Personal treatises on animals and plants have a centuries-old tradition. Among the well-known names of the genre, which is in great demand today, is the Italian biologist Stefano Mancuso. He has now published another book in a whole series of titles with a botanical focus, after he recently dealt rather superficially with the rights of plants. For "The World of Plants", Mancuso chooses a more modest form. In nine chapters, he presents special aspects of plants, sometimes interwoven with personal observations and experiences. Fortunately, he refrains from rehashing overly striking theses about an "intelligence" of plants, as he did in earlier books.

In his introduction, Mancuso thinks he has to justify his interest in plants. He wonders if he is as blinded as a lover because he sees only plants everywhere, but then comes to the conclusion that there is no other way on a planet whose inhabitants are mostly plants.

Like in microscopic organ pipes

However, the individual chapters do not add up to a plea or an overarching message. Rather, they are self-contained botanical excursions – for example, to a special class of trees planted in France to commemorate the French Revolution and in the USA to commemorate the struggle for independence. Mancuso describes these trees, which exist only for political reasons, as a widely scattered "brotherhood". In doing so, he takes up a subject from earlier books, which dealt with the connections and networks between plants that are invisible to the human eye. The fact that this should now also apply to trees planted with the same intention seems quite exaggerated.

Some of the observations are somewhat stilted and abstract, for example when it comes to the plant world in the cities. Here the author could actually go all out and draw on his botanical practice. He could present plant species that defy the adverse conditions of large metropolises, he could explain why it is important to create urban trees and networked green spaces – so that cities remain habitable at all in the heat waves of the future. Instead, he mainly offers architectural history that has little to do with the matter and looks as if he had copied it from a research dossier into the manuscript.

Plants are important for all sorts of things

Such weak chapters can be skipped without damage and focus on the profitable parts of the book. This includes the exploration of the trees used in instrument making, a topic on which Mancuso has researched. According to the description, the perfect sound conduction of violins is due to tiny resin channels that remain hollow when stored correctly, "so that the air in them can vibrate like in microscopic organ pipes". Another decisive factor for the sound is how the resin crystallizes on the walls of these channels.

It is from such insights that the book draws its strength. It is also impressive how Mancuso reconstructs the history of timekeeping with the help of tree rings. He not only brings to light the anecdote of how a researcher felled what is perhaps the oldest tree in the world without any need for sampling, but also traces how the method of determining the age based on annual rings was initially ridiculed. Even for the purely physical method of using carbon isotopes to measure age, the tree data is needed for calibration. Plants are important for all sorts of things, that's the message.

After rather humorous remarks on his research on how slippery banana peels really are, Mancuso devotes the last chapter to another secret "brotherhood" of trees. It's about the plants whose seeds astronaut Stuart Roosa took with him on a moon mission in 1971 and had them orbit the Earth's satellite 34 times in his luggage. After their return, the seeds were first planted in the USA, but then also worldwide as "moon trees". The "Nature Writing" – to which Mancuso makes an entertaining contribution with "The World of Plants" – thus includes the moon.

It remains to be seen whether the moon trees and other plants from the book "make history", as the subtitle promises. Wheat plants, for example, are more likely to do this if there are not enough of them and entire regions of the world are thrown into chaos. But it's also enough for plants to offer exciting stories.

Stefano Mancuso: "The World of Plants". And how they make history. Klett-Cotta Verlag, Munich 2023. 192 p., ill., born, 25,– €.