Green Plants is a thoroughly revised edition of the earlier Diversity of Green Plants by P. R. Bell and C. L. F. Woodcock (3rd edition, London, 1983). The continuing demand for a concise account of the algae and land plants from the point of view of their natural relationships and biology reflects the buoyant state of botanical science. Exciting advances remain a feature of all its aspects. The biophysically minded are revealing in impressive detail the electron pathways in the thylakoid membrane while paleobotanists expand significantly our knowledge of the earliest angiosperms of the Cretaceous and geneticists explore the molecular aspects of plant development. The theme of Green Plants is the astonishing diversity of forms which evolution has provided from the atmospheric carbon fixed by photosynthesis, the remarkable phenomenon which is basic to plant life. The treatment of the Plant Kingdom correspondingly extends from the simplest cellular organisms capable of phototrophy, the prokaryotic algae, to the complexities of the flowering plants, not omitting (so far as they are known) the essential features of the plants represented only by fossils.

The record of plant life provides a striking instance of both genetic conservation and variation. The photochemistry of the thylakoid membrane is presumably basically the same today as it was at the dawn of plant life in pre-Cambrian times, and the genetical system controlling its development likewise essentially unchanged.