Sistemática do gênero Amasonia L. nom. cons. (Lamiaceae)

Abstract

Amasonia L. (Lamiaceae - Ajugoideae), there is the difficult distinction between its species, which makes it complex, and also because little is known about its relationship with related genera. This study aimed to perform a morphological cladistic analysis of the Amasonia genus, to contribute with understanding of its interspecific relationships, and provide subsidies for the correct identification of its taxa. For the taxonomic study were analyzed voucher specimens and from collections held in the Central West region of Brazil. For the cladistic analysis were selected 42 characters of 13 species, of which eight belong to the Amasonia, three Aegiphila and a representative of the genus Clerodendrum and other of Tetraclea. The morphological matrix was developed through the program Nexus Data Editor, version 5.0 and analyzed by Paup 4.0 by the method of maximal parsimony. Were found three equally parsimonious trees with consistence index (CI) = 0, 6852 and a retention index (RI) = 0,7018. Were recognized eight species in the genus: A. angustifolia, A. arborea, A. calycina, A. campestris, A. hirta, A. lasiocaulis, A. obovata and A. spruceana, mainly dispersed in the savanna formation in Midwest Brazil and in the forests of the Amazon domain. Three synonyms were proposed: Amasonia campestris var. surinamensis Moldenke synonymized to A. campestris; A. hirta var. paraensis Moldenke and A. lasiocaulis var. macrophylla Moldenke synonymized to A. lasiocaulis. Amasonia emerged as a monophyletic genus and it had the clade formed by Tetraclea and Clerodendrum as the closest sister group. Amasonia hirta was pointed as a basal group and sister group to the other species. Aegiphila was shown as paraphyletic, but due to its low sampling in this study, few inferences about the genus could be done.