VASCULAR PLANTS IN A DECIDUOUS SEASONAL FOREST FRAGMENT, EASTERN BOUNDARY OF THE CAATINGA, PARAIBA, BRAZIL

Abstract

Floristic investigations within the Caatinga have received substantial attention in recent decades. Nonetheless, knowledge of the floristic composition within its bordering regions, particularly along the eastern boundary where the Caatinga interlaces with the Atlantic Forest, remains limited. This research aims to analyze the floristic composition of a Deciduous Seasonal Forest fragment situated at the eastern boundary of the Caatinga, Paraíba, Brazil. The data collection process encompassed randomized botanical samplings conducted among January 2021 and February 2023, encompassing all vascular plant species. A total of 204 species, belonging to 168 genera and 68 families, were meticulously cataloged. Fabaceae, Malvaceae, Poaceae, Euphorbiaceae, Asteraceae, Bignoniaceae, and Rubiaceae were the prominent families, constituting 52.4% of the species. Predominant genera included Croton L., Sida L., Mimosa L., Senna Mill., Cyperus L., and Handroanthus Mattos, representing 13.7% of the species recorded. Among the documented taxa, 46 of them are exclusively endemic to Brazil, 14 to the Northeast, 18 to the Caatinga, and 16 were newly documented within Paraíba state. The Asteraceae family garners particular attention among the new records, contributing with six species. Eugenia zigzag (Myrtaceae) stands out for being recently discovered by science and still lacking comprehensive information regarding its geographical distribution.