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In this paper we present new synonyms and typifications in Erythroxylum sect. Rhabdophyllum: four taxa are synonymized, three of which at the specific level and one at the infraspecific one, and fourteen lectotypifications are made. [ABSTRACT FROM AUTHOR]

A new species of Ipomoea (Convolvulaceae), endemic to the Caatinga domain of northeastern Brazil, is described and illustrated. Ipomoea bonsai has often been misidentified as I. brasiliana or I. subincana in herbarium collections, probably due to the densely pubescent and brochidodromous leaves of all three species. The new species is a shrub, with unexpectedly robust stems and scandent branches. A diagnosis, with a complete morphological description, illustrations, taxonomic comments, conservation status, distribution map, and photographs are presented. [ABSTRACT FROM AUTHOR]

The relative importance of different community assembly mechanisms varies depending on the environment. According to the stress-dominance hypothesis (SDH), assembly mechanisms range from strong abiotic filtering to competition as the environment becomes more favourable. Most evidence for the SDH comes from studies in gradients of conditions (i.e. abiotic environmental factors that influence the functioning of organisms but are not consumed by them). However, we hypothesized that in resource gradients, competition increases as abiotic filtering becomes stronger. To test our hypothesis, we set up eight plots at different sites along an abiotic severity gradient in the Brazilian semi-arid region (BSAR). In each plot, we identified and measured each woody plant species found, and we recorded 11 functional traits of the main species, dividing the traits into alpha (competition effects) and beta (abiotic filtering effects). We investigated the presence of phylogenetic signal in the traits, the community phylogenetic and phenotypic patterns, and associated the variation in these patterns with the availability of water and soil nutrients. We found phylogenetic signal for most (91%) of the traits analysed. The phylogenetic patterns varied from clustered in stressful sites to random or overdispersed in favourable sites, and we concluded that these phylogenetic patterns were the result of historical processes influencing community assembly in different environments in the BSAR. In general, the phenotypic patterns varied from clustered at the most stressful end to random at less stressful sites. Our results show that in resource gradients, any restriction of the resource (hydric or edaphic) intensifies abiotic filtering and, at the same time, increases the competitive hierarchy among species. On the other hand, stochastic processes seem to have a stronger influence under more favourable abiotic conditions, where abiotic filtering and competition are weaker. Thus, we conclude that the SDH is not supported in resource gradients. [ABSTRACT FROM AUTHOR]

Rocky outcrops surrounded by vegetation in northeastern Brazil form special ecosystems of high species richness and endemism and represent priority areas for biodiversity studies and conservation measures. Floristic surveys of rocky outcrops in the State of Ceará resulted in the identification of a new species of Solanum from the Thomasiifolium clade. Its morphological description, geographic distribution, habitat, ecology, informal conservation status, and environmental suitability models are provided and discussed. [ABSTRACT FROM AUTHOR]

Pseudofrenelopsis and Brachyphyllum are two conifers that were part of the Lower Cretaceous (Aptian) taphoflora of the Crato Formation, Araripe Basin, northeastern Brazil. The former genus includes, so far, P. capillata and indeterminate species, whilst the latter is mainly represented by B. obesum, the most common plant megafossil recovered from that stratigraphic unit. Here, the stem and leaf anatomy of Pseudofrenelopsis sp. and B. obesum specimens is revisited, including the first report of some epidermal and vascular traits for both taxa from the Crato Formation. Along with its paleoecological significance, the new data suggest the presence of more than one Pseudofrenelopsis species in the Aptian taphoflora of the Araripe Basin and further support the taxonomic placement of B. obesum within Araucariaceae. [ABSTRACT FROM AUTHOR]

Among the rich paleobotanical record of the Araripe Basin, the coniferous fossil taxon Brachyphyllum stands out, found in the Crato, Romualdo, and possibly Ipubi formations. In these units, species Brachyphyllum obesum, Brachyphyllum castilhoi , and Brachyphyllum sattlerae are found, the first being the most common. However, there are still many gaps, especially regarding the paleoecology and parataxonomy of this fossil genus. This study aims to make a broad review of the current stage of knowledge of Brachyphyllum from the Araripe Basin, a very representative taxon of the local palaeoflora. We consider data available in the literature and morpho-anatomical analyses of new specimen using Scanning Electron Microscopy. The specimen analyzed in SEM has tracheids and features typical of Araucariaceae, like biseriate and alternating intervascular pits. However, there is variation in the number of pits per cross-field compared to other specimens. This variation may indicate greater diversity of fossil Brachyphyllum in the Araripe Basin. All species of Brachyphyllum from the Araripe Basin have xeromorphic characteristics, which can be adaptive responses to the conditions of aridity and/or salinity in the Crato and Romualdo formations. • This manuscript provides a review of the state of knowledge about Brachyphyllum in the Araripe Basin. • Details of the anatomical structure of an unpublished specimen are presented. • Brings new discussions on taxonomy and paleoecology of Brachyphyllum. [ABSTRACT FROM AUTHOR]