Amy Stewart is the author of “The Drunken Botanist: The Plants that Create the World’s Great Drinks” and a new novel, “Girl Waits with Gun.”

Do plants have agendas of their own? Do they act with agency, as animals and humans do, or are they passive bystanders? If our planet is a theater, are plants the actors or the props?

British writer Richard Mabey, author of “Weeds,” “Flora Brittanica” and many other books on the natural world, proposes to answer this question in his new book, “Cabaret of Plants.” Given the title, you can probably guess where his allegiances lie. Plants, he argues, are entirely capable of setting their own agendas, and they do it with little concern for us.

From the very beginning, Mabey gets at one of the most vexing problems any writer has when writing about plants: They’re not interested in us. They don’t do what they do to entertain us. They act, in many cases, as if we don’t exist at all. To them, we probably don’t. Imagine: There are creatures living on our planet, right now, who have never heard of us. And they’re not hiding in some remote jungle. They’re in our back yards and even inside our homes. It might be a little humbling to realize that your ficus tree knows nothing about you or your kind, but it’s true. Plants are busy, and they don’t care about our needs, even as they satisfy them.

‘The Cabaret of Plants: Forty Thousand Years of Plant Life and the Human Imagination’ by Richard Mabey (W. W. Norton)

One of the funniest and most refreshingly honest moments comes early in the book, in a chapter on yew trees. Mabey goes to visit the Fortingall Yew, an ancient tree that might well be the oldest living creature on the planet, with an estimated age of 5,000 years. It is surrounded by a fence to protect it from collectors, who once hacked so many pieces from the trunk that it split in the center, leaving a gap “wide enough to carry a coffin through.”

As he stood before this ancient tree, Mabey explains, “what unnerved me was how dull I was finding the Great Yew.” The tree was surprisingly short — not much larger than a hedgerow — and was utterly lacking in “panache and power and narrative fascination.” He immediately realized how presumptuous it was to expect to be entertained by a tree. A tree is not at all concerned with its appearance, nor should it be, except for the fact that a magnificent specimen might be deemed more worthy of preservation — or more vulnerable to souvenir hunters.

In spite of this episode, Mabey goes on to organize the book according to the many ways plants have, in fact, fascinated us throughout history. He begins with a chapter on the scarcity of plant depictions in Paleolithic art, then skips ahead to a remembrance of the years he spent traveling with photographer Tony Evans, who thought nothing of sitting before a flower for 24 hours, waiting for it to bloom. From there he spends several chapters meditating on the longevity and adaptability of trees, then devotes five chapters to plant-related myths, such as the so-called vegetable lamb, a half-animal, half-plant described by several writers in the Middle Ages. After that he examines the ways plants have inspired artists, writers and scientists in other fields, then takes a turn through the history of Victorian plant collecting.

If all of this sounds like a bit of a hodgepodge, that’s because it is. If you’re someone who thinks deeply and frequently about plants, much of this botanical history will be familiar. It’s amusing to read about how Linnaeus described plant sex, shocking his peers by depicting a flower’s stamens and stigmas as “nine men in the same bride’s chamber, with one woman,” and it’s interesting and a little horrifying to realize that terrariums and greenhouses were invented after an 18th-century scientist discovered that a mouse could survive under glass if a plant was also kept inside to revive the air. But I’m not sure that stories like these advance Mabey’s cause, other than to demonstrate that people are fascinated with plants and will do strange and sometimes odd things in their presence.

At the end of the book, in a chapter on plant intelligence, Mabey looks ahead to new science that points to ways plants might have more autonomy and agency than we ever could have guessed. An ecologist named Monica Gagliano, for example, conducted a series of experiments with mimosa plants in 2013. The leaves snap shut anytime they’re touched, earning the plant the name “sensitive plant.” Gagliano tested this by dropping potted plants from a height of six inches and observing that they slammed their leaves shut as a defensive mechanism. But after being dropped several times, some of them stopped bothering to close their leaves. After related experiments, it appeared that the plants had learned that certain movements were not a threat after all and were capable of remembering this information even a month later. This comes as a powerful shock to those of us who thought that plants can’t think.

Other ecologists have shown that the fungi that colonize tree roots are capable of moving nutrients around an underground network made up of many different species that work together to direct food to the seedlings that need it the most. Are trees collaborating? Another recent experiment demonstrates that bean vines can grow deliberately in the direction of a pole, rather than casting aimlessly about as had been believed. It’s possible that the plants are generating some sort of clicking sound and using echolocation to find their targets. Are beans listening?

This new research suggests that plants might have lives beyond our current understanding. Perhaps they are capable of taking deliberate action, just as animals do. It’s a shame that this topic occupies only the last 10 pages of Mabey’s book, because it does more to prove his point than everything that came before, however interesting and entertaining it might have been.

The Cabaret of Plants
Forty Thousand Years of Plant Life and Human Imagination

By Richard Mabey

Norton. 374 pp. $29.95