This book intends (according to the preface) to afford at once a review, a general outline of what has been accomplished, and a set of signposts for the future. It attempts to do so in three sections on Origin and Diversification of Primitive Land Plants (4 papers), Origin and Diversification of Angiosperms (6 papers), and Speciation and Mechanisms of Diversification (5 papers). In a sense our discipline is in a state of change that could be called revolutionary, rapidly acquiring new facts. In this situation the need is felt for a survey of what has been accomplished and what the future may bring. This slim volume serves as a prime example of an attempt to do so. It covers phylogenetic fields: early land plants, Pteridophytes, conifer fami...