For more than 100 years, leaf venation patterns have been considered diagnostic for plants and are thought to reflect plant evolution. Furthermore, venation patterns are considered valuable for taxonomic purposes as well as a criterion for studying phylogenetic developments. The present volume 9 deals with the venation patterns of the subfamilies Acalyphoidea, Crotonoidea and Euphorbioidea of the Euphorbiaceae. Leaves of 135 genera from these three subfamilies were cleared and and examined.

The descriptions of venation patterns follows the format used in previous volumes: After the generic name, a short phrase indicates the number of species attributed to the genus, its geographical distribution followed by the nubmer of leaf species collected for the particular genus. The venation patterns observed within the genus are then described with citations of the species used for clearing and description. The descriptions are supplemented by plates showing diagnostic leafs and their venation patterns on 187 high quality plates.

This new volume of Klucking's series on leaf venation patterns discusses the second part of the family Euphorbiaceae including the subfamilies Acalyphoideae, Crotonoideae and Euphorbioideae. In total the venation patterns of 191 genera are described in Klucking's own system. Most genera have palmate or pinnate or intermediate venation patterns. A brief discussion of the distribution of these patterns over the family closes off the text part of this volume. A huge selection of photographs of cleared leaves, 187 plates with in the average 6 photographs per plate forms the main part of the book.

The main importance of the series on leaf venation patterns lies in the use of cleared leaves as a tool to identify fossil leaves. Floristic systematists working on present day floras often use different systems for describing leaf venation.

FRITS ADEMA

Blumea vol. 48, no. 3, 2003