Wood anatomy of the Euphorbiaceae, in particular of the subfamily Phyllanthoideae

The great variety in wood structure of the large family Euphorbiaceae makes it impossible to describe briefly a general wood pattern. Nevertheless, a more or less clear division into four anatomical groups can be made. A short overview is given of the wood structure of the uni-ovulate subfamilies Acalyphoideae, Crotonoideae, and Euphorbioideae, following the classification by Webster. These subfamilies cannot be distinguished by their anatomy. The paper is mainly devoted to the bi-ovulate subfamily Phyllanthoideae. Within this subfamily, two groups can be recognized on the basis of their wood anatomy: the Aporusa type with a great number of primitive characters, and the Glochidion type, in which primitive features such as scalariform vessel perforation plates are absent. A short description of the 13 tribes is given as well as suggestions for rearrangement of the succession of the tribes. In several tribes some taxa are anomalous and, on anatomical evidence, exclusion of some genera, sometimes with assignment to another tribe, is suggested.