The results, published in this book, present the outcome of a cooperative research between plant ecologists, physiologists and population geneticists. The project received generous financial support from the Foundation for Bio logical Research, which is subsidized by the Netherlands Organization for Scientific Research. During the course of the Project the value of the in tegrative approach on a limited number of Plantago species and populations became evident and it was decided that the results should be published as a book. The start of the preparation of the "plantago" book was done by Dr. P. J. M. van der Aart and Dr. H. Lambers but due to their appointment as full professor of the University of Utrecht they were both unable to continue. We are greatly indebted to Van der Aart and Lambers for the groundwork they have laid. The book presents a sample of results obtained over a period of more than 10 years. Research on Plantago is still continuing, as evident from a number of publications and doctoral theses. We want to thank the authors for their pa tience and assistance to complete the job. The editorial assistance of Mrs. I. Cameron-Doornbos was extremely valuable, as well as the help of Mr. E. Leeuwinga und Mrs. N. Tolmeijer with the drawings and the help of Mrs. T. E. Stuit with the list of references.