Rafael Barbosa Pinto

A new subfamily classification of the leguminosae based on a taxonomically comprehensive phylogeny

The classification of the legume family proposed here addresses the long-known non-monophyly of the traditionally recognised subfamily Caesalpinioideae, by recognising six robustly supported monophyletic subfamilies. This new classification uses as its framework the most comprehensive phylogenetic analyses of legumes to date, based on plastid matK gene sequences, and including near-complete sampling of genera (698 of the currently recognised 765 genera) and ca. 20% (3696) of known species. The matK gene region has been the most widely sequenced across the legumes, and in most legume lineages, this gene region is sufficiently variable to yield well-supported clades. This analysis resolves the same major clades as in other phylogenies of whole plastid and nuclear gene sets (with much sparser taxon sampling). Our analysis improves upon previous studies that have used large phylogenies of the Leguminosae for addressing evolutionary questions, because it maximises generic sampling and provides a phylogenetic tree that is based on a fully curated set of sequences that are vouchered and taxonomically validated. The phylogenetic trees obtained and the underlying data are available to browse and download, facilitating subsequent analyses that require evolutionary trees. Here we propose a new community-endorsed classification of the family that reflects the phylogenetic structure that is consistently resolved and recognises six subfamilies in Leguminosae: a recircumscribed Caesalpinioideae DC., Cercidoideae Legume Phylogeny Working Group (stat. nov.), Detarioideae Burmeist., Dialioideae Legume Phylogeny Working Group (stat. nov.), Duparquetioideae Legume Phylogeny Working Group (stat. nov.), and Papilionoideae DC. The traditionally recognised subfamily Mimosoideae is a distinct clade nested within the recircumscribed Caesalpinioideae and is referred to informally as the mimosoid clade pending a forthcoming formal tribal and/or cladebased classification of the new Caesalpinioideae. We provide a key for subfamily identification, descriptions with diagnostic charactertistics for the subfamilies, figures illustrating their floral and fruit diversity, and lists of genera by subfamily. This new classification of Leguminosae represents a consensus view of the international legume systematics community; it invokes both compromise and practicality of use.

Updates to the taxonomy of Swartzia (Leguminosae) in extra-Amazonian Brazil, with descriptions of five new species and a regional key to the genus

In advance of an updated monographic revision of Swartzia (Leguminosae), we discuss the taxonomy of the genus in extra-Amazonian Brazil and present descriptions of five new species. All of the new species are narrowly distributed in eastern Brazil in threatened Atlantic wet forest and coastal scrub habitats. Four of them—S. alagoensis, S. arenophila, S. revoluta, and S. submontana—belong to the diverse and taxonomically challenging section Acutifoliae, which has undergone extensive evolutionary radiation in the region. The fifth, S. thomasii, is a member of the otherwise Amazonian section Glabriplantae and is only subtly distinct from the Amazonian species S. reticulata. The new species and other recent additions to the genus are incorporated in a key to the species of Swartzia of extra-Amazonian Brazil.ResumoComo parte do estudo de atualização da monografia de Swartzia (Leguminosae), são apresentados dados sobre os táxons do Brasil extra-amazônico com a descrição de cinco espécies novas. Todas as novas espécies propostas neste trabalho apresentam distribuição restrita em habitats ameaçados na floresta atlântica brasileira e vegetação arbustiva costeira. Quatro novos táxons—S. alagoensis, S. arenophila, S. revoluta e S. submontana—pertencem à seção Acutifoliae, um grupo diverso e taxonomicamente complexo que teve alta radiação evolutiva na região. A quinta espécie, S. thomasii, pertence à seção Glabriplantae, um grupo mais comum na amazônia, e é apenas sutilmente distinta de S. reticulata, uma espécie amazônica. Devido ao fato da inclusão destes novos táxons e outras alterações recentes na taxonomia de Swartzia no Brasil extra-amazônico, é apresentada uma chave para distinguir as espécies de Swartzia desta área.

Morphological study of fruits, seeds and embryo in the tropical tribe Dipterygeae (Leguminosae-Papilionoideae)

work analyses and describes fruit, seed and embryo morphology of 12 Dipterygeae species. The fruit is quite distinct among genera, being a legume in Taralea, a drupoid legume in Dipteryx and a cryptosamara in Pterodon. It was observed that the three genera present distinct morphological characteristics in the epicarp, mesocarp and endocarp. These structures are strongly associated with the dispersal syndromes presented by the genera. Embryonic descriptions are provided for the first time in this manuscript for the three genera presented here and the main diagnostic characteristics are: (1) a gradual extent of development of the hypocotyl-radicle axis from Taralea (undeveloped) to Dipteryx (the most developed); (2) the plumules are entire in Taralea and pinnate in Dipteryx and Pterodon; (3) a cleft below the hypocotyl-radicle axis in Taralea, absent in the other genera, because of the strongly cordate base of the cotyledonar leaves; (4) differences in the degree of development of the hypocotyl-radicle axis between D. alata, D. rosea and D. micrantha. Dipterygeae presents a noticeable diversity of fruit, seed and embryo, Taralea being the most distinct of all. The results of this morphological analysis suggest an evolutive path for the diaspores in the clade, based on phylogenetic studies which show Taralea as sister to the clade constituted by Dipteryx and Pterodon.

Evidence for a conserved karyotype in Swartzia (Fabaceae, Papilionoideae): Implications for the taxonomy and evolutionary diversification of a species-rich neotropical tree genus

To assess the taxonomic utility of cytogenetic variation in the species-rich neotropical papilionoid legume genus Swartzia and to ascertain the importance of cytogenetic evolution in the diversification history of the genus, a variety of cytogenetic data—chromosome number, chromosome lengths, relative chromosome length, total chromatin length (TCL), CMA/DAPI and FISH—were collected for 19 taxa of Swartzia and for a single species of the related genus Ateleia. In the sampled species of Swartzia, chromosome counts yielded a diploid number of 2n=2x=26. However, both diploid and tetraploid (2n=4x=52) counts were obtained for S. leptopetala. The species of Swartzia presented small chromosomes (0.25μm to 1.41μm), with gradual length variation, furthermore, each of them had two sites of CMA+/DAPI- and two sites of 45S and 5S rDNA. Cytogenetic data for the morphologically anomalous species S. euxylophora convey its close relationship to other species of Swartzia. Ateleia ovata was found to differ from all of the sampled taxa of Swartzia in diploid chromosome number (2n =28). Taken together, these results constitute preliminary evidence for a strongly conserved karyotype pattern in Swartzia and in combination with previously published data suggest that karyological characters, while useful for characterizing the genus, are of limited taxonomic utility within Swartzia. We conclude that cytogenetic evolution involving changes in chromosome number has not figured prominently in the explosive diversification history of Swartzia.

On the “Cangaço” route: a new species of Hymenaea (Leguminosae) from the Brazilian Caatinga

SummaryA new species of Hymenaea from the Caatinga of northeastern Brazil is described and illustrated. H. cangaceira is morphologically similar to H. martiana and H. longifolia, and its geographical distribution overlaps those of both species; however, it differs in the combination of glabrous, ovate to broadly-elliptic leaflets, a glabrous ovary, and relatively short, cylindrical fruit. The new species is well represented in the herbaria of northeastern Brazil. An identification key is provided to distinguish it from other species of Hymenaea that occur in the Caatinga region.ResumoUma nova espécie de Hymenaea da Caatinga do Nordeste brasileiro é aqui descrita e ilustrada. H. cangaceira é morfologicamente similar às espécies H. martiana e H. longifolia e sua distribuição geográfica está sobrepostas as mesmas; contudo, difere na combinação dos folíolos glabros, ovados a largo-elípticos, ovário glabro e um fruto relativamente pequeno e cilíndrico. Esta nova espécie é bem representada nos herbários do nordeste do Brasil. Uma chave de identificação é fornecida para distinguir a presente espécie das demais que ocorrem na região da Caatinga.