Green plants dominate our planet yet are often taken for granted. For many people, they are merely the passive aspect of a beautiful landscape, the “backdrop” against which animals exist. For others, they are essential to their lives but are there simply to be exploited for food, fodder, fuel, furniture, clothing, transport, recreation, health purposes, and protection without thought being given to their unique qualities as living things in their own right.

In the first four Parts of this edition, I have attempted to provide some insights into the very different world of green plants. Their lives are lived at a different pace from ours, which may be one reason why we so often forget that they are living organisms capable of doing so many of the things we also do. Like us, but in their own way, they can see, they can count, they can communicate with one another, they can be sensitive to the slightest touch and they can tell time with considerable precision. But they accomplish all of these things on a different timescale from most animals. Their very slowness deceives us into believing that they do not do much at all.

We should not forget, however, that green plants are unique among all organisms on Earth in that they alone have the means to use light as a source of energy. The very substance which renders them green, the pigment chlorophyll, puts them in the position of being the very foundation of our biosphere.