The systematic wood anatomy of the Moraceae (Urticales) IV. Genera of the tribe Moreae with urticaceous stamens

The wood anatomy of the genera of the tribe Moreae with urticaceous stamens, viz. Broussonetia, Madura s.l. (including Cardiogyne, Chlorophora, and Cudrania), Malaisia, Milicia, Morus, Olmedia, Pachytrophe, Plecospermum, Sloetiopsis, Streblus s.l. (including Paratrophis, Phyllochlamys, Pseudostreblus, and Sloetia), and Trophis s.l.(including Calpidochlamys and Maillardia), is described in detail. Separate descriptions have been made for sections and/or subgenera to facilitate the discussion about the generic delimitations made by several taxonomists. The following generic combinations previously proposed by taxonomists are supported by wood anatomical features: Broussonetia + Allaeanthus: Maclura + Chlorophora + Cardiogyne + Cudrania + Plecospermum. The segregation of the African species of Chlorophora in a separate genus Milicia is supported by wood anatomical evidence. The broad genus concept of Streblus and Trophis is not supported by wood anatomy. Several sections of these genera should be reinstated as genera. The correlations between wood anatomy, latitude, habit and habitat are discussed as far as allowed by the material studied. Characters useful for the delimitation of the genera proved to be the size of the intervascular pits, the parenchyma distribution, and the lengths of fibres and vessel elements. Rhombic crystals, vitreous silica and radial latex tubes usually are useful additional characters.