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Effective identification of plant species is fundamental for a better understanding of natural regeneration. However, classical taxonomic methods largely rely on reproductive structures, which are frequently absent in juvenile individuals. To overcome this difficulty, several approaches may be applied, a good example being external anatomy of the leaf epidermis (hereafter micro-morphology). Therefore, the aim of this paper was to test whether the former cited trait can provide suitable distinctive characters for identification of tree species seedlings in general. We chose six common species from the Southern Brazil Seasonal Forest to proceed with our tests, from which we collected two to four leaves of randomly selected seedlings (five replicates/species). We, then, printed leaf epidermis on a microscope slide with instant adhesive and analyzed for diagnostic features. Our analyses showed that several anatomical characteristics of the leaf surface are distinct enough to allow a correct species identification, such as the shape of the anti-clinal walls of epidermal cells, the shape of stomata, and the presence/absence of glands and cuticle. Hence, the conclusion of this study is that leaf epidermal anatomy can be used as a source of diagnostic characteristics to correctly identify the seedlings of forest species. A identificação eficaz de espécies vegetais é fundamental para uma melhor compreensão da regeneração natural. Contudo, métodos taxonômicos clássicos dependem de estruturas reprodutivas, geralmente ausentes em indivíduos jovens. Para superar essa dificuldade, várias abordagens podem ser aplicadas, sendo um bom exemplo a anatomia externa da epiderme foliar (doravante micro-morfologia). Portanto, nosso objetivo foi testar se a micro-morfologia da epiderme foliar pode fornecer caracteres distintivos suficientes para a identificação de plântulas de espécies arbóreas em geral. Escolhemos seis espécies comuns da Floresta Estacional do Sul do Brasil para realizar uma prova de conceito, sendo coletadas de duas a quatro folhas de plântulas selecionadas aleatoriamente (cinco repetições/espécies). Em seguida, a epiderme foliar foi pressionada em uma lâmina de microscopia com adesivo instantâneo, cuja imagem impressa foi analisada em busca de características diagnósticas. As análises mostraram que várias características anatômicas da superfície foliar são suficientemente distintas para permitir uma identificação correta das espécies, como o formato das paredes anti-clinais das células epidérmicas, o formato dos estômatos e a presença/ausência de glândulas e cutícula. Portanto, a conclusão deste estudo é que a micro-morfologia epidérmica foliar pode ser usada como fonte de características diagnósticas para identificar corretamente as plântulas de espécies florestais.

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.

Bamboos are fast-growing plants, with outstanding physical-mechanical characteristics that may be chiefly ascribed to the features and dimensions of their main structural element: their fibers. This study aimed to perform a dimensional description (length, width, lumen diameter and wall thickness) and depict the indices and technical coefficients of fibers of bamboo species that occur in Brazil, through a bibliographical survey. The results showed that the basic density in test stem-specimens of the surveyed species varied between 0.451 g cm-3 and 0.780 g cm-3, what revealed a great variability among them. The average values observed for the fiber dimensions were 2.29 mm for length, 16.4 µm for total width, 6.4 µm for wall thickness and 3.5 µm for lumen diameter. From these data, it was possible to estimate indices and technical coefficients that support good physical-mechanical characteristics of bamboo in the several studied species.

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.

Este trabalho apresenta os resultados do levantamento florístico e estudo taxonômico abrangendo o gênero Collaea na Região Sul do Brasil. Este gênero é exclusivamente sul-americano, possuindo seis ou sete espécies, distribuídas pelo Peru, Bolívia, Brasil, Paraguai e no norte e centro da Argentina. Para a Região Sul foram confi rmadas três espécies: Collaea aschersoniana (Taub.) Burkart, C. speciosa (Loisel.) DC. e C. stenophylla (Hook. et Arn.) Benth. É apresentada uma chave para a identifi cação dos táxons estudados, além de ilustrações, descrições e dados ecológicos. We carried out a fl oristic survey and taxonomic study of the genus Collaea DC. (Leguminosae, Papilionoideae) in South Brazil. This genus occurs exclusively in South America, including six or seven species found in Peru, Bolivia, Brazil, Paraguay, central and northern Argentina. In South Brazil, three species were confi rmed: Collaea aschersoniana (Taub.) Burkart, C. speciosa (Loisel.) DC. and C. stenophylla (Hook. et Arn.) Benth. An identifi cation key, descriptions and illustrations for all taxa are provided, as well as ecological and distribution data.

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.