Showing papers in "Acta Botanica Brasilica in 1996"
TL;DR: In this article, the authors tested metodos de coloracao baseados em Roeser (1972) modificado e Kropp (1972), visando a substituicao do corante azul de astra by azul of alciao 8GS or 8GX.
Abstract: foram testados metodos de coloracao baseados em Roeser (1972) modificado e Kropp (1972), visando a substituicao do corante azul de astra por azul de alciao 8GS ou 8GX. As amostras foram fixadas em FAA, desidratadas em serie butilica terciaria e incluidas em parafina. Os cortes histologicos transversais foram corados segundo diferentes baterias de coloracao, modificadas quanto ao tipo de corante usado, diferenciador e serie de desidratacao. As lâminas permanentes foram preparadas com balsamo-do-canada sintetico. Os resultados obtidos evidenciaram que o metodo de Roeser (1972) modificado e melhor que o de Kropp (1972), nas condicoes deste experimento. O azul de astra pode ser substituido por azul de alciao 8GX e a desidratacao pode ser em serie isopropilica ou etilica, sem grande diferenca entre elas. Sao discutidos os resultados provenientes das di ferentes coloracoes. Palavras-chave: metodo de coloracao, azul de astra. azul de alciao, fucsina basica, safranina, histologia vegetal ABSTRACT - (Staining methods of modified Roeser (1972) and Kropp (1972), aiming at substituing the astra blue by aleian blue 8GS or 8GX). Staining methods based on modified Roeser (1972) as well as that of Kropp (l972) were done with leaves of
176 citations
TL;DR: The 53 species of Miconia occuring in the Brazilian State of Sao Paulo probably represent all taxa of the genus collected in this State.
Abstract: The present paper deals with the species of Miconia occuring in the Brazilian State of Sao Paulo. The 53 species listed and described here probably represent all taxa of the genus collected in this State.
61 citations
TL;DR: "Sempre-vivas" is the name given in Brazil to parts of plants, usually scapes and inflorescences, that conserve the appearance of the living structures even after dryed out (everlasting).
Abstract: "Sempre-vivas" is the name given in Brazil to parts of plants, usually scapes and inflorescences, that conserve the appearance of the living structures even after dryed out (everlasting). They are sold locally and exported for interior decoration. In a smaller scale, leaves, fruits and seeds are also used. "Sempre-vivas" species are gathered in the savanna-like formations ("cerrados") of the Central-West and Southeast regions of Brazil, while species of greater commercial value originate from the grasslands with rocky outcrops ("campos rupestres") from the States of Minas Gerais, Bahia and Goias. Species of Eriocaulaceae, Poaceae (Gramineae), Xyridaceae, Cyperaceae and Rapateaceae predominate in a decreasing order. The largest commercial center for this material is the city of Diamantina, in the State of Minas Gerais, where 25 species of Eriocaulaceae, 12 of Poaceae, 9 of Xyridaceae, 2 of Cyperaceae and 1 of Rapateaceae are commercialized. Identification keys for the genera based on characters found in the commercialized parts, brief descriptions, illustrations, list of the analysed material, popular names and comments on the species are presented.
61 citations
TL;DR: O presente estudo objetivou avaliar modificacoes ocorridas na vegetacao em uma area de campo natural, apos oito anos sem influencia de pastoreio, para evidenciating a relacao entre a forma biologica das especies predominantes e os estados pastejado ou excluido.
Abstract: O presente estudo objetivou avaliar modificacoes ocorridas na vegetacao em uma area de campo natural, apos oito anos sem influencia de pastoreio. A area situa-se na Estacao Experimental Agronomica da UFRGS, no municipio de Eldorado do Sul, RS, onde foram realizadas amostragens em 1984 e 1992. Dezesseis unidades amostrais permanentes de 0,25 m2 foram utilizadas para verificar a presenca e o valor de cobertura das especies, pela escala de Daubenmire. Sao apresentados os valores de frequencia e cobertura absolutas (FA e CA, respectivamente) das especies de Gramineae, Compositae, Rubiaceae, Leguminosae, Umbelliferae e Cyperaceae nos levantamentos de 1984 e 1992. O trabalho evidenciou a relacao entre a forma biologica das especies predominantes e os estados pastejado ou excluido. Em Gramineae, especies rasteiras, estoloniferas ou rizomatosas (Paspalum notatum, Axonopus affinis e outras), caracteristicas da area pastejada, foram substituidas por plantas de habito cespitoso (Andropogon lateralis, Elyonurus candidus e outras), capazes de sombrear e sobrepujar as de baixo porte. Especies de compostas e rubiaceas, de um modo geral, apresentaram uma reducao em FA e pouca alteracao em CA. As leguminosas apresentaram principalmente um aumento em FA, mantendo a CA praticamente constante. As umbeliferas destacaram-se pelo aumento da CA em metade de suas especies. Ocorreu o surgimento de 25 e o desaparecimento de 42 especies em 1992.
51 citations
TL;DR: In this article, the seeds of S. elegans and S. niveus were germinated in a growth chamber under controled conditions and in the laboratory under light and dark conditions.
Abstract: The species S. elegans (Bong.) Ruhl. and S. niveus (Kunth.) Ruhl. (Eriocaulaceae) are known in Brazil as star flowers and they grow in the rupestrian fields of Serra do Cipo - MG. They are used for ornamental purposes so data on their germination and postseminal development are important. In this study the seeds were germinated in growth chamber under controled conditions and in the laboratory under light and dark conditions. For each treatment four repetitions of 25 seeds on Petri plates with humid filter paper were used. The results show that the seeds of S. elegans and S. niveus are positive photoblastic. The post-seminal development stages are the same for both species and during the germination period the undifferentiated axis of the embryo becomes apparent. The observation of the development of this axis shows that the growth of the leaves occurs first than that of the adventitious root. The seed operculum adheres to the testa and the primary root degenerates in the embrionary axis.
25 citations
TL;DR: This is a floristic survey of the Bignoniaceae, tribe Tecomeae, of the Espinhaco Range, which includes a range of mountains, with altitudes between 800-1800 m whose vegetation is mainly composed of "campos rupestres".
Abstract: This is a floristic survey of the Bignoniaceae, tribe Tecomeae, of the Espinhaco Range. This area includes a range of mountains, in the states of Bahia and Minas Gerais, with altitudes between 800-1800 m whose vegetation is mainly composed of "campos rupestres". The tribe is represented in the area by 17 species, distributed in 4 genera: Zeyheria (2 spp.), Tabebuia (6 spp.), Jacaranda (8 spp.) and Cybistax (1 sp.). Keys to genera and species, descriptions, illustrations and are presented comments. J. oxyphylla is reduced to the synonymy of J. caroba and J. morii is reduced to the synonymy of J. ulei.
21 citations
TL;DR: This research included a review of the literature, study of hebarium specimens, collection and observation of populations in the field, and resulted in the recognition of fourteen taxa, eleven species and three varieties.
Abstract: This research included a review of the literature, study of hebarium specimens, collection and observation of populations in the field. Taxonomic decisions were based on external morphology, and resulted in the recognition of fourteen taxa, eleven species and three varieties. Analytical keys for species and varietes, descriptions, illustrations and data on their geographical distribution, habitat and phenology are provided.
19 citations
TL;DR: Twelve species of Myxomycetes found on dead leaves, spathes and stipitis of Acrocomia intumescens Drude, Copernicea prunifera (Mill.) H. Moore, Mauritia flexuosa Mart.
Abstract: As palmeiras oferecem um ecossistema especializado que abriga organismos variados, incluindo Myxomycetes. Este trabalho relata doze especies de Myxomycetes encontradas em folhas mortas, espata e estipe de Acrocomia intumescens Drude (macauba), Copernicea prunifera (Mill.) H. E. Moore (carnauba), Mauritia flexuosa Mart, (buriti) e Orbygnia phalerata Mart, (babacu). Constitui-se area de coleta o Municipio do Crato, Ceara, Nordeste do Brasil (7o 30'00" S, 39o 00' 00" W, 400-1200 m de altitude). Coletas aleatorias foram efetuadas e as frutificacoes foram pesquisadas em orgaos vivos ou mortos das palmeiras. Exsicatas foram depositadas no Herbario UFP (Departamento de Botânica da Universidade Federal de Pernambuco, Recife - PE, Brasil). As especies registradas pertencem aos generos Ceratiomyxa (1), Dictydium (1), Arcyria (1), Hemitrichia (1), Badhamia (1), Fuligo (1), Physarum (3), Stemonitis (2) e Comatricha (1). Ceratiomyxa fruticulosa (Miill.) Macbr., Physarum stellatum (Mass.) Mart., Stemonitis pallida Win. e Comatricha typhoides (Bull.) Rost. sao referidas pela primeira vez para este tipo de substrato. Este trabalho eleva para 35 o numero de especies de Myxomycetes assinaladas sobre palmeiras ate o momento.
17 citations
TL;DR: This work presents an inventory of the species of the genus Zornia J.F.Gmel.
Abstract: Este trabalho teve como objetivo levantar e estudar as especies do genero Zornia J.F.Gmel. que ocorrem no Estado de Sao Paulo. Foi confirmada a ocorrencia de 9 especies: Zornia gardneriana Moric., Z. virgata Moric., Z. cryptantha Arechav., Z. ramboiana Mohlenbr., Z. glabra Desv., Z. reticulata Sm., Z. latifolia Sm., Z. curvata Mohlenbr. e Z gemella (Willd.) Vogel. Zornia paniculata N.F. Mattos foi considerada sinonimo de Z virgata. Para as especies foi confeccionada uma chave para identificacao, descricoes, comentarios, ilustracoes e mapas de distribuicao geografica.
15 citations
TL;DR: Phenological studies of three Paepalanthus sect.
Abstract: Phenological studies of three Paepalanthus sect. Actinocephalus species were done - P. hilairei, P. polyanthus and P. robustus. Monthly expeditions for 21 months to Serra do Cipo, Minas Gerais, Brazil were realized. It was detected that P. hilairei and P. robustus are perennial plants and P. polyanthus is a biennial plant. All of them present the blooming period mainly in Summer. Smell occurrence is registred in Paepalanthus for the first time.
14 citations
TL;DR: In a caatinga area, located in Agrestina - PE were identified 13 species of Bryophyte, distributed in the following families Frullaniaceae, Lejeuneaceae, Ricciaceae - Hepaticopsida - Bryaceae, Dicranaceae, Ephemeraceae, Fissidentaceae, leucobryaceae, Pottiaceae e Stereophyllaceae - Bryopsida.
Abstract: In a caatinga area, located in Agrestina (Lat 8o27'28"S; Long 35o57'13"W) - PE were identified 13 species of Bryophyte, distributed in the following families Frullaniaceae, Lejeuneaceae, Ricciaceae - Hepaticopsida - Bryaceae, Dicranaceae, Ephemeraceae, Fissidentaceae, Leucobryaceae, Pottiaceae e Stereophyllaceae - Bryopsida Cololejeunea minutissima (Sm) Schiffn and Riccia brasiliensis Schiffn are new records for the Northeast region, while Frullania dusenii Steph represents a new record for the Pernambuco State
TL;DR: The present research is a survey of the genus Diplazium Sw.
Abstract: The present research is a survey of the genus Diplazium Sw. (Dryopteridaceae) in the Parana State. The delimitation of the species was based on morphological characters and it was possible to recognize 11 species with the obtained data. Identification Key for the species, descriptions, comments, geographycal distribution and illustrations are presented.
TL;DR: E proposta uma nova combinacao para o genero Epidendrum L: E. Barros, e a sinonimizacao de Hexadesmia cearensis Schltr.
Abstract: E proposta uma nova combinacao para o genero Epidendrum L.: E. secundum var. albescens (Pabst) F. Barros, e a sinonimizacao de Hexadesmia cearensis Schltr. com Scaphy glottis fusiformis (Griseb.) Schultes; tres novas ocorrencias sao citadas para o Brasil: Platy stele stenostachya (Rchb. f.) Garay, Pleurothallis blaisdellii S. Wats, e Pleurothallis navicularis Lindl. E apresentada uma ilustracao de Epidendrum dichaeoides Carnevalli & Romero.
TL;DR: In this paper, a partir de tratamentos numericos analiticos, as informacoes mutuas for cada especie em relacao a variaveis ambientais evidencia grupos ecologicos distintos, caracterizados by seus padroes de reparticao espacial.
Abstract: Sao relacionadas as 60 principais especies vegetais dominantes do Arquipelago de Fernando de Noronha, no Nordeste brasileiro: 33 herbaceas, 12 lenhosas baixas ( 2 metros). A partir de tratamentos numericos analiticos, as informacoes mutuas para cada especie em relacao a variaveis ambientais evidencia grupos ecologicos distintos, caracterizados por seus padroes de reparticao espacial. As plantas com padrao de reparticao espacial definido dividem-se em especies ubiquistas, de sotavento, de barlavento, costeiras, de areas interiores, de areas florestadas e de ocorrencia isolada. As plantas com padrao pouco definido sao classificadas mais por sua funcao na paisagem que pelo modo de reparticao espacial nas ilhas e ilhotas. Sao as jitiranas, as invasoras e as especies plantadas ou ornamentais.
TL;DR: Paepalanthus polyanthus exhibits high mortality after inundation and in higher sand dune areas lower emergence and seedling survival are observed, mainly in periods of low pluviosity, and a negative association with Ischaemum minus is suggested.
Abstract: The distribution Pattern of Paepalanthus polyanthus was surveved in relation to topography variation and associated vegetation cover in a sand dune slack. Praia da Joaquina, Florianopolis, State of Santa Catarina, Brazil. Quadrats of 0.5 m2 were settled continuously along 4 line transects. The density of P. polyanthus, the percentage cover and the predominant species were determined in each quadrat. P. polyanthus showed a contagious pattern of distribution (Dispersion index of Morisita Id>1, P<0.001) in all transects. The individual were concentrated in intermediary areas of the microrelief. P. polyanthus was not observed at elevated sand dune areas, also characterized by lower percentage cover. At lake shores and flooded sites its density was low or the species absent. The factors limiting the distribution of P. polyanthus are discussed on aspects of its population dynamics. P. polyanthus exhibits high mortality after inundation and in higher sand dune areas lower emergence and seedling survival are observed, mainly in periods of low pluviosity. A negative association with Ischaemum minus is suggested and possibly explained by eventual floods or by interference of the dense cover of this grass species on germination and growth of P. polyanthus.
TL;DR: Senna macranthera seedlings were more sensitive to osmotic stress, reducing shoot and radicle elongation when levels of external water stress were increased, and results suggest a limit of tolerance between the Osmotic potentials of -0.49 and -1.03MPa.
Abstract: Sementes de Senna macranthera, S. multijuga e Mimosa bimucronata foram submetidas a diferentes potenciais osmoticos simulados com PEG 6000 (0; -0,15; -0,49; -1,03 MPa) com o objetivo de avaliar o efeito do estresse hidrico na germinacao e crescimento inicial de plântulas. Os potenciais osmoticos de -0,15 e -0,49MPa causaram um retardo de 12, 24 e 48 horas no inicio da germinacao de M. bimucronata, S. multijuga e S. macranthera, respectivamente. Em todas as especies, a germinabilidade final das sementes submetidas ao Ψ = -0,49MPa foi reduzida e nenhuma semente germinou em solucao de Ψ = -1,03MPa. Estes resultados indicam um limite de tolerância entre os potenciais -0,49 e -1,03MPa. Plântulas de S. macranthera mostraram-se mais sensiveis ao estresse hidrico, reduzindo comprimentos de parte aerea e radicula a medida que os potenciais osmoticos tornavam-se mais negativos. Plântulas de S. multijuga e M. bimucronata apresentaram um aumento no comprimento medio da radicula em solucao de Ψ= -0,15MPa. Houve reducao do peso seco das plântulas a partir do Ψ = -0,49MPa para as 3 especies testadas.
TL;DR: Development of the pollen and anther wall of Tabebuia ochracea was studied and the conspicuous growing of the nucleolus and nucleolar vacuolation into the generative cell sugests a high biosynthetic activity.
Abstract: Development of the pollen and anther wall of Tabebuia ochracea was studied. The microsporangial wall follows the Dicotyledoneous type of ontogeny. The sporogenous tissue in each microsporangium, in transverse section, is organized in a celular strip, with a horseshoe outline. The tapetum is secretory and shows a distinct dual origin. The inner tapetai layer differentiates earlier than the outher layer. The two tapetai layers exibit a distinct structural dimorphism, but before the meiotic divisions of the MMCs the tapetai layers become identical. Vacuolation in each tapetai cell, at this stage, is characteristically bipolar. The endothecium shows fibrous thickenings of the spiral type. The pollen grain development conforms with the usual way in angiosperms. The conspicuous growing of the nucleolus and nucleolar vacuolation into the generative cell sugests a high biosynthetic activity.
TL;DR: The cerrado species showed a tendency to higher contents of epicuticular waxes and lower proportion of hydrocarbons than the forest species, and the ecological and taxonomic aspects are discussed.
Abstract: Especies de cerrado e mata foram analisadas quanto a sua composicao em ceras foliares epicuticulares e de seus componentes hidrocarbonetos. Observou-se nas especies de cerrado uma tendencia a teores de ceras pouco maiores que os de especies de mata estacionai semidecidua. A porcentagem de hidrocarbonetos nas ceras foi maior na maioria das especies de mata que nas especies congeneres de cerrado. Pela analise em CG, os hidrocarbonetos mostraram predominância de C29 e C31 apresentando um comprimento medio da cadeia de carbono dos homologos menos variavel em especies de mata, em torno de 30,5, que de cerrado nas quais este valor variou de 28,5 a 31,3. Os resultados sao discutidos em relacao ao provavel papel ecologico das ceras e sua aplicacao como marcadores taxonomicos.
TL;DR: E descrita uma nova especie para o genero Calyptranthes (Myrtaceae), ocorrente na Reserva Biologica do Tingua, municipio de Nova Iguacu, Rio de Janeiro, que tem aptidao ornamental como arvoreta para areas sombreadas.
Abstract: E descrita uma nova especie para o genero Calyptranthes (Myrtaceae), ocorrente na Reserva Biologica do Tingua, municipio de Nova Iguacu, Rio de Janeiro. Trata-se de arvore ou arvoreta do estrato intermediario ou inferior da floresta atlântica que se destaca pela pilosidade densa e rufa de seus raminhos, peciolos e dorso foliar. Pela sua forma de crescimento com copa pequena e arredondada e beleza de seus ramos esfoliantes, a nova especie tem aptidao ornamental como arvoreta para areas sombreadas.
TL;DR: Nomenclatural and taxonomic changes are proposed in Xyris; one new status and two new synonym are proposed.
Abstract: Sao propostas alteracoes nomenclaturais e taxonomicas em Xyris, status novum e dois novos sinonimos.