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| Registros recuperados: 26 | |
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| 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 |
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| Lens, F.; Sperry, J.S.; Christmas, M.A.; Rabaey, D.; Jansen, S.. |
| • Vulnerability to cavitation and conductive efficiency depend on xylem anatomy. We tested a large range of structure–function hypotheses, some for the first time, within a single genus to minimize phylogenetic ‘noise’ and maximize detection of functionally relevant variation. • This integrative study combined in-depth anatomical observations using light, scanning and transmission electron microscopy of seven Acer taxa, and compared these observations with empirical measures of xylem hydraulics. • Our results reveal a 2 MPa range in species’ mean cavitation pressure (MCP). MCP was strongly correlated with intervessel pit structure (membrane thickness and porosity, chamber depth), weakly correlated with pit number per vessel, and not related to pit area... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Acer; Cavitation resistance; Hydraulic conductivity; Pit structure; Rare pit hypothesis; Vessel distribution; Vessel wall thickenings; Wood density; 42.56. |
| Ano: 2011 |
URL: http://www.repository.naturalis.nl/record/429474 |
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| 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 |
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| 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 |
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| 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 |
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| Registros recuperados: 26 | |
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