Several studies developed in the PNCM have addressed the floristic diversity of this conservation unit, with special emphasis on angiosperms. However, regarding the family Malvaceae, there are no records of specific taxonomic studies, with its diversity known only from a single floristic survey. Therefore, the present study aimed to carry out a taxonomic treatment of the Malvaceae species occurring in the PNCM. Sampling was based on field expeditions conducted between 2024 and 2025, each lasting an average of five days, covering different phenological periods and distinct vegetation types. Materials from the herbaria CCAA, CEN, GRAU and SLUI were also analyzed. In total, 152 specimens were examined, resulting in the identification of 33 species, distributed across 18 genera and six subfamilies. The subfamily Malvoideae stood out for its diversity, with 14 species, and the genus Sida was the richest. Regarding growth habit, subshrubs predominated (15 species), followed by trees (7), shrubs (6), and herbs (5). In terms of vegetation types, most species were recorded in anthropized areas (17 species), followed by cerrado sensu stricto (11), rocky cerrado (6), gallery forest and cerradão (5), grassland (2), and vereda (1). Seven species represent new records for the state of Maranhão, with Corchorus orinocensis and Sida pernambucensis being new records for the Brazilian Cerrado. Furthermore, the description of a new species of Triumfetta for the Cerrado is proposed, highlighting the region's high potential for taxonomic discoveries. The information presented in this study expands the floristic lists of Maranhão, enriches knowledge about the Malvaceae family, and highlights the importance of new floristic surveys in Cerrado Conservation Units.