Croton buiquensis (Euphorbiaceae), a new species from northeastern Brazil, its phylogenetic placement, and niche modeling
Abstract
A new species of Croton endemic to the municipality of BuĂque in the state of Pernambuco (northeastern Brazil) is here described. Morphological and ITS molecular data provide evidence for placing C. buiquensis sp. nov. as part of Croton section Pedicellati. Specimens of C. buiquensis had been previously identified in herbaria as C. pedicellatus, but the former can be distinguished from the latter by the hispid indumentum of the leaf blade, the oval shape of the petals of staminate flowers, pistillate flowers with 4-fid to multifid styles, and a crossbow-shaped caruncle. Evidence from ecological niche modeling points to other areas in the state of Pernambuco, specifically the "Agreste" region, as likely locations for the occurrence of the new species, which could be the target of future botanical surveys. Croton buiquensis is here provisionally considered as Critically Endangered based on IUCN criteria. This is the first record of multifid styles (more than six stigmatic tips) in C. sect. Pedicellati and also the first species of the section endemic to the state of Pernambuco.