The Evolution of Ericales: Recent Insights using both Morphology and Molecules
Lens, Frederic , Baas, P. , Jansen, Steven , Smets, Erik .
The usefulness of systematic wood anatomy in Ericales. A case study in Lecythidaceae s.l..
WOOD samples of 78 species representing 24 genera of Lecythidaceae s.l., including Napoleonaeoideae and Scytopetaloideae, were investigated using LM and SEM observations. The family is characterized by solitary vessels and vessels in radial multiples, predominantly simple vessel perforations, alternate intervessel pitting, fibres with simple to minutely bordered pits, diffuse-in-aggregates to banded axial parenchyma, and the presence of prismatic crystals in axial parenchyma. Our observations indicate that the secondary xylem possesses phylogenetically useful characters at the subfamily level. Napoleonaeoideae are distinctive due to a combination of characters, such as the occurrence of mixed simple and scalariform vessel perforations, scalariform vessel-ray pitting, and high multiseriate rays. Scytopetaloideae closely resemble Napoleonaeoideae in their wood structure, corroborating a close relationship as has been established by molecular data. In addition, uniseriate rays are common in both subfamilies, but scarce in the other taxa. The isolated position of Foetidia (Foetidioideae) can be supported by vessel-ray pitting with distinctly bordered pits, small intervessel pits (10 µm), two distinct types of vessel-ray pitting, both procumbent and square body ray cells in multiseriate rays, and prismatic crystals in non-chambered axial parenchyma cells without pronounced wall thickenings. The largest subfamily Lecythidoideae can be identified by intervessel pits of 6-9 µm in size, two types of vessel-ray pitting, short and narrow multiseriate rays, prismatic crystals in chambered axial parenchyma cells with unilaterally thickened walls, and silica grains in ray cells. Most of these features point to a relationship with Planchonioideae. -DU
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1 - Institute of Botany and Microbiology, Department of Botany, Laboratory of Plant Systematics, Kasteelpark Arenberg 31, Leuven, BE-3001, Belgium
2 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Richmond, Surrey, TW9 3DS, United Kingdom
3 - National Herbarium of the Netherlands, Leiden University branch, P.O.Box 9514, Leiden, NL-2300 RA, Netherlands
Presentation Type: Symposium or Colloquium Presentation
Date: Monday, July 31st, 2006
Time: 1:30 PM