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Aim Even though all species of Arachis (wild peanuts) develop pods underground (geocarpy), strongly limiting their dispersal ability, this genus is quite widespread in South America. Thus, our goal was to test potential explanations for how Arachis species may have achieved their current distribution. Location South America. Methods We used a dated phylogeny and 1,052 georeferenced records to run several analyses to select the variables that best explain the variation in range size in Arachis species. We tested a set of models incorporating both abiotic (age, association with rivers, niche parameters) and biotic (life span, vegetative growth, dispersal ability) factors thought to influence geographical distribution in order to select those variables that may best explain the range size of Arachis species. Results We found that no single factor was able to satisfactorily explain the geographical distribution of wild peanuts. Our results showed that Arachis range sizes are influenced by a combination of differential dispersal ability and age, although the effect of time alone was small. We also found that as Arachis species are geocarpic, their dispersal ability is positively influenced by presence of rhizomes, which improves the distances reached by individuals. Main conclusions Our research shows that the range sizes of wild peanuts are mainly constrained by differential dispersal ability and time, and they are improved by the presence of rhizomatous growth. We also advocate that applying a set of candidate hypotheses to explain species range sizes is a much better alternative than previous attempts, in which single or few hypotheses have been tested at a time.

Bambus são monocotiledôneas de rápido crescimento, consideradas como regeneradoras ambientais devido à sua capacidade de ocupar solos degradados, reduzindo o processo erosivo. Além disso, várias de suas espécies são utilizadas como matérias primas ligno-celulósicas para diversos usos. Devido à grande importância deste grupo, esse trabalho teve como objetivo estudar a anatomia de hastes adultas de diferentes espécies de bambu, a fim de melhor caracterizar as diferenças estruturais existentes entre grupos. Foram levantadas em literatura informações sobre a caracterização morfológica e anatomia, com destaque para os padrões de classificação de fibras, células de parênquima, bainha de esclerênquima e canais condutores/vasculares (xilema e floema) de diferentes espécies de bambu. As diferenças anatômicas possibilitaram classificar o material em quatro diferentes grupos, sendo os aspectos mais relevantes a forma do feixe fibrovascular e o teor de fibra.

The objective of this paper is to resolve the taxonomic complex formed by G. neesii, G. martii, their infraspecific taxa, and other similar species, totaling eight names. This group grows from southern Uruguay to northeastern Brazil, and the morphology of individuals gradually changes along this latitudinal gradient, making it possible to identify many morphotypes that have been assigned by previous authors either as species or varieties. We combined ecological and morphometrical approaches to increase the resolution within this complex. We used two techniques of cluster analysis within the ecological data to find the correct number of clusters in the data set. The significant groups found by cluster analysis were then tested a posteriori with a permuted MANOVA to discover congruent morphological groups. Our results showed that from the eight previously hypothesized groups, only two were both ecologically and morphologically significant and could represent separately evolving lineages. The necessary nomenclatural changes as well as a short taxonomic description of the taxa are provided in this paper.

The goal of this work was to test if the macro and micro morphological analysis of the leaf surface could provide vegetative diagnostic characters for some of the most common Lauraceae species in Southern Brazilian Seasonal Forests. The leaf printing technique with universal instantaneous adhesive was used for the epidermical microscopical analysis and external macroscospical analyses of leave were made. Microscopic evaluation revealed the visibility and contours of anticlinal walls of epidermical cell and stomata and shape of guard-cells. Macroscopic evaluation showed the absence or presence of characters such as hairiness, domatia and scents. The results showed that analyzed characters, together with other diagnostic characteristics, could contribute in taxonomic delimitation of some common Lauraceae species in the Southern Brazil.Este trabalho teve por objetivo testar se a análise macro e micro morfológica da superfície foliar poderia prover caracteres diagnósticos vegetativos para algumas das espécies mais comuns de Lauraceae encontradas em Florestas Estacionais do sul do Brasil. Utilizou-se a técnica de impressão foliar com adesivo instantâneo universal para a análise microscópica da epiderme e procederam-se análises externas macroscópicas das folhas. Microscopicamente, foram utilizados a visibilidade e os contornos das paredes anticlinais das células epidérmicas, bem como a visibilidade dos estômatos e o formato de suas células-guarda. Macroscopicamente, verificaram-se a presença ou ausência de caracteres como pilosidade, domácias e odores. Os resultados obtidos no trabalho mostraram que os caracteres analisados, juntamente com outras características diagnósticas, podem contribuir na delimitação taxonômica de algumas espécies da família comuns no sul do Brasil.

A synopsis of the genus Galactia (Leguminosae) in Brazil, including taxonomy, ecology, economic potential, and conservation is presented. A taxonomic key, description of one new species (Galactia cordifolia), new synonyms, illustrations, a brief description of the main diagnostic characters of each species, and notes on distribution, ecology and uses are presented.