The Secret World of Lichens - A Review

The Secret World of Lichens

 

Written by Troy McMullin

Cover and interior design: Gareth Lind

Published by Firefly Books Ltd. (2022)

 

Fairy Puke Lichen. Yes, that’s right. I could’ve started with Christmas Lichen or Devil’s Matchstick Lichen, of course, or the fantastically-named Blushing Rock Tripe Lichen. Or maybe Dead Man’s Fingers does it for you? Well, they’re all here in this wonderful introduction to lichens by Troy McMullin, the Canadian Museum of Nature’s Head of Botany and chief lichenologist. Enlivened by stunning photography, this is a book that encourages young naturalists to ‘look closely’ in their local environment for these wonderful organisms and to discover a secret world of bright colours, interesting shapes and super fun names! 

The book opens with McMullin explaining what lichens are, what they look like and how they reproduce. The detail is considerable, but it is given context by a series of photographs of the three main types of lichen – crustose, foliose and fruticose – and a diagram that shows an example structure of a typical foliose lichen. A particularly pleasing aspect here is that the author highlights how some lichens can look very different when wet compared to when they are dry. It’s an important thing to know, especially when learning to identify lichens in the field. McMullin moves on to discuss lichen growth, age, fossils and their use as food, in medicines, dyes and pollution monitoring. Of particular interest to young people will be the revelation that a Yellow Map Lichen of the Arctic is one of the oldest living things on Earth at 8,600 years old, as well as the discussion of camouflage and how some smaller creatures such as caterpillars use lichens to hide from predators. The Ilia Underwing moth caterpillar in the US, for example, is able to blend in with many common lichens such as Tube Lichens and Shield Lichens. Also, some birds lay eggs that have a similar colour and pattern to the lichens in their nests.

The main part of the book is taken up by 38 high-quality, full-page lichen photographs, detailed captions and fact boxes describing the lichens present, all of which are located somewhere between the Arctic and the tropics. Among them, a wide range of rock, soil, tree and artificial surface lichens can be found. Many of the ones chosen are visually attractive, some are rare, and some are more well-known such as Usnea. By using their common names, alongside their scientific ones, McMullin adds a further layer of fun and wonder that will certainly help younger readers both engage with the text and remember what they’ve discovered. Readers are advised where to look for the lichens and are encouraged not to collect or remove them from their environment, but instead to take a photograph and write down where they were growing, on what surface and on what date. This information can then be used to help identify the lichens and can also be entered into databases such as inaturalist.org as part of the Citizen Science movement to aid with the collection of data and mapping of changes in ecosystems and habitats in relation to climate change, for example. 

In summary, this is a book that celebrates the beauty of lichens and invites us into their fascinating universe. Aimed at KS3 and above, I strongly feel that children in KS2 could also access and be inspired by it. In line with this, the glossary at the end of the book will further demystify some of the more challenging terminology for those younger readers. My only criticism is that it would have been good to see a list of further resources that would direct readers to books or places on the internet where they can learn more, especially with regards to identification techniques. Lichens are hugely important for the reasons outlined in this review, as well as for ecosystem hydrology and carbon and nitrogen cycling. However, they suffer a public understanding and engagement issue. One of the difficulties is that lichens don’t fit neatly into school curriculums, especially lower down, because they are complex and too dissimilar to the common plants that are usually studied in units such as ‘Living Things and their Habitats’, for example. Books like this that are aimed at a younger audience help raise the profile of lichens and lichenology, and I would encourage both KS2 and KS3 teachers to include The Secret World of Lichens in their book corners and libraries. As McMullin says: ‘Once you get an eye for lichens, you will start seeing them everywhere. That is when you know their secret world has been revealed!’