Contribuições para o conhecimento da taxonomia da família Apocynaceae no Estado do Pará.

Abstract

Apocynaceae Juss. belongs to the order Gentianales, presents approximately 355 genera and is estimated to comprise between 3,700 and 5,000 species, occurring in all continents except Antarctica. In Brazil, the family appear in the top ten list for the country, with 77 genera and 767 species found throughout all biomes, with the Atlantic Rainforest (36,5%), Amazon Rainforest (30,5%) and Cerrado (29,4%) very well represented. Apocynaceae is currently divided into 5 subfamilies: Rauvolfioideae Kostel., Apocynoideae Burnett., Asclepiadoideae R.Br. ex Burnett., Periplocoideae R.Br., and Secamonoideae Endel. Apocynaceae phylogenetics studies show that, while Asclepiadoideae, Periplocoideae and Secamonoideae are monophyletic, Rauvolfioideae and Apocynoideae are paraphyletic. Taxonomic knowledge of Apocynaceae for the Amazon region is still scarce and incomplete, with only five studies reported: a guide from Reserva Ducke, in the metropolitan region of Manaus, AM, two floristic studies in Marajó Island, PA, a study in the restinga of the state of Pará and the most recent one carried out in the Flora das cangas da Serra dos Carajás, PA. In this context, we propose a taxonomic treatment of Apocynaceae species occurring in the Parque Estadual do Utinga and at the Floresta Nacional de Caxiuanã, aiming at enriching the Amazonian herbarium collections, accurately identifying all available material and possibly describing new species, and / or detect nomenclatural novelties and new occurrences in the region. It is also intended, through this research, to deepen the understanding about the distribution of genera and species present in these two conservation units, besides contributing to the update of Apocynaceae deposited in the collections of the analysed herbariuns and of the Flora of Brazil 2020 on line.