In this volume, 24 flowering plant families comprising a total of 911 genera are treated. They represent the asterid order Lamiales except for Acanthaceae (including Avicenniaceae), which will be included in a later volume. Although most of the constituent families of the order have been recognized as being closely related long ago, the inclusion of the families Byblidaceae, Carlemanniaceae and Plocospermataceae is the result mainly of recent molecular systematic research. Keys for the identification of all genera are provided, and likely phylogenetic relationships are discussed extensively. To facilitate the recognition of relationships, families are cross-referenced where necessary. The wealth of information contained in this volume makes it an indispensable source for anybody in the fields of pure and applied plant sciences.