Showing papers by "Cássio van den Berg published in 2017"

Amazon plant diversity revealed by a taxonomically verified species list

Abstract: 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.

A Molecular Phylogeny and Taxonomic Notes in Caamembeca (Polygalaceae)

Abstract: Caamembeca (Polygalaceae) is a genus of 13 species endemic to South America. The genus is morphologically distinctive, e.g. supported by the putative morphologic synapomorphy of paired glands in a stipular position and on the rachis. However, its monophyly has not been robustly tested as only four species have been included in previous phylogenetic analyses. We present a phylogenetic analysis of 11 species based on nrITS, matK, the trnL intron, and trnL-trnF intergenic spacer. Relationships among Caamembeca species are discussed, and three new combinations are made, Caamembeca amazonensis, Caamembeca autranii, and Caamembeca formosa, providing an improved understanding of the genus.

A new infrageneric classification for Amorimia (Malpighiaceae) based on morphological, phytochemical and molecular evidence

Abstract: Phylogenetic relationships for 14 of the 15 species of Amorimia (Malpighiaceae) were inferred based on ndhF plastid DNA and ETS nuclear ribosomal DNA using both parsimony and Bayesian methods. Our results show that: (1) the monophyly of the genus is corroborated with the new circumscription of the A. rigida complex; (2) several morphological and phytochemical characters support Amorimia and its two main clades; and (3) these clades can be proposed as new subgenera in Amorimia .

Lapidia , a new monotypic genus of Asteraceae (Eupatorieae) from Brazil, and its phylogenetic placement

Abstract: Asteraceae is the family with the highest species number in the rocky fields (campos rupestres) of the Chapada Diamantina, Bahia, Brazil. On the basis of several collections from this area, we are proposing a new genus of Asteraceae based on morphology and phylogeny, to accommodate a species newly described here. Lapidia apicifolia is a loosely ramified shrub 2–4 m high, stem tomentose, leaves opposite-decussate, laminae conduplicate, petiolate, receptacle flat, epaleaceous, glabrous, and pappus of bristles fused at base, irregular in length, fringed and purplish. In a phylogenetic analysis using sequence data from ITS and trnL-trnF of selected members of Eupatorieae, Lapidia is indicated as sister group of a highly supported clade with Morithamnus , Bahianthus and Catolesia . This group is composed by loosely branched shrubs, most with leaves that are lax, stems, leaves and involucral bracts that are viscid ( Bahianthus and Morithamnus ) and, if not, trichomes (tomentose indumentum) are developed ( Lapidia ), to protect against both solar radiation and loss of water. A description, illustrations, and a discussion about related and sympatric genera are presented.