This volume contains reviews presented at the 31 st annual meeting of the Phytochemical Society of North America, held at Colorado State University in Fort Collins, Colorado on June 22-26, 1991. This symposium, entitled Phenolic Metabolism in Plants, celebrated the origin of this society as the Plant Phenolics Group of North America; the first symposium, entitled Biochemistry of Plant Phenolic Substances, was also held at Fort Collins from August 31 to September 1, 1961. A brief history of the Society is presented in Chapter 12 by Stewart Brown, one of the original founders of the Society. We dedicate this volume to Hans Grisebach, 1926-1990, Professor of Biochemistry at the Biologisches Institut II, Freiburg, Germany, where he headed for many years a laboratory responsible for major advances in the area of phenolic metabolism; this will be self evident from the numerous bibliographical references cited in the literature for papers by his Freiburg group from about 1958 until now, and subsequently by former students and colla­ borators. His impact on the data reviewed in this volume will testify to this.