Book Review – ‘What A Plant Knows’ by Daniel Chamovitz

Humans use their senses to get information about the world around them. We use this information, in part, to decide what actions to take. Our five main senses are sight, smell, hearing, taste, and touch. Do plants have similar senses?

In What A Plant Knows, Israeli botanist Daniel Chamovitz compares human senses with equivalent senses in plants. In each chapter, he describes a human sense, then explains whether plants have a similar ability to perceive the world around them. Plants do have senses similar to humans with one exception (hearing), because plants also need to gather information from the world and then act on this information.

For example, plants can “see,” i.e. perceive light, as we can tell when plants grow towards a light source. It is vital that plants perceive light because, for plants, light equals food. For each sense, the author explains how the sense is exhibited in a plant and also the historical development of our understanding of the ability, including clear, brief descriptions of elegant experiments. For example, for the perception of light with concurrent growth towards the light source (phototropism), Darwin hypothesized that light was perceived at the tip of a seedling so he performed the following test: one shoot was allowed to grow normally, bending toward the light; the next had the tip cut off and did not bend; the third had a dark cap on the tip and did not bend; the fourth had a glass cap on the tip and did bend; and the fifth had a band around the stem and not the tip and did bend toward the light.

In addition to the five human senses, there are chapters on how plants know where they are in space (perception of gravity) and what and how a plant remembers.

This fascinating book is so readable it’s like reading a novel or a mystery—you get caught up in wanting to know the answers and find it hard to put down. When you’ve finished this little book, you’ll have a better understanding of how plants live, function and perceive their environment, and you will also probably treat plants with more respect and appreciation for their abilities. You will find that you have more in common with plants than you might previously have thought and you will appreciate the interconnectedness of all living things. Having a better understanding of plants and how they live may also result in better care of the plants in our gardens and landscapes, as we understand their needs better.

Submitted by Ann Guthals