Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: 

RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 59
Primeira ... 123 ... Última
Imagem não selecionada

Imprime registro no formato completo
Are the genera Hallea and Mitragyna (Rubiaceae-Coptosapelteae) pollen morphologically distinct? Naturalis
Huysmans, S.; Robbrecht, E.; Smets, E..
Recent literature is controversial as regards the segregation of Hallea and Mitragyna, and pretends that the two genera show pollen morphological differences. In the present study the pollen morphology of all ten species of the complex is described on the basis of light and scanning electron microscopy (including examination of broken grains, which were obtained with a technique never applied in palynology, viz. shaking with glass beads). The two genera have 3-zonocolporate grains with compound apertures (endoapertures are always H-shaped, sometimes incompletely so). While Hallea showed to be stenopalynous (sexine always tectate-perforate), Mitragyna is more variable (sexine microreticulate or tectate-perforate), and several of its species have pollen...
Tipo: Article / Letter to the editor
Ano: 1994 URL: http://www.repository.naturalis.nl/record/524503
Imagem não selecionada

Imprime registro no formato completo
Pollen morphological variation in Vanguerieae (Ixoroideae - Rubiaceae) Naturalis
Lens, F.; Jansen, S.; Huysmans, S.; Robbrecht, E.; Smets, E..
The Vanguerieae is a large tribe of the subfamily Ixoroideae (Rubiaceae) and consists of about 500 species in 27 genera. This study gives a detailed pollen morphological description of 30 species from 16 genera, based on light microscopy and scanning electron microscopy. The Vanguerieae are considered to be stenopalynous, although there is some evidence to question this. First, there is a difference in sexine types that clearly de® nes Keetia and Psydrax ( both reticulate) , and Canthium and Vanguerieae (both perforate with very small perforations) from the other Vanguerieae investigated. Second, pollen grains corroborate the subgeneric delimitations of Canthium sensu Bridson. Pollen morphologically the tribe is characterised by ( 1) the shape of the...
Tipo: Article / Letter to the editor Palavras-chave: Vanguereae; Ixoroideae; Rubiaceae; Pollen; Morphological variation; Stenopalynous; 42.58.
Ano: 2000 URL: http://www.repository.naturalis.nl/record/423771
Imagem não selecionada

Imprime registro no formato completo
Intervascular pit membranes with a torus in the wood of Ulmus (Ulmaceae) and related genera Naturalis
Jansen, S.; Choat, B.; Vinckier, S.; Lens, F.; Schols, P.; Smets, E..
• The distribution of intervascular pit membranes with a torus was investigated in juvenile wood samples of 19 species of Ulmus and seven related genera. • A staining solution of safranin and alcian blue (35 : 65) was recommended to distinguish torus-bearing pit membranes using light microscopy. • Intervascular pit membranes connecting relatively wide vessel elements resembled those of most angiosperms, as they were of uniform thickness. By contrast, bordered pit pairs with round to oval pit apertures and indistinct pit canals that connected narrow (incomplete) vessel elements or vascular tracheids with distinct helical thickenings were frequently characterized by a torus in ring-porous wood samples of Ulmus and Zelkova. Tori were lacking in...
Tipo: Article / Letter to the editor Palavras-chave: Ulmus (elm); Ulmaceae; Pit membrane; Torus; Pit structure; Wood anatomy; Tracheary elements; 42.58.
Ano: 2004 URL: http://www.repository.naturalis.nl/record/423388
Imagem não selecionada

Imprime registro no formato completo
Phylogeny of Cyperaceae based on DNA sequence data - a new rbcL analysis Naturalis
Simpson, D.A.; Muthama Muasya, A.; Alves, M.V.; Bruhl, J.J.; Dhooge, S.; Chase, M.W.; Furness, C.A.; Ghamkhar, K.; Goetghebeur, P.; Hodkinson, T.D.; Marchant, A.D.; Reznicek, A.A.; Nieuwborg, R.; Roalson, E.H.; Smets, E.; Starr, J.R.; Thomas, W.W.; Wilson, K.L.; Zhang, X..
Since the Monocots II meeting in 1998, significant new data have been published that enhance our systematic knowledge of Cyperaceae. Phylogenetic studies in the family have also progressed steadily. For this study, a parsimony analysis was carried out using all rbcL sequences currently available for Cyperaceae, including data for two new genera. One of the four subfamilies (Caricoideae) and seven of the 14 tribes (Bisboeckelereae, Cariceae, Cryptangieae, Dulichieae, Eleocharideae, Sclerieae, Trilepideae) are monophyletic. Subfamily Mapanioideae and tribe Chrysitricheae are monophyletic if, as the evidence suggests, Hellmuthia is considered a member of Cypereae. Some other features of our analysis include: well-supported Trilepideae and...
Tipo: Article / Letter to the editor Palavras-chave: Cyperaceae; Monocotyledons; Phylogeny; RbcL; Sequence; 42.48.
Ano: 2007 URL: http://www.repository.naturalis.nl/record/414071
Imagem não selecionada

Imprime registro no formato completo
Pollen of the Spermacoce (Rubiaceae) species from the Northern Territory of Australia: morphology and taxonomic significance Naturalis
Dessein, S.; Harwood, R.; Smets, E.; Robbrecht, E..
Complementary to the revision of the genus Spermacoce in the Northern Territory of Australia, pollen morphology of 48 of the 53 native Spermacoce species from the Northern Territory has been investigated by scanning electron and light microscopy. There is considerable variation for most diagnostic pollen characters. The average equatorial diameter (E) ranges from 10.5 to 41.7 μm. Grains are invariably colporate with apertures situated at the equator (being zonocolporate). The number of apertures varies from 3 to 17. The endoaperture is generally an endocingulum, often with a secondary thinning at the ectocolpus; one species has endocolpi. The sexine is usually perforate, but psilate, foveolate, and (micro)reticulate patterns were also found. Supratectal...
Tipo: Article / Letter to the editor Palavras-chave: Spermacoce; Rubiaceae; Pollen morphology; Palynology; Australia; Northern Territory.
Ano: 2005 URL: http://www.repository.naturalis.nl/record/407293
Imagem não selecionada

Imprime registro no formato completo
Hymenodictyeae (Rubiaceae – Cinchonoideae) and its phylogenetic significance Naturalis
Verellen, J.; Dessein, S.; Razafimandimbison, S.G.; Smets, E.; Huysmans, S..
The tribe Naucleeae has recently been recircumscribed on the basis of both morphological and molecular [rbcL, trnT-F, internal transcribed spacer (ITS)] evidence, and has been found to be the sister group of the tribe Hymenodictyeae Razafim. & B. Bremer. In order to find pollen morphological support for this new classification, the pollen and orbicules of 65 species, representing 23 Naucleeae and the two Hymenodictyeae genera, were investigated by scanning electron and light microscopy. Naucleeae pollen is very small (< 20 µm) to small (20–30 µm) and its shape in equatorial view is suboblate to spheroidal or, more rarely, subprolate. Three compound apertures are present, each comprising a long and narrow ectocolpus, a circular to slightly lolongate...
Tipo: Article / Letter to the editor Palavras-chave: Compound apertures; Endoapertures; Orbicule morphology; Palynology; Sexine ornamentation; 42.48.
Ano: 2007 URL: http://www.repository.naturalis.nl/record/422226
Imagem não selecionada

Imprime registro no formato completo
Insular woodiness on the Canary Islands: a remarkable case of convergent evolution Naturalis
Lens, F.; Davin, N.; Smets, E.; Arco, M. del.
Premise of research. One of the most conspicuous aspects of island floras is the relatively high proportion of woody species. Often, but not always, these woody species have developed wood on the islands and have evolved from herbaceous continental ancestors, a phenomenon known as insular woodiness. Shifts from herbaceousness toward increased woodiness also occur on continents (the broader term “secondary woodiness” is more appropriate here and includes insular woodiness), but comprehensive worldwide knowledge about secondary woodiness within angiosperms remains lacking. We update hypotheses regarding the herbaceous ancestry of woody Canarian lineages in a molecular phylogenetic context and investigate the possible link of secondary woodiness and...
Tipo: Article / Letter to the editor Palavras-chave: Canary Islands convergent evolution insular woodiness molecular phylogeny protracted juvenilism seconday woodinessq wood anatomy 42.21; 42.44.
Ano: 2013 URL: http://www.repository.naturalis.nl/record/453855
Imagem não selecionada

Imprime registro no formato completo
What shapes amino acid and sugar composition in Mediterranean floral nectars? Naturalis
Petanidou, T.; Van Laere, A.; Ellis, W.; Smets, E..
We studied the amino acid (AA) composition of the floral nectars of 73 plant species occurring in a phryganic (East Mediterranean garrigue) community and investigated whether AA and sugar composition is shaped by evolutionary (plant phylogeny), ecological (flowering time as a direct effect of summer drought) and coevolutionary (pollinator partnership) constraints. Our study utilised an extensive plantpollinator matrix compiled in the same area where the plants had been sampled. Using HPLC we detected 22 AA compounds/groups of compounds, out of which 15 were commonly present in almost all nectars. Among all AAs, phenylalanine was the most abundant, especially in keystone (‘‘cornucopian’’) plant species visited by many insect species, such as the...
Tipo: Article / Letter to the editor Palavras-chave: Floral nectar; Composition; Mediterranean; Evolution; Ecology; Coeveloution.
Ano: 2006 URL: http://www.repository.naturalis.nl/record/407342
Imagem não selecionada

Imprime registro no formato completo
Palynological Variation in Balsaminoid Ericales. I. Marcgraviaceae Naturalis
Lens, F.; Dressler, S.; Vinckier, S.; Janssens, S.; Dessein, S.; Van Evelghem, L.; Smets, E..
Background and Aims Marcgraviaceae are a rather small family of seven genera and approx. 130 neotropical species. This study aims to present a detailed palynological survey of the family in order to comment on the intrafamily relationships and possible correlations with pollinators. Methods In total, 119 specimens representing 67 species and all genera are observed using light microscopy and scanning electron microscopy. Furthermore, eight species from five genera are studied with transmission electron microscopy. Key Results Our results show that pollen grains of Marcgraviaceae are small (20–35 mm), have three equatorial apertures, granules on the colpus membrane, oblate spheroidal to prolate spheroidal shapes, mainly psilate to perforate ornamentations,...
Tipo: Article / Letter to the editor Palavras-chave: Balsaminoids; Ericales; Marcgraviaceae; Neotropics; Orbicules; Palynology; SEM; TEM.
Ano: 2005 URL: http://www.repository.naturalis.nl/record/407283
Imagem não selecionada

Imprime registro no formato completo
Description of 11 new Astiella (Spermacoceae, Rubiaceae) species endemic to Madagascar Naturalis
Groeninckx, I.; Janssens, S.; Smets, E.; Verstraete, B..
Astiella is an herbaceous genus endemic to Madagascar, originally described with a single species A. delicatula Jovet. Molecular and morphological evidence place it in the tribe Spermacoceae s. lat. of Rubiaceae. During herbarium studies and fieldwork in Madagascar, 11 new Astiella species were identified and these are described here: A. antongilensis Groeninckx sp. nov., A. antsalovansis Groeninckx sp. nov., A. confusa Groeninckx sp. nov., A. deblockiae Groeninckx sp. nov., A. desseinii Groeninckx sp. nov., A. homolleae Groeninckx sp. nov., A. latifolia Groeninckx sp. nov., A. longifimbria Groeninckx sp. nov., A. perrieri Groeninckx sp. nov., A. pulla Groeninckx sp. nov., and A. tsaratanensis Groeninckx sp. nov. The genus Astiella now holds 12 species in...
Tipo: Article / Letter to the editor Palavras-chave: Astiella; Endemism; Madagascar; Rubiaceae; Spermacoceae s. lat..
Ano: 2017 URL: http://www.repository.naturalis.nl/record/629097
Imagem não selecionada

Imprime registro no formato completo
Floral Ontogeny in Scirpus, Eriophorum and Dulichium (Cyperaceae), with Special Reference to the Perianth Naturalis
Vrijdaghs, A.; Caris, P.; Goetghebeur, P.; Smets, E..
Background and Aims Based on molecular phylogenetic analysis, it has been suggested recently that the Cyperaceae comprises only two subfamilies: the Mapanioideae and the Cyperoideae. In most flowers of the Cyperoideae, the whorl of inner stamens is reduced, resulting in tetracyclic flowers. In the more primitive (scirpoid) genera within the Cyperoideae, the perianth consists of two polysymmetric whorls, whereas the perianth parts in the more derived genera have been subject to modifications and/or reduction. Comparative studies of the many silky hairs of Eriophorum and of the eight bristles of Dulichium have given rise to much discussion about their homology. Methods The spikelet and floral ontogeny in freshly collected inflorescences was investigated...
Tipo: Article / Letter to the editor Palavras-chave: Dulichium arundinaceum (L.) Britton; Eriophorum latifolium Hoppe; Floral ontogeny; Perianth; Scirpoid flower; Scirpus sylvaticus L; Scanning electron microscopy.
Ano: 2005 URL: http://www.repository.naturalis.nl/record/407290
Imagem não selecionada

Imprime registro no formato completo
Palynological Variation in Balsaminoid Ericales. II. Balsaminaceae, Tetrameristaceae, Pellicieraceae and General Conclusions Naturalis
Janssens, S.; Lens, F.; Dressler, S.; Geuten, K.; Smets, E.; Vinckier, S..
Background and Aims The objective of this study is to examine the palynological diversity of Balsaminaceae (two genera/61000 species), Tetrameristaceae (two genera/two species) and Pellicieraceae (one genus/one species). The diversity found will be used to infer the systematic value of pollen features within the balsaminoid clade. Methods Pollen morphology and ultrastructure of 29 species, representing all families of the balsaminoid clade except Marcgraviaceae, are investigated by means of light microscopy, scanning electron microscopy and transmission electron microscopy. Key Results Balsaminaceae pollen is small to medium sized with three to four apertures, which can be either colpate or porate, and a sexine sculpturing varying from coarsely...
Tipo: Article / Letter to the editor Palavras-chave: Balsaminaceae; Ericales; Orbicules; Pellicieraceae; Pollen; SEM; TEM; Tetrameristaceae.
Ano: 2005 URL: http://www.repository.naturalis.nl/record/407278
Imagem não selecionada

Imprime registro no formato completo
Comparative Wood Anatomy of the Primuloid Clade (Ericales s.l.) Naturalis
Lens, F.; Jansen, S.; Caris, P.; Serlet, L.; Smets, E..
The wood structure of 78 species from 27 genera representing the woody primuloids (Maesaceae, Myrsinaceae, and Theophrastaceae) was investigated using light microscopy (LM) and scanning electron microscopy (SEM). Results indicated that the ray structure, the nature of mineral inclusions, and the occurrence of breakdown areas in rays can be used to separate the three primuloid families from each other. Within Ericales, the presence of exclusively multiseriate rays is synapomorphic for Myrsinaceae and Theophrastaceae, and the occurrence of breakdown areas in rays is synapomorphic for Myrsinaceae. Within Myrsinaceae, the wood structure of the mangrove genus Aegiceras differs because it has short vessel elements that are storied, non-septate fibers, a...
Tipo: Article / Letter to the editor Palavras-chave: Primuloids; Ericales s.l.; Maesaceae; Myrsinaceae; Theophrastaceae; Wood anatomy; Comparison; Light microscopy; Scanning electron microscopy.
Ano: 2005 URL: http://www.repository.naturalis.nl/record/407307
Imagem não selecionada

Imprime registro no formato completo
The tribal placement of the monospecific tropical African genus Petitiocodon (Rubiaceae) based on molecular data and morphology Naturalis
Tosh, J.; De Block, P.; Davis, A.P.; Dessein, S.; Robbrecht, E.; Smets, E..
A first phylogenetic placement of Petitiocodon based on molecular sequence data from three plastid regions (accD-psa1, rpl16 and trnL-F) is presented, in conjunction with a reassessment of morphology for the genus. Our results do not support an evolutionary affinity between Petitiocodon and Tricalysia (Coffeeae) as suggested by previous studies, but they confirm other research that Petitiocodon and Didymosalpinx are distinct genera. Placement of Petitiocodon in tribe Octotropideae is well-supported on the basis of molecular data and floral and carpological characters.
Tipo: Article / Letter to the editor Palavras-chave: Octotropideae; African flora; AccD-PSA1; Rpl16; TrnL-F; Molecular phylogenetics; Placentation; 42.58.
Ano: 2008 URL: http://www.repository.naturalis.nl/record/449521
Imagem não selecionada

Imprime registro no formato completo
A comparison of paraffin and resin-based techniques used in bark anatomy Naturalis
Hamann, T.; Smets, E.; Lens, F..
Bark anatomy is an unappreciated discipline in plant systematics, despite its great potential to reveal systematically informative features. In this paper, main reasons for the lack of detailed bark anatomical data in many plant families are identified, including problems with sectioning, terminological issues, and difficulties in observation of dilated stems. We deal with these problems by focusing on two aspects: (1) compare, discuss and improve existing sectioning and maceration techniques using two species with soft and hard bark tissues; and (2) discuss the best way to collect stem bark samples. We hope that this paper will stimulate inclusion of bark anatomical data in future systematic studies.
Tipo: Article / Letter to the editor Palavras-chave: Bark anatomy; Light microscopy; Macerations; Plant systematics; Phloem; Sectioning; 42.54.
Ano: 2011 URL: http://www.repository.naturalis.nl/record/421834
Imagem não selecionada

Imprime registro no formato completo
The multiple fuzzy origins of woodiness within Balsaminaceae using an integrated approach. Where do we draw the line? Naturalis
Lens, F.; Eeckhout, S.; Zwartjes, R.; Smets, E.; Janssens, S.B..
• Background and Aims: The family Balsaminaceae is essentially herbaceous, except for some woodier species that can be described as ‘woody’ herbs or small shrubs. The family is nested within the so-called balsaminoid clade of Ericales, including the exclusively woody families Tetrameristaceae and Marcgraviaceae, which is sister to the remaining families of the predominantly woody order. A molecular phylogeny of Balsaminaceaeis compared with wood anatomical observations to find out whether the woodier species are derived from herbaceous taxa (i.e. secondary woodiness), or whether woodiness in the family represents the ancestral state for the order (i.e. primary woodiness). • Methods: Wood anatomical observations of 68 Impatiens species and Hydrocera...
Tipo: Article / Letter to the editor Palavras-chave: Balsaminaceae; Herbaceousness; Hydrocera; Impatiens; Insular woodiness; Light microscopy; Secondary woodiness; Wood anatomy; 42.56.
Ano: 2012 URL: http://www.repository.naturalis.nl/record/429514
Imagem não selecionada

Imprime registro no formato completo
Floral Ontogeny in Ficinia and Isolepis (Cyperaceae), with Focus on the Nature and Origin of the Gynophore Naturalis
Vrijdaghs, H.; Goetghebeur, P.; Muasya, A.M.; Caris, P.; Smets, E..
! Background and Aims The generic delimitations of Ficinia and Isolepis, sister genera in the Cypereae, are blurred. Typical Ficinia flowers have a lobed gynophore, which envelops the base of the nutlet, whereas in Isolepis the character is considered to be absent. Some former species of Isolepis, lacking the gynophore, were recently included in Ficinia. The floral ontogeny of representative taxa in Ficinia and Isolepis were investigated with the aim of evaluating the origin and nature of the gynophore in the Cypereae. ! Methods The spikelet and floral ontogeny in inflorescences collected in the field was investigated using scanning electron microscopy (SEM) and light microscopy (LM). ! Key Results SEM images of Isolepis setacea and I. antarctica, Ficinia...
Tipo: Article / Letter to the editor Palavras-chave: Ficinia; Floral ontogeny; Gynophore; Isolepis; Scanning electron microscopy.
Ano: 2005 URL: http://www.repository.naturalis.nl/record/407286
Imagem não selecionada

Imprime registro no formato completo
The distribution and phylogeny of aluminium accumulating plants in the Ericales Naturalis
Jansen, S.; Watanabe, T.; Caris, P.; Geuten, K.; Lens, F.; Pyck, N.; Smets, E..
The distribution of aluminium (Al) accumulation in the Ericales is surveyed, based on semi-quantitative tests of 114 species and literature data. Al accumulation mainly characterises the families Diapensiaceae, Pentaphylacaceae, Symplocaceae, Ternstroemiaceae, and Theaceae. Al accumulation is consistently present or absent in most families examined, but the character appears to be more variable in a few taxa (e.g., Lecythidaceae, Myrsinaceae). Although the interfamilial relationships within the Ericales require further research, the ability to accumulate high levels of Al appears to show considerable taxonomic significance. While the majority of Al accumulating Ericales includes woody, tropical plants, the feature is remarkably present in several...
Tipo: Article / Letter to the editor Palavras-chave: Aluminium accumulation; Ericales; Phyogeny; Diapensiaceae; Pentaphylacaceae; Symplocaceae; Ternstroemiaceae; Theaceae; 42.56.
Ano: 2004 URL: http://www.repository.naturalis.nl/record/431739
Imagem não selecionada

Imprime registro no formato completo
Comparative wood anatomy of epacrids (Styphelioideae, Ericaceae s.l.) Naturalis
Lens, F.; Gasson, P.; Smets, E.; Jansen, S..
The wood anatomy of 16 of the 37 genera within the epacrids (Styphelioideae, Ericaceae s.l.) is investigated by light and scanning electron microscopy. Several features in the secondary xylem occur consistently at the tribal level: arrangement of vessel‐ray pits, distribution of axial parenchyma, ray width, and the presence and location of crystals. The primitive nature of Prionoteae and Archerieae is supported by the presence of scalariform perforation plates with many bars and scalariform to opposite vessel pitting. The wood structure of Oligarrheneae is similar to that of Styphelieae, but the very narrow vessel elements, exclusively uniseriate rays and the lack of prismatic crystals in Oligarrheneae distinguish these two tribes. The secondary xylem of...
Tipo: Article / Letter to the editor Palavras-chave: Ecological wood anatomy; Epacrids; Ericaceae s.l.; Styphelioideae; Systematic wood anatomy; 42.56.
Ano: 2003 URL: http://www.repository.naturalis.nl/record/431740
Registros recuperados: 59
Primeira ... 123 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional