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| Registros recuperados: 26 | |
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| Lens, F.; Baas, P.; Jansen, S.; Smets, E.. |
| The wood structure of 71 species representing 24 genera of the pantropical Lecythidaceae s.l., including the edible Brazil nuts (Bertholletia excelsa) and the spectacular cannon-ball tree (Couroupita guianensis), was investigated using light and scanning electron microscopy. This study focused on finding phylogenetically informative characters to help elucidate any obscure evolutionary patterns within the family. The earliest diverging subfamily Napoleonaeoideae has mixed simple/scalariform vessel perforations, scalariform vessel-ray pitting, and high multiseriate rays, all features that are also present in Scytopetaloideae. The wood structure of Napoleonaea is distinct, but its supposed close relative Crateranthus strongly resembles Scytopetaloideae. The... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Ericales; Lecythidaceae s.l.; Lecythidaceae s.s.; Napoleonaeaceae; Scytopetalaceae; Systematic wood anatomy; 42.48. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/422216 |
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| Lens, F.; Smets, E.; Jansen, S.. |
| The wood anatomical structure of 11 out of 13 genera from four tribes of the Vaccinioideae, namely Andromedeae s.s., Gaultherieae, Lyonieae and Oxydendreae (Ericaceae s.l.), is described using light and scanning electron microscopy. Several features of the secondary xylem support the tribal classification based on molecular data: arrangement of vessel-ray pitting, height of multiseriate rays and the shape of the body ray cells. Oxydendreae are clearly defined from the other representatives by various wood anatomical features. Gaultherieae can be distinguished from Lyonieae by differences in vessel perforation plates, vessel-ray pitting, height and structure of multiseriate rays, and occurrence of prismatic crystals, but the wood of Andromedeae s.s. is... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Comparative wood anatomy; Andromedeae; Gaultherieae; Lyonieae; Oxydendreae; Vaccinioideae; Ericaceae; Andromedeae sensu Stevens; Pith structure; 42.58. |
| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/424620 |
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| Lens, F.; Endress, M.E.; Baas, P.; Jansen, S.; Smets, E.; , D.. |
| This study contributes to our understanding of the phylogenetic signifi cance and major evolutionary trends in the wood of the dogbane family (Apocynaceae), one of the largest and economically most important angiosperm families. Based on LM and SEM observations of 56 Apocynoideae species — representing all currently recognized tribes — and eight Periplocoideae, we found striking differences in vessel grouping patterns (radial multiples vs. large clusters) between the mainly nonclimbing apocynoid tribes (Wrightieae, Malouetieae, Nerieae) and the climbing lineages (remaining Apocynoideae and Periplocoideae). The presence of large vessel clusters in combination with fibers in the ground tissue characterizing the climbing Apocynoideae and Periplocoideae... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Apocynaceae; Apocynoideae; APSA clade; Climbing vs. nonclimbing anatomy; Periplocoideae; Systematic wood anatomy; Tribal classification; 42.58. |
| Ano: 2009 |
URL: http://www.repository.naturalis.nl/record/424670 |
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| Lens, F.; Dressler, S.; Jansen, S.; Van Evelghem, L.; Smets, E.. |
| Wood samples of 49 specimens representing 31 species and 11 genera of woody balsaminoids, i.e., Balsaminaceae, Marcgraviaceae, Pellicieraceae, and Tetrameristaceae, were investigated using light microscopy and scanning electron microscopy. The wood structure of Marcgraviaceae, Pellicieraceae, and Tetrameristaceae is characterized by radial vessel multiples with simple perforation plates, alternate vessel pitting, apotracheal and paratracheal parenchyma, septate libriform fibers, and the presence of raphides in ray cells. Tetrameristaceae and Pellicieraceae are found to be closely related based on the occurrence of unilaterally compound vessel-ray pitting and multiseriate rays with long uniseriate ends. The narrow rays in Pelliciera are characteristic of... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Balsaminaceae; Balsaminoid clade; Ericales; Marcgraviaceae; Paedomorphism; Pellicieraceae; Tetrameristaceae; Wood anatomy; 42.40. |
| Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/407273 |
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| Jansen, S.; Gortan, E.; Lens, F.; Assunta Lo Gullo, M.; Salleo, S.; Scholtz, A.; Stein, A.; Trifilò, P.; Nardini, A.. |
| • The hydraulic conductance of angiosperm xylem has been suggested to vary with changes in sap solute concentrations because of intervessel pit properties. • The magnitude of the ‘ionic effect’ was linked with vessel and pit dimensions in 20 angiosperm species covering 13 families including six Lauraceae species. • A positive correlation was found between ionic effect and vessel grouping parameters, especially the portion of vessel walls in contact with neighbouring vessels. Species with intervessel contact fraction (FC) values < 0.1 showed an ionic effect between 2% and 17%, while species with FC values > 0.1 exhibited a response between 10% and 32%. The ionic effect increased linearly with the mean fraction of the total vessel wall area occupied... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Angiosperms; Hydraulic conductivity; Intervessel pit membrane; Ionic effect; Vessel grouping; Wood anatomy; 42.41. |
| Ano: 2011 |
URL: http://www.repository.naturalis.nl/record/423644 |
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| Lens, F.; Luteyn, J.L.; Smets, E.; Jansen, S.. |
| The ecological wood anatomy of 128 vaccinioid wood samples (including 115 species, 35 genera), collected between 39°S and 60°N latitude and 10 m to 3400 m altitude is studied. Several wood anatomical features within the subfamily, viz. tangential vessel diameter, average length of tracheary elements, height of multiseriate rays, and presence of prismatic crystals are negatively correlated with increasing latitude, while vessel density and helical thickenings show a positive correlation with increasing latitude. Similar latitudinal trends are found within the genus Vaccinium (31 species studied). The correlation between various wood anatomical features and latitude is surprisingly high despite the fact that most tropical species grow in montane regions,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Altitude; Ecological and functional wood anatomy; Ericaceae; Latitude; Vaccinioideae; Vaccinium; 42.58. |
| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/424624 |
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| Jansen, S.; Lens, F.; Ntore, S.; Piesschaert, F.; Robbrechf, E.; Smets, E.. |
| The secondary xylem of Craterispermeae, Coussareeae, Morindeae s.str., Prismatomerideae, Pauridiantheae, Urophylleae, and Triainolepideae (Rubiaceae, Rubioideae) is described and illustrated in detail. Genera that were previously placed in the Morindeae or Psychotrieae such as Damnacanthus, Lasianthus, Saldinia, and Trichosfachys are also included. Wood anatomical characters are compared with recent phylogenetic insights into the study group on the basis of molecular data. The observations demonstrate that the delimitation and separation of several taxa from the former Coussareeae/Morindeae/Prismatomerideae/Psychotrieae aggregate is supported by wood anatomical data. The Coussareeae can be distinguished from the other Rubioideae by their scanty parenchyma,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Rubiaceae; Rubioideae; Systematic wood anatomy; 42.58. |
| Ano: 2001 |
URL: http://www.repository.naturalis.nl/record/421859 |
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| Jansen, S.; Sano, Y.; Choat, B.; Rabaey, D.; Lens, F.; Dute, R.R.. |
| The micromorphology of pits in tracheary elements was examined in 35 species representing 29 genera of Rosaceae and related families to evaluate the assumption that angiosperm pits are largely invariant. In most Rosaceae, pit membranes between fibers and tracheids frequently appear to have amorphous thickenings with an irregular distribution. Although these structures are toruslike under the light microscope, observations by electron microscopy illustrate that they represent ‘‘pseudotori’’ or plasmodesmata-associated thickenings. These thickenings frequently extend from the periphery of the pit membrane and form a cap-like, hollow structure. Pseudotori are occasionally found in few Elaeagnaceae and Rhamnaceae and appear to be related to species with... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Fiber; Pit; Pit membrane; Pseudotorus; Rosaceae; Rosales; Torus; Tracheid; 42.58. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/423505 |
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| Rabaey, D.; Lens, F.; Huysmans, S.; Smets, E.; Jansen, S.. |
| Recent micromorphological observations of angiosperm pit membranes have extended the number and range of taxa with pseudo-tori in tracheary elements. This study investigates at ultrastructural level (TEM) the development of pseudo-tori in the unrelated Malus yunnanensis, Ligustrum vulgare, Pittosporum tenuifolium, and Vaccinium myrtillus in order to determine whether these plasmodesmata associated thickenings have a similar developmental pattern across flowering plants. At early ontogenetic stages, the formation of a primary thickening was observed, resulting from swelling of the pit membrane in fibre-tracheids and vesselelements. Since plasmodesmata appear to be frequently, but not always, associated with these primary pit membrane thickenings, it remains... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Ontogeny; Pseudo-torus; Tracheary element; Pit membrane; Bordered pit; Wood ultrastructure; 42.56. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/430078 |
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| Lens, F.; Endress, M.E.; Baas, P.; Jansen, S.; Smets, E.. |
| Wood anatomical studies in the economically important Apocynaceae or dogbane family are fragmentary. This study represents a first attempt to unravel the phylogenetic signifi cance and major evolutionary trends in the wood of the family, using existing and new microscopic wood observations within the large subfamily Rauvolfi oideae. On the basis of LM and SEM observations of 91 species representing all 10 currently recognized tribes, we found that most of the tribes are characterized by a unique combination of wood characters, such as vessel grouping, vessel element length, fi ber type, frequency of uniseriate rays, and fused multiseriate rays. Climbing rauvolfi oid taxa can generally be distinguished from erect species by their wider vessels, tendency to... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Apocynaceae; APSA clade; Climbing vs. nonclimbing habit; Rauvolfi oideae; Systematic wood anatomy; Tribal classification; 42.58. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/424647 |
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| Choat, B.; Jansen, S.; Brodribb, T.J.; Cochard, H.; Delzon, S.; Bhaskar, R.; Bucci, S.J.; Feild, T.S.; Gleason, S.M.; Hacke, U.G.; Jacobsen, A.L.; Lens, F.; Maherali, H.; Martínez-Vilalta, J.; Mayr, S.; Mencuccini, M.; Mitchell, P.J.; Nardini, A.; Pittermann, J.; Pratt, R.B.; Sperry, J.S.; Westoby, M.; Wright, I.J.; Zanne, A.E.. |
| Shifts in rainfall patterns and increasing temperatures associated with climate change are likely to cause widespread forest decline in regions where droughts are predicted to increase in duration and severity. One primary cause of productivity loss and plant mortality during drought is hydraulic failure. Drought stress creates trapped gas emboli in the water transport system, which reduces the ability of plants to supply water to leaves for photosynthetic gas exchange and can ultimately result in desiccation and mortality. At present we lack a clear picture of how thresholds to hydraulic failure vary across a broad range of species and environments, despite many individual experiments. Here we draw together published and unpublished data on the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Global convergence vulnerability forests drought climate change drought-induced forest decline 42.44; 43.47. |
| Ano: 2012 |
URL: http://www.repository.naturalis.nl/record/453830 |
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| Rabaey, D.; Huysmans, S.; Lens, F.; Smets, E.; Jansen, S.. |
| Recent studies on the functional significance of pit membranes in water conducting cells have renewed general interest in their micromorphology. At least two types of pit membrane thickenings have been described in angiosperm families, i.e. genuine tori and pseudo-tori. This study explores the distribution and morphology of pit membrane thickenings in 69 species and 23 genera within Oleaceae using light and electron microscopy. Torus-bearing pit membranes are confirmed for Osmanthus, and new records are reported for Chionanthus retusa, Picconia azorica, and P. excelsa, but not for the other species studied of Chionanthus. This infrageneric variation suggests that tori represent a plastic feature that has evolved more than once within the family as the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Electron microscopy; Pit aperture; Pit membrane; Plasmodesmata; Pseudo-torus; Torus; Tracheid; Vessel element; 42.56. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/429536 |
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| Lens, F.; Kårehed, J.; Baas, P.; Jansen, S.; Rabaey, D.; Huysmans, S.; Hamann, T.; Smets, E.. |
| Wood samples from 53 species belonging to 41 genera of the Icacinaceae s.l. are investigated using light and scanning electron microscopy. The traditionally circumscribed Icacinaceae fall apart into four segregate families that are clearly nested within asterids, i.e., Icacinaceae s.str. (near or in Garryales), Cardiopteridaceae and Stemonuraceae (both Aquifoliales), and Pennantiaceae (Apiales). From a wood anatomical point of view, these families cannot easily be distinguished from each other. However, some features such as vessel distribution, perforation plate morphology, size and arrangement of vessel pits, fibre wall thickness, and the occurrence of cambial variants can be used to assign various species to one of the four families. The wood structure... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Cambial variants; Comparative wood anatomy; Garryales; Icacinaceae; LM; Oncotheca; SEM; 42.58. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/424648 |
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| Lens, F.; Schönenberger, J.; Baas, P.; Jansen, S.; Smets, E.. |
| The systematic significance of wood anatomical characters within Ericales is evaluated using separate and combined parsimony analyses including 23 wood characters and 3945 informative molecular characters. Analyses of wood features alone result in poorly resolved and conflicting topologies. However, when pedomorphic character states are coded as inapplicable, the combined bootstrap topology results in an increase of resolution and support at most deeper nodes compared with the molecular analyses. This suggests that phylogenetic information from the limited number of morphological characters is not completely swamped by an overwhelming amount of molecular data. Based on the morphology of vessels and fibers, and the distribution of axial parenchyma, two... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Anatomy; Phylogeny; Ericales; 42.48. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/422235 |
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| Lens, F.; Jansen, S.; Robbrecht, E.; Smets, E.. |
| The Vanguerieae is a tribe consisting of about 500 species ordered in 27 genera. Although this tribe is mainly represented in Africa and Madagascar, Vanguerieae also occur in tropical Asia, Australia, and the isles of the Pacific Ocean. This study gives a detailed wood anatomical description of 34 species of 15 genera based on LM and SEM observations. The secondary xylem is homogeneous throughout the tribe and fits well into the Ixoroideae s.l. on the basis of fibre-tracheids and diffuse to diffuse-in-aggregates axial parenchyma. The Vanguerieae include numerous geofrutices that are characterised by massive woody branched or unbranched underground parts and slightly ramified unbranched aboveground twigs. The underground structures of geofrutices are not... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Vanguereae; Rubiaceae; Systematic wood anatomy; Geofrutex; 42.58. |
| Ano: 2000 |
URL: http://www.repository.naturalis.nl/record/423793 |
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| Registros recuperados: 26 | |
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