Subfamily Paepalanthoideae encompass the largest generic diversity in Eriocaulaceae. In the present study, the main goals were to infer the phylogeny of this subfamily focusing on Paepalanthus, to evaluate recent classifications and morphological characters in a phylogenetic context and to reconstruct the historical biogeography of the group. Sampling involved 94 ingroup species corresponding to all recognized genera and three outgroup species. Two molecular data sets, nuclear ribosomal internal transcribed spacer (nrITS) and plastid trnL‐trnF, were analysed under parsimony and Bayesian methods. Rondonanthus is monophyletic and confirmed as sister to the remaining Paepalanthoideae. Leiothrix and Actinocephalus are each monophyletic, whereas Syngonanthus may be either monophyletic or paraphyletic with the recognition of Philodice. Four subgenera of Paepalanthus are monophyletic, but P. subgenus Paepalanthus is polyphyletic. Morphological characters used in previous classifications are assessed as putative synapomorphies for recognized genera. Some of the characters employed in defining Paepalanthus subcategories appear to have evolved multiple times, and many clades may be exclusively defined by molecular synapomorphies. Biogeographical reconstructions suggest that the current distribution patterns may be related to vicariance and a few long‐distance dispersal events. Furthermore, some clades are restricted to narrow geographical areas, perhaps important as a means of conserving evolutionary processes. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ●●, ●●–●●.

The pantropical family Eriocaulaceae includes ten genera and c. 1,400 species, with diversity concentrated in the New World. The last complete revision of the family was published more than 100 years ago, and until recently the generic and infrageneric relationships were poorly resolved. However, a multi-disciplinary approach over the last 30 years, using morphological and anatomical characters, has been supplemented with additional data from palynology, chemistry, embryology, population genetics, cytology and, more recently, molecular phylogenetic studies. This led to a reassessment of phylogenetic relationships within the family. In this paper we present new data for the ITS and trnL-F regions, analysed separately and in combination, using maximum parsimony and Bayesian inference. The data confirm previous results, and show that many characters traditionally used for differentiating and circumscribing the genera within the family are homoplasious. A new generic key with characters from various sources and reflecting the current taxonomic changes is presented. Key words: anatomy, ITS, phylogenetics, pollen, trnL-trnF. ResumoEriocaulaceae é uma família pantropical com dez gêneros e cerca de 1.400 espécies, com centro de diversidade no Novo Mundo, especialmente no Brasil. A última revisão da família foi publicada há mais de 100 anos, e até recentemente, as relações genéricas e infra-genéricas ainda eram pouco resolvidas. Entretanto, tem havido nos últimos 30 anos, um grande esforço por parte de pesquisadores brasileiros para preencher as lacunas existentes, utilizando caracteres morfológicos e anatômicos, complementados por dados adicionais de diferentes fontes, como palinologia, química, embriologia, genética de populações, citologia e, mais recentemente, estudos de filogenia molecular. Tal conjunto de dados tem levado a uma re-avaliação do relacionamento filogenético dentro da familia. Neste trabalho são apresentados novos dados para as regiões de ITS e trnL-F, analisadas separadamente e em combinação, usando máxima parcimônia e inferência Bayesiana. Os dados obtidos confirmam resultados já publicados, e mostram que muitos caracteres tradicionalmente usados para diferenciação e circunscrição dos gêneros dentro da família são homoplásicos. Uma nova descrição e chave genérica para a família, utilizando caracteres de várias fontes são apresentadas, refletindo a taxonomia atual das Eriocaulaceae.

The Eriocaulaceae are easily recognized because of the small unisexual flowers in long-pedunculate heads and spiraperturate pollen grains. Their monophyly has never been disputed but internal relationships within the family have not been broadly explored and genera are typically distinguished by few floral characters. Here, we present the first comprehensive phylogenetic study of Eriocaulaceae based on individual and combined molecular datasets, including the plastid psbA-trnH and trnL-F and the nuclear ITS. Results are largely congruent among DNA regions and support the internal dichotomy between the two subfamilies: Eriocauloideae and Paepalanthoideae. Eriocaulon and Leiothrix are strongly supported as monophyletic, whereas Paepalanthus, Blastocaulon, and Syngonanthus are not monophyletic. The phylogenetic nature of Actinocephalus is not resolved and Lachnocaulon, Mesanthemum, Philodice, Rondonanthus, and Tonina (monospecific) are represented in our analyses by a single species each. Based on our results, we suggest two principal generic realignments in the family. The first is the division of Syngonanthus in two genera: Syngonanthus s.str., including Philodice (conserving the former name against the latter), and Comanthera, which is being reinstated to include two sections segregated from Syngonanthus: S. sect. Eulepis and S. sect. Thysanocephalus. The second realignment suggested is the amalgamation of Actinocephalus, Blastocaulon, Lachnocaulon, and Tonina into Paepalanthus s.l. Three 'stat. nov.' within Paepalanthus are published (P. ser. Leptocephali, P. ser. Rosulati, and P. ser. Dimeri).

Previous morphological and molecular studies indicate that Syngonanthus is polyphyletic. Syngonanthus sect. Syngonanthus and S. sect. Carphocephalus as well as Philodice cluster in a monophyletic clade and are included in Syngonanthus. Syngonanthus sect. Eulepis and S. sect. Thysanocephalus are also a monophyletic group that can be used to reestablish Comanthera with a new circumscription and two subgenera: Comanthera subg. Comanthera and C. subg. Thysanocephalus. Characterization of Comanthera and the necessary nomenclatural combinations are provided in this paper. The genus will now include 38 species, six varieties and four subspecies. Of the species, 34 are endemic to Brazil, occurring especially in the Espinhaço Range in Minas Gerais and Bahia. Three species extend from Brazil into other countries of northern South America and one is found only in Venezuela and Guyana. In this paper we also propose 43 new synonyms, 39 new combinations, one name change, three changes of status, eight lectotypifications and one neotypification.