With more than 56,000 species (excluding fungi), Brazil has one of the richest floras in the worldnearly 19% of the world flora. Our knowledge of the diversity and status of nonvascular plants in Brazil is still fragmentary, although localized studies on algae have revealed loss of species resulting from environmental pollution. Emphasis on local floral surveys, rather than wider taxonomic studies, has obscured estimates of national totals for most taxonomic groups. Knowledge of angiosperms, especially monocotyledons (of which 45% of the species are endemic), is more complete than most. For this group figures are more reliable, with some distribution patterns, endemism levels, and centers of diversity identified. Much, however, still awaits discovery. Coordinated efforts to catalog Brazil's flora are in progress and include projects such as the conservation priority-setting workshops of the Brazilian Ministry of the Environment, which have identified key conservation areas in the major biomes; development of threatened species lists for plants; and the assembly of type data on species of northeastern Brazil through the Darwin Initiative-all of which greatly assist in increasing our knowledge. These initiatives also underline the urgent need to expand the numbers and geographic spread of projects on plant systematics and taxonomy in Brazil, a measure that demands adequate provision of funding and training programs for plant specialists. Finally, Brazil's environmental agency (IBAMA) could play a proactive role in opening protected areas under its jurisdiction, thereby facilitating botanical research by university departments and research institutes. Biodiversidad y Conservación de Plantas en BrasilResumen: Con más de 56,00 especies (excluyendo hongos), Brasil tiene una de las floras más ricas del mundo-casi 19% de la flora mundial. Nuestro conocimiento de la diversidad y del estatus de plantas no vasculares aun es muy incompleto, aunque estudios sobre algas han revelado la pérdida de especies debido a la contaminación ambiental. Elénfasis en estudios florísticos locales, en lugar de estudio taxonómicos más amplios, ha enmascarado a las estimaciones de totales nacionales en casi todos los grupos taxonómicos. El conocimiento sobre angiospermas, especialmente monocotiledóneas (de las cuales 45% de las especies son endémicas), es el más completo. Las cifras para este grupo son más confiables, y se han identificado algunos patrones de distribución, niveles de endemismo y centros de diversidad. Sin embargo, falta mucho por descubrir. Están en progreso esfuerzos coordinados para catalogar la flora de Brasil e incluyen proyectos-que contribuyen enormemente al incremento de nuestro conocimiento -como talleres de definición de prioridades organizados por el Ministerio del Ambiente, que ha identificadoáreas clave para la conservación en los principales biomas; desarrollo de listas de especies de plantas amenazadas; y la organización de datos sobre especies tipo del noreste de Brasil por medio de la Iniciativa Darwin. Sin emb...
The genus Alcantarea comprises near 30 species endemic to rocky outcrops from eastern Brazil. Most species are ornamental and several are threatened due to habitat loss and over collection. In this paper we examine the phylogenetics of Alcantarea and its relationship with the Brazilian members of Vriesea, a genus of which Alcantarea has been treated as a subgenus. We discuss the morphological evolution of the stamen position and its implication for pollination and the occurrence of Alcantarea in the Espinhaço mountain range rocky savanna-like habitat vegetation. DNA sequence data derived from two plastid markers (trnK-rps16, trnC-petN) and from a low copy nuclear gene (Floricaula/Leafy) together with 20 nuclear microsatellite loci were the data source to perform analyses and construct phylogenetic and Neighbor Joining trees for the genus. Alcantarea is well supported as monophyletic in both Bayesian and parsimony analyses, but sections of Vriesea, represented by the eastern Brazilian species, appear paraphyletic. Microsatellites delimit geographically isolated species groups. Nevertheless individuals belonging to a single species may appear related to distinct clusters of species, suggesting that hybridization and/or homoplasy and/or incomplete lineage sorting are also influencing the analysis based on such markers and may be the reasons for some unexpected results. Alcantarea brasiliana is hypothesized as putative hybrid between A. imperialis and A. geniculata. Spreading stamens, a morphological floral characteristic assumed to be related to Chiropterophily, apparently evolved multiple times within the genus, and invasion of rocky savanna-like habitat vegetation by Atlantic rainforest ancestors seems to have occurred multiple times as well.
-(Leaf anatomy of Brazilian species of Aechmea subgenus Chevaliera (Gaudich. ex Beer) Baker, BromelioideaeBromeliaceae). The subgenus Chevaliera comprises 21 species most of them occuring in several Brazilian ecosystems. In order to expand the taxonomic knowledge of this subgenus, data on the leaf anatomy of 11 species is presented. Among the characters which were described in this study, the most relevant ones are: stomata position, the thickeness of the substomatic chamber cells, hypodermis, number of layers of the water storage tissue, the shape of the cells that form air channels and the distribution of the fibers in the mesophyll.
Recebido em 30/7/96. Aceito em 23/12/96.
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