Regina Célia de Oliveira

Weed control via intercropping with Gliricidia. II. corn crop

A grande maioria do algodoeiro cultivado comercialmente no mundo possui fibra branca, porem atualmente existe crescente interesse em diversos paises, inclusive no Brasil, pelo algodao de fibra colorida. O uso de fibras naturalmente coloridas reduz a poluicao quimica, por dispensar o uso de corantes. O objetivo deste trabalho foi avaliar o rendimento de fibras de cultivares de algodoeiro em resposta ao controle de plantas daninhas por meio da consorciacao com a gliricidia (Gliricidia sepium). Os cultivares BRS-Verde (fibras esverdeadas), BRS-Rubi (fibras marrons avermelhadas), BRS-Safira (fibras amarronzadas) e BRS-187 8H (fibras brancas) foram submetidos aos seguintes tratamentos: sem capinas, duas capinas (aos 20 e 40 dias apos o transplantio) e consorciacao do algodoeiro com a gliricidia. Na consorciacao, a gliricidia foi plantada entre as fileiras do algodoeiro, usando-se uma plântula por cova, em covas espacadas por 0,50 m. Doze especies de plantas daninhas ocorreram no experimento, a maioria delas pertencente a familia Poaceae. As plantas daninhas ocorreram com diferentes frequencias, distribuidas desuniformemente na area experimental. Os cultivares nao influenciaram a materia seca das plantas daninhas. A consorciacao com a gliricidia reduziu a materia seca das plantas daninhas, mas nao evitou reducoes nos rendimentos de algodao em fibra e em caroco, que foram maiores nas parcelas que receberam capinas. O cultivar BRS-Safira apresentou o maior rendimento de fibras, porem nao houve diferencas entre cultivares quanto ao rendimento de algodao em caroco.

Paspalum (Poaceae) no Rio Grande do Norte, Brasil

Paspalum L. (Poaceae) has high species richness and economic importance in the Brazilian flora. Given the importance of regional studies to increase taxonomic knowledge of the species and update the flora of Brazils list, this study aims to describe the genus and species of Paspalum from Rio Grande do Norte, as part of a larger Flora of Rio Grande do Norte project. Collections were made in all the phytogeographic regions of Rio Grande do Norte during the last four years, and a survey was done of the herbaria with representative collections of local flora. The conservation status of the species was evaluated according to IUCN regional categories. We recorded 16 species of Paspalum in Rio Grande do Norte. Paspalum carinatum Humb. & Bonpl. ex Flugge, P. gardnerianum Nees and P. pumilum Nees are considered vulnerable in Rio Grande do Norte state, due to man-made pressures on the environment where they occur. However, they are not threatened when evaluated on a global scale. Based on an analysis of populations in the field and under cultivation, we propose to synonymize P. pleostachyum Doll under P. ligulare Nees. Contrary to what is found in the literature, the preference for using the name Paspalum crassum Chase over P. tumidum Kuhlm. is justified. This work includes a key for species identification, morphological descriptions, taxonomic and nomenclatural comments, information on distribution and regional-threat criteria, as well as ecological aspects and illustrations of the species.

List of angiosperm species of the riparian vegetation of the Apodi-Mossoró River, Rio Grande do Norte, Brazil

This article describes the riparian vegetation of a river in the Rio Grande do Norte state for the first time. This is a seasonal river in the semiarid region of the Caatinga biome. The study is based on data from herbarium collections and new expeditions from July 2007 to October 2008. Two hundred and forty seven taxa were recorded and of these, 116 are herbs and three of which are epiphytes, 25 sub-shrubs, 77 shrubs or trees, 26 lianas, one parasite, and two palms. This list of species of riparian vegetation in the river Apodi-Mossoro was compared with only two available lists from rivers in the northeast with similar environmental characteristics and showed a low similarity. This study points to the need for preservation of the species and remnants of riparian vegetation of the river Apodi-Mossoro and to increase efforts in the study of this vegetation type.

The genus Cyperus (Cyperaceae) in Rio Grande do Norte State, Brazil

Cyperus is a Pantropical genus and the second richest in species in Cyperaceae. It encompasses about 550 species worldwide, with about 100 of these occurring in Brazil. Studies on the taxonomy of this genus are scarce and punctual in Brazil. In this study, the occurrence of species was surveyed through 27 collecting expeditions across different regions in the state of Rio Grande do Norte and analyzis of specimens of several herbaria. Twenty four species of Cyperus were identified, including six new occurrences and one new species, here described, but that will be properly published in other work. This study includes a dichotomous key for the identification of the species, as well as illustrations, descriptions, taxonomic comments and geographical distribution.

Aspectos da distribuição e conservação de Paspalum L. (Poaceae) em Pernambuco

Given the high richness and importance of Paspalum for the flora of Pernambuco, this work aims to describe the distribution of species of this genus in the state and contribute to the identification and understanding of the environmental factors that influence the distribution of the species and its conservation. With the DIVA-GIS software, maps were developed of the following parameters: species distribution, overlay of species richness by phytogeographic subdivision and a model to predict the areas with favorable climatic conditions for the establishment of the examined species. The species documented with three or fewer records and/or restricted to one location were classified as rare. Paspalum occurs widely in Pernambuco, but the distribution of most species is limited by increased seasonality in the east-to-west direction. In the region that includes the restinga, mata umida, mata seca and agreste subzones all analyzed species are found. The subzone of the mata umida (moist forest) had the largest number of species, followed by restinga (coastal) and the subzone agreste (transition zone between moist and semi-arid regions). The modeling revealed two regions with optimal environmental conditions for the species. These areas are susceptible to human action. Twelve species were classified as rare, occurring mainly in the more humid regions where an area was identified with optimal conditions for the establishment of populations of many species.

Cyperaceae do rio Apodi-Mossoró, Estado do Rio Grande do Norte, Brasil

The Apodi-Mossoro River, located in the Caatinga biome, has its course characterized by diverse landscape sand humid environments, as well as by many members of the family Cyperaceae. Studies on the flora of Cyperaceae are scarce in northeastern Brazil and nonexistent for Rio Grande do Norte State. Twenty-one botanical expeditions were undertaken in this area during the period from July 2007 to May 2008 on four main points in the municipalities of Felipe Guerra, Governador Dix-Sept Rosado, Luis Gomes, and Mossoro. Seven genera and twenty-five species of Cyperaceae were found in the Apodi-Mossoro River, twenty-one of which are new records for Rio Grande do Norte State.This figure more than doubled the number of species of the family known to occur in this Brazilian State. Botanical descriptions, taxonomic comments, identification keys, and illustrations are provided.

Flora das cangas da Serra dos Carajás, Pará, Brasil: Poaceae

This work presents a taxonomic treatment for the Poaceae in the canga of the Serra dos Carajas, Para state, Brazil. The article was prepared according to the guidelines of the project Flora of the canga of the Serra dos Carajas, based on the study of the specimens from the herbaria BHCB, MG and UB. A total of 87 species belonging to 37 genera were inventoried. Among these, Axonopus carajasensis, Paspalum cangarum, P. carajasense and Sporobolus multiramosus are considered endemic to the canga of the Serra dos Carajas; two new species are to be published soon (one of Paspalum and one of Hildaea); and one species of Trichanthecium is under study to determine its taxonomic identity. Six species are recorded for the first time in Para state. Morphological descriptions, identification keys, illustration of the spikelets, photo plates, detailed geographic distribution and diagnostic comments are provided for all species treated.

Micromorphology of the upper anthecium in Mesosetum Steud. and related genera (Poaceae, Arthropogoninae) and its taxonomic applications

Mesosetum is a Neotropical genus with 25 species, and 21 of them occur in Brazil. Mesosetum forms a clade closely related with Keratochlaena rigidifolia and Tatianyx arnacites. The objective of this work was to establish the taxonomic value of the upper anthecium micromorphology for the group. A total of 96 specimens, representing all Mesosetum species (except M. wrightii), K. rigidifolia and T. arnacites were examined under a scanning electron microscope (SEM). PCA and UPGMA analysis were applied using the micromorphologicalcharacters. Fifithteen useful taxonomic characters were identified. We highlight the following characters to distinguish the Mesosetum species: the presence, type and distribution of papillae on the abaxial surface of the upper lemma; the presence of unicellular macrohairs and bicellular microhairs; presence or absence of silica cells and the structure of the germination lid. The present work shows that the micromorphological characters identified are important taxonomically at the specific level, allowing the species identification in many cases.

Biodiversity in Pristine Wetlands of Central Brazil: a Multi-Taxonomic Approach

This study main goal was to characterize biodiversity in tropical pristine wetlands of two protected areas from central Brazil under a multi-taxonomic approach, with special interest on the distribution and identity of those taxa that most represent these reference conditions. Samplings were conducted during dry and rainy seasons (2009), in nine wetlands. We reported 114 herbaceous macrophytes, 334 algae/cyanobacteria, 45 microcrustaceans and 139 testate amoebae. Macrophytes presented the highest beta diversity compared to the other groups (βw = 3.2), while microcrustaceans showed the lowest one (βw = 1.4). The microorganism diversity associated with the dominating emergent macrophytes (e.g., Poaceae and Cyperaceae) was mainly composed of zygnematophycean algae, branched heterocytous cyanobacteria, along with Chydoridae (Cladocera) and Cyclopoida (Copepoda) microcrustaceans and Lesquereusiidae testate amoebae. Many tropical rare/endemic taxa were reported, e.g., among genera Parallela (green algae), Placocista and Quadrulella (testate amoebae), Celsinotum, Ephemeroporus, Metacyclops and Paracyclops (microcrustaceans); also, the genus Paralimnetis (Laevicaudata) is cited for the first time in Brazil. These findings reinforce these small wetlands as potential biodiversity hotspots and stepping stones for dispersing organisms. Finally, the presence of temporary environments among Cerrado wetlands may contribute as an additional beta diversity driver that deserves more attention in future studies.