This volume - the first of this series dealing with angiosperms - comprises the treatments of 73 families, representing three major blocks of the dicotyledons: magnoliids, centrosperms, and hamamelids. These blocks are generally recognized as subclasses in modern textbooks and works of reference. We consider them a convenient means for structuring the hundreds of di cotyledon families, but are far from taking them at face value for biological, let alone mono phyletic entities. Angiosperm taxa above the rank of family are little consolidated, as is easily seen when comparing various modern classifications. Genera and families, in contrast, are comparatively stable units -and they are important in practical terms. The genus is the taxon most frequently recognized as a distinct entity even by the layman, and generic names provide the key to all in formation available about plants. The family is, as a rule, homogeneous enough to conve niently summarize biological information, yet comprehensive enough to avoid excessive re dundance. The emphasis in this series is, therefore, primarily on families and genera.

"There is nothing in the world like this book. It should be in every library and on the bookshelves of all those interested in cacti. The book will be an important resource for plant physiology, agronomy, and horticulture classes at both the undergraduate and graduate level."—Bruce Smith, Brigham Young University "Cacti: Biology and Uses is a landmark publication of one of the world's most unique group of plants. Park Nobel, a leading authority on succulent plants, has assembled a collection of contributions that spans a wide range of issues extending from basic systematics, anatomy, physiology and ecology to considerations of conservation and human uses of this diverse group of plants. This nicely-produced and well-illustrated volume provides a resource that will be of great use to a wide range of scientists, practitioners, and enthusiasts of this plant group."—Harold Mooney, Paul S. Achilles Professor of Environmental Biology, Stanford University

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