Sistemática do gênero Gymnanthes Sw. (Hippomaneae, Euphorbiaceae)

Abstract

Hippomaneae is one of the most diverse and complex tribes of Euphorbioideae subfamily (Euphorbiaceae). Of its 33 genera, about 10 have not yet been reviewed and with problematic boundaries. Among these, stood out Gymnanthes to be considered one of the most difficult taxonomy of genera of the tribe, as a result of intra- and intergeneric limits poorly understood and present several nomenclatural and classification problems. In this sense, this thesis aimed to review the neotropical species of Gymnanthes from the morphological analysis. We examined about 5,000 specimens from 93 herbaria, of which 36 were visited, and specimens collected in the field. The results are presented in the form of four papers. (1) In the study of taxonomic revision, a new constituency for Gymnanthes is hereby established which shall comprise 16 species versus the 45 estimated in previous treatments. Of these, 12 species are found in the Neotropics, two in Africa and two in Asia, with the greatest diversity in Central America (8 spp). 26 are proposed sinonimizações five new combinations lectotipificações and 27, and a neotype. Eight names were excluded from the concept of Gymnanthes and transferred to Actinostemon. (2) In the second manuscript, was performed to lectotipificação of Gymnanthes klotzschiana and the transfer of Actinostemon unciformis for your concept. (3) Based on the analysis of species Actinostemon, gender near Gymnanthes, was described in the third article, the species A. roselii. This is easily recognized by the size of staminate címulas bracts, the globoid leaf buds and in the presence of sepals staminate flowers and pistillate. Finally, (4) the last item brought the mapping of the geographical distribution of Gymnanthes boticario, a well-collected species, but just described. It was observed that Gymnanthes boticario shows a distribution pattern associated with semi-arid environments, more precisely the dry forests. A correlation of their distribution with the theory of Pleistocenic Arc was still drawn. It was found that G. boticario supports the Pleistocene theory by presenting a pattern of disjunct distribution within the field of dry forests. Were also cited the first G. boticario records in Bolivia, Paraguay and the Pantanal hillside forests (Mato Grosso do South). The work also addressed the fact that the new species to be described are not necessarily rare or endemic taxa strictly, as reported in the literature. Although Gymnanthes boticario have been described recently (2010), were found by the year of its publication, 81 fish over 18 herbal over 50 duplicates found in 21 institutions, resulting in a total of 131 herbarium specimens distributed in 25 herbaria six different countries (Germany, Bolivia, Brazil, USA, UK and Switzerland). Soon, G. boticario is a common kind of example and well collected that took a long time to be recognized as a new taxon, showing that the new species remain to be described are not necessarily endemic or remote areas with difficult access.