The wood anatomy of 127 samples of 65 species of all 18 genera of the Rhizophoraceae is described in detail; features not observed here, but recorded in the literature are added. Wood anatomically several groups can be recognized. Three distinct groups are very homogeneous, coinciding with the Rhizophoreae ( Bruguiera, Ceriops, Kandelia, and Rhizophora), the Anisophylleae ( Anisophyllea, Combretocarpus, Poga, and Polygonathus), and the Macarisieae ( Anopyxis, Blepharistemma, Cassipourea, Comiphyton, Macarisia, and Sterigmapetalum), as recognized by several taxonomists. One group, the Gynotrocheae (Carallia, Crossostylis, Gynotroches, and Pellacalyx), is rather heterogeneous. The family as a whole is wood anatomically very heterogeneous, but this diversity can be interpreted as the result of divergent xylem specialisation in the different groups. Although the woods of the mangrove genera (Rhizophoreae) are very different from all inland representatives of the family, there are no arguments to regard their character complex as a special adaptation to an unusual environment. Other ecological considerations are also discussed. A key to the woods is presented. Most of the genera can easily be identified, using xylem characters only. Some are, however, difficult to separate wood anatomically.