Lippia (Verbenaceae) do Brasil: atualização taxonômica, biogeografia e conservação

Abstract

Brazil is facing a serious environmental crisis that is endangering all biodiversity and is the main center of richness of the genus Lippia, comprising a high number of endemisms, rare and threatened species. Taxonomic problems involving the very close relationship between Lippia and Lantana are reflected in unreliable analyzes and false conclusions about richness, distribution and risk of extinction with serious consequences for conservation. Thus, the absence of a comprehensive study for the genus in Brazil, represents an aggravating factor that impedes the real dimension of its conservation status. Therefore, as part of the studies for the Flora do Brasil 2020 project, this work sought to analyze the specimens of Lippia and Lantana available in virtual botanical collections (Reflora and speciesLink) in order to correct identification issues to construct a reliable database that was used to update the distribution, conduct biogeographic analyzes (Parsimony Analysis of Endemism and Endemicity) and define the conservation status of endemic species in Brazil. 17,821 specimens were analyzed, 11,040 belonging to Lippia and 6,781 to Lantana, and 3,182 specimens had their identification updated. The exploration resulted in 194 occurrence updates for the states, phytogeographic domains and phytophysiognomies, with 29 taxa having their distribution expanded, while nine had their distribution recircumscribed. The genus Lippia stands out for its chemical variety with great pharmacological potential, comprising 140 species. It is represented in Brazil by 87 species, 63 of which are endemic, characterized by a mostly restricted or micro-endemic distribution, with greater richness and endemicity in the Cerrado and campos rupestres of the Cadeia do Espinhaço, especially in the Serra do Espinhaço Meridional located in Minas Gerais, state responsible for the greater number of threatened species. The evaluation of the conservation status of the species showed that about 97% of the endemic taxa in Brazil were included in some threat category (seven as “Critically Endangered”, 20 as “Endangered” and 36 as “Vulnerable”), even those inserted within UCs, mainly due to agricultural activities, deforestation and fires, revealing that almost half of the genus is threatened. Among the domains, the Cerrado holds the largest number of species included in threat categories (47), being one of the most impacted by deforestation that has been devastating its native vegetation cover. If conservation measures are not targeted, especially for the Cerrado and campos rupestres, several species could be extinct globally.