ALBERT

Description: The wood anatomy of 47 genera of the neotropical Melastomataceae is described in detail. The wood anatomy of the neotropical part of this pantropical family supports the subdivision into two groups: the subfamily Memecyloideae (the genus Mouriri) and the subfamily Melastomatoideae (all other genera). A relationship of Mouriri with other representatives of the family is not supported by the wood anatomical characters, because of differences in fibre type, vessel distribution, and the fibre length/vessel member length ratio, and the presence of included phloem in Mouriri. The subfamily Melastomatoideae is a fairly homogeneous group. Although some characters are very pronounced in some tribes and scarce or absent in other tribes, most tribes show a wide overlap in their wood anatomical features. An important means to distinguish to a certain extent between tribes is the size and shape of the intervascular pits combined with the size and shape of the vessel—ray and vessel—parenchyma pits. Three groups can be recognized: type 1. all pits round to slightly oval; type 2. intervascular pits round to oval, and the vessel—ray and vessel—parenchyma pits more elongated, oblong to scalariform; type 3. all pits round to oblong and scalariform. Other diagnostic characters are the parenchyma distribution, and the distribution of the fibre pits. The tribe Blakeeae can be separated from the other tribes due to the presence of druses and 2-4-seriate rays. The relationship between wood anatomical characters and habit and habitat, as well as possible phylogenetic trends in the family and classification of the neotropical tribes are discussed.

Description: Cystoliths were observed in the secondary xylem of Sparattanthelium (Hernandiaceae). Their shape, size, distribution and chemical composition is described. The systematic value of cystoliths in the Hernandiaceae as well as in general is discussed.

Description: Cystoliths were observed in the secondary xylem of Sparattanthelium (Hernandiaceae). Their shape, size, distribution and chemical composition is described. The systematic value of cystoliths in the Hernandiaceae as well as in general is discussed.

Description: The wood anatomy of 47 genera of the neotropical Melastomataceae is described in detail. The wood anatomy of the neotropical part of this pantropical family supports the subdivision into two groups: the subfamily Memecyloideae (the genus Mouriri) and the subfamily Melastomatoideae (all other genera). A relationship of Mouriri with other representatives of the family is not supported by the wood anatomical characters, because of differences in fibre type, vessel distribution, and the fibre length/vessel member length ratio, and the presence of included phloem in Mouriri. The subfamily Melastomatoideae is a fairly homogeneous group. Although some characters are very pronounced in some tribes and scarce or absent in other tribes, most tribes show a wide overlap in their wood anatomical features. An important means to distinguish to a certain extent between tribes is the size and shape of the intervascular pits combined with the size and shape of the vessel\xe2\x80\x94ray and vessel\xe2\x80\x94parenchyma pits. Three groups can be recognized: type 1. all pits round to slightly oval; type 2. intervascular pits round to oval, and the vessel\xe2\x80\x94ray and vessel\xe2\x80\x94parenchyma pits more elongated, oblong to scalariform; type 3. all pits round to oblong and scalariform. Other diagnostic characters are the parenchyma distribution, and the distribution of the fibre pits. The tribe Blakeeae can be separated from the other tribes due to the presence of druses and 2-4-seriate rays. The relationship between wood anatomical characters and habit and habitat, as well as possible phylogenetic trends in the family and classification of the neotropical tribes are discussed.