Sistemática de Paepalanthoideae (Euriocaulaceae): Filogenia, morfologia e taxonomia de Diphyomene (Ruhland) Trovó / Systematics of Paepalanthoideae (Eriocaulaceae): Phylogeny, morphology, and taxonomy of Diphyomene (Ruhland) Trovó

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

This thesis consists of a phylogenetic study involving Paepalanthoideae, and a morphological, nomenclatural, and taxonomic survey of Paepalanthus sect. Diphyomene. Chapter I is a phylogenetic study of Paepalanthoideae based on morphological and molecular data (nrITS and trnL-trnL). The monophyly of Rondonanthus, as a sister group of the remaining Paepalanthoideae, is confirmed, as is the monophyly of Leiothrix and Actinocephalus. Syngonanthus emerges paraphyletic with the current acceptance of Philodice, whereas Paepalanthus and Blastocaulon emerge polyphyletic. However, many infra-generic categories of Paepalanthus emerge as monophyletic groups. The proposal of new genera, as well as complementary phylogenetic studies, is required to achieve a natural classification of Paepalanthoideae. In chapter II, we describe the inflorescence and reproductive axis of Paepalanthus sect. Diphyomene, when using typology and anatomy. Two patterns were found. In P. erectifolius, P. giganteus and P. polycladus the structure is a tribotryum, with a terminal dibotryum, and pherophylls bearing lateral dibotrya. In P. flaccidus, the inflorescence is a pleiobotryum, with a terminal subunit, and without pherophylls. These results confirm that the group consists of two independent lineages, and that the pattern described for the first three species is unique within the family. Chapter III consists of a proposal of generic status for species of Paepalanthus sect. Diphyomene, which emerge monophyletic in chapter I, and possess a unique inflorescence structure as described in chapter II. We propose 10 new combinations, 18 new synonyms, six lectotypifications, two new stati, one neotypification, and one epitypification. In chapter IV we present the taxonomic revision of Diphyomene, a genus with 18 species distributed throughout South America, mostly in the Brazilian Cerrado. The revision consists of a detailed description and comments on the genus, besides an identification key. Descriptions, illustrations, distribution maps and comments on each species are also given. Eight new Brazilian species of Diphyomene are described in appendix 1 and 2.

ASSUNTO(S)

1. paepalanthoideae 6. diphyomene 4. filogenia 4. phylogeny 2. eriocaulaceae 5. morphology 1. paepalanthoideae 3. sistemática 6. diphyomene 2. eriocaulaceae 3. systematics 5. morfologia

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