Bignoniaceae nas serras centrais do planalto do Alto Rio Grande, sul de Minas Gerais

Abstract

Bignoniaceae is a Pantropical family composed of eight tribes and two clades. Its representatives are trees, shrubs, or lianas with opposite compound leaves. South America is considered the center of diversity, and in Brazil, there are 34 genera and 420 species, occurring in all phytogeographical domains. The Planalto do Alto Rio Grande extends from the southern end of Minas Gerais, bordering the Planalto do Itatiaia, to the region of São João del Rey and Barbacena. In the center of this region, a group of mountain ranges forming the letter "Z", and in recent years, its flora has been studied, leading to new records and species discoveries. Bignoniaceae has not yet been studied in this area, which is characterized by transitional zones between the Cerrado and the Atlantic Forest. After collecting specimens and reviewing available collections, the family's flora was examined for the mountain ranges and surrounding areas of the municipalities: Carrancas, Ingaí, Itumirim, Itutinga, Lavras, and Minduri. The species list consists of 52 species distributed in the tribes Bignonieae (28 spp.), Jacarandeae (seven spp.), Tecomeae (four spp.), and in the clades Tabebuia Alliance (12 spp.) and Paleotropical (one spp.), totaling 22 genera. Identification keys are provided to determine tribes and genera and descriptions, along with descriptions of the seven species of Jacaranda. Among the species, 28.85% are endemic to Brazil, with Anemopaegma arvense (Vell.) Stelleld ex de Souza ("catuaba") classified as "Endangered", and Handroanthus impetiginosus (Mart. ex DC.) Mattos and Zeyheria tuberculosa (Vell.) Bureau ex Verl. ("buxo de boi") as "Near Threatened". The presence of these species in the region underscores the need for initiatives aimed at conserving native areas in these mountain ranges, which have a high diversity of habitats and vegetation formations but few protected areas or/and conservation units, and intense agropastoral and industrial activities.