Marcelo Trovó

Molecular phylogeny, morphology and their implications for the taxonomy of Eriocaulaceae

Eriocaulaceae e uma familia pantropical com dez generos e cerca de 1.400 especies, com centro de diversidade no Novo Mundo, especialmente no Brasil. A ultima revisao da familia foi publicada ha mais de 100 anos, e ate recentemente, as relacoes genericas e infra-genericas ainda eram pouco resolvidas. Entretanto, tem havido nos ultimos 30 anos, um grande esforco por parte de pesquisadores brasileiros para preencher as lacunas existentes, utilizando caracteres morfologicos e anatomicos, complementados por dados adicionais de diferentes fontes, como palinologia, quimica, embriologia, genetica de populacoes, citologia e, mais recentemente, estudos de filogenia molecular. Tal conjunto de dados tem levado a uma re-avaliacao do relacionamento filogenetico dentro da familia. Neste trabalho sao apresentados novos dados para as regioes de ITS e trnL-F, analisadas separadamente e em combinacao, usando maxima parcimonia e inferencia Bayesiana. Os dados obtidos confirmam resultados ja publicados, e mostram que muitos caracteres tradicionalmente usados para diferenciacao e circunscricao dos generos dentro da familia sao homoplasicos. Uma nova descricao e chave generica para a familia, utilizando caracteres de varias fontes sao apresentadas, refletindo a taxonomia atual das Eriocaulaceae.

Amazon plant diversity revealed by a taxonomically verified species list

Significance Large floristic datasets that purportedly represent the diversity and composition of the Amazon tree flora are being widely used to draw conclusions about the patterns and evolution of Amazon plant diversity, but these datasets are fundamentally flawed in both their methodology and the resulting content. We have assembled a comprehensive dataset of Amazonian seed plant species from published sources that includes falsifiable data based on voucher specimens identified by taxonomic specialists. This growing list should serve as a basis for addressing the long-standing debate on the number of plant species in the Amazon, as well as for downstream ecological and evolutionary analyses aimed at understanding the origin and function of the exceptional biodiversity of the vast Amazonian forests. Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.

Inflorescences in Eriocaulaceae: taxonomic relevance and practical implications.

BACKGROUND AND AIMS Inflorescences are thought to be of enormous taxonomic relevance; however, at the same time they are regarded as being notoriously difficult. This is partly due to the conflicting needs of floristics and evolutionary botany, but partly also due to the complicated and confusing terminology introduced by W. Troll and his school. METHODS The branching patterns of representatives of the genera Eriocaulon, Syngonanthus and Paepalanthus have been studied in the field and from preserved material by scanning electron microscopy. Branching patterns and formation sequences have been analysed and documented in longitudinal schemes and diagrams. Repetitive units of different levels are detected and related to the body plans of other species of the family. KEY RESULTS The repetition of very few different branching patterns on different levels of complexity may lead to highly complex inflorescences. However, terms are needed only for patterns; levels may be numbered consecutively. While complex inflorescences are often described as additions or aggregations of units, there is some evidence that complex inflorescences are often the result of fractionation of inflorescence meristems. CONCLUSIONS Precise descriptions of inflorescences useful for diagnostics and phylogenetics can be much simpler than they often are today. If complex inflorescences are the result of meristem fractionation, intermediate morphotypes cannot be expected. On the other hand, such intermediate morphotypes should occur if a complex inflorescence is formed following an aggregation pathway. Unless the repetitive patterns shown here are not correlated to complementary gene activities the inflorescences are not fully understood.

Five New and Narrowly Distributed Species of Paepalanthus Section Diphyomene (Eriocaulaceae) from Central Brazil

Abstract Five new species of Paepalanthus section Diphyomene are described and illustrated: P. brevis, P. flexuosus, P. longiciliatus, P. macer, and P. stellatus . Paepalanthus brevis, similar to P. decussus, is easily distinguished by its short reproductive axis, and pilose and mucronate leaves. Paepalanthus flexuosus, morphologically related to P. urbanianus, possesses a distinctive short and tortuous reproductive axis. Paepalanthus longiciliatus, morphologically similar to P. weddellianus, possesses long trichomes on the margins of the reproductive axis bracts, considered a diagnostic feature. Paepalanthus macer shares similarities with P. amoenus, differing by its sulfurous capitula and adpressed reproductive axis bracts. Paepalanthus stellatus also has affinity with P. decussus, but possesses unique, membranaceous, reproductive-axis bracts and a punctual inner-capitulum arrangement of pistillate flowers. Four of the described species are narrowly distributed in the state of Goiás, whereas P. brevis is endemic to Distrito Federal. All are considered critically endangered. Detailed comparisons of these species are presented in tables. Comments on phenology, distribution, habitat and etymology, along with an identification key, are provided.

Actinocephalus koernickeanus, a New Species of Eriocaulaceae from Minas Gerais, Brazil

Abstract We describe and illustrate the new species Actinocephalus koernickeanus Trovó & F. N. Costa (Eriocaulaceae, Paepalanthoideae) from the Espinhaço Range in Minas Gerais, Brazil, and compare it with the morphologically similar species, Paepalanthus actinocephaloides Silveira and P. barbiger Silveira, both from Espinhaço Range.

Nomenclatural and taxonomic changes in Paepalanthus (Eriocaulaceae) from São Paulo and Minas Gerais, Brazil

SummaryThe largest genus of the Eriocaulaceae, Paepalanthus, presents many taxonomic problems. Some of these were identified during studies of Eriocaulaceae from the flora of São Paulo State and Caparaó National Park. Here, we propose changes in nomenclature as a solution to such issues, based on type collections, recent collections and field observations. These changes are in agreement with the taxonomic species concept, and the rules established by the International Code of Botanical Nomenclature. We define six lectotypes: P. gneissicola, P. caparoensis, P. caldensis, P. lundii, P. oerstedianus and P. striatus, and six synonyms: P. gneissicola = P. acantholimon, P. loefgrenianus = P. aequalis, P. multicostatus = P. calvus, P. scopulifer = P. caparoensis, P. neocaldensis = P. flaccidus and P. macrotrichus = P. lundii. We also present comments on morphology, protologue and type collections.

Three New Species of Paepalanthus sect. Diphyomene (Eriocaulaceae) from Minas Gerais, Brazil

Abstract.  Three new species of Paepalanthus Mart. sect. Diphyomene Ruhland (Eriocaulaceae) from Minas Gerais (Brazil) are described and illustrated. Paepalanthus arcuatus Trovó, defined by its curved leaves, is known only from the Serra do Cipó National Park and shares morphological characters with P. decussus Körn. Paepalanthus linearis Trovó, defined by its linear leaves, is known exclusively from Itacambira and resembles P. polycladus Silveira. Paepalanthus sericiscapus Trovó, defined by its sericeous scapes, is known only from the type specimens collected in the Serra da Canastra and resembles P. arcuatus. All the species are known only from their type localities and are assigned a preliminary conservation status of Critically Endangered. Morphological variation, habitat, geographic distribution, and conservation status are noted.

Anatomy of scapes, bracts, and leaves of Paepalanthus sect. Diphyomene (Eriocaulaceae, Poales) and its taxonomic implications

Paepalanthus sect. Diphyomene comprises 18 species with a convoluted taxonomic history. Aiming to correlate anatomical structures with the systematics of this group and its relatives, we studied the anatomy of scapes, reproductive axis bracts, and leaves of 20 Paepalanthus species. Bracts and leaves show differences in epidermal cell thickening; mesophyll width; vascular bundle arrangement; presence or absence of a hypodermis; types of cells in the vascular bundle sheath extensions; margin shape and composition; and presence or absence of aquiferous parenchyma. Scapes differ in contour, rib number, and pith size. Some diagnostic characters found are presence of aquiferous parenchyma and absence of vascular bundle sheath extensions in leaves of P. urbanianus; vascular bundles decreasing in size towards the margin of leaves and bracts, and scapes with a triangular contour in P. flaccidus; scapes with nine ribs in P. acanthophyllus and ten in P. macer. All anatomical features are summarized in tables. These results aid in the identification and characterization of the species of P. sect. Diphyomene. They also support the current section circumscription, reinforcing the relevance of the anatomical characters in order to define natural groups.

Actinocephalus pachyphyllus: re-establishment, redefinition, and a new combination in Eriocaulaceae from Brazil

SummaryWe report the rediscovery of Paepalanthus macrocephalus var. pachyphyllus, an obscure taxon known exclusively from the type specimen. We formally re-establish the species Paepalanthus pachyphyllus and propose its combination within Actinocephalus. The species is redefined and illustrated. Actinocephalus pachyphyllus F. N. Costa, Trovó & Echtern. (Eriocaulaceae, Paepalanthoideae) is distinguished from closely related species by possessing cylindrical to canaliculate linear leaves, covered by long trichomes at the base, with a round to obtuse apex, and short paraclades bearing a single scape. The species is endemic to the Espinhaço Range in Minas Gerais. We compare it with Paepalanthus glareosus (Bong.) Körn. and P. trichopeplus Silveira, the most morphologically similar species. Comments on morphological variation, habitat, geographic distribution, conservation status as well as line drawings, photos, and a distribution map are provided.

Actinocephalus verae (Eriocaulaceae), a new species from the Brazilian Campos Rupestres

We describe and illustrate the new species Actinocephalus verae (Eriocaulaceae: Paepalanthoideae). This species is endemic to the rocky outcrops of the Espinhaço range in Minas Gerais, Brazil. We make comparisons with Actinocephalus ithyphyllus and Actinocephalus ochrocephalus, the morphologically most similar species. The new species’ morphological variation, habitat, geographic distribution, and conservation status are discussed.ResumoDescrevemos e ilustramos a nova espécie Actinocephalus verae (Eriocaulaceae: Paepalanthoideae). Esta espécie é endêmica dos campos rupestres da Cadeia do Espinhaço em Minas Gerais, Brasil. Comparamos esta espécie com Actinocephalus ithyphyllus e Actinocephalus ochrocephalus, as espécies mais similares morfologicamente. Fazemos comentários sobre a variação morfológica, habitat, distribuição geográfica e status de conservação.