Lichens are complex life forms that are the result of a symbiotic partnership between multiple organisms, usually a fungus and an alga or cyanobacteria. Though often overlooked or mistaken for other organisms like moss, lichens are a critical part of each ecosystem they inhabit and are important sources of food, absorbers of carbon dioxide and biomonitors that help scientists detect air pollutants, among their many other functions.

The Secret World of Lichens is a beginner naturalist's guide to the wonderful world of lichens. Written in collaboration with the Canadian Museum of Nature by the Museum's chief lichenologist Troy McMullin, the book introduces the reader to lichens -- what they are, how they look and what they can do -- and then takes them on a survey of 40 of the most interesting and unique species of lichen in the world. Here are some of the curiously named lichens you'll find in these pages:

• Arctic Finger Lichen
• Blushing Rock Tripe
• Mealy Pixie Cup
• Devil's Matchstick
• Methuselah's Beard Lichen
• Green Specklebelly
• Toy Soldiers
• Wrinkled Shingle Lichen.

The Secret World of Lichens features stunning, full-page photos, detailed captions, fact boxes and a glossary of key lichen terms. This compact guide will make a wonderful gift for curious naturalists, young and old, who want to learn about the fascinating lives of these important organisms, and find them in the city, suburbs and countryside.

Troy McMullin is a research scientist in lichenology at the Canadian Museum of Nature and one of the foremost lichenologists in North America. He is currently the president of the Field Botanists of Ontario, an adjunct professor at Carleton University, a member of the Lichen Specialist Group for the IUCN and a research associate at Memorial University of Newfoundland. Troy has published extensively in both the academic and popular media spheres.

Troy McMullin's profile page

Informatively enhanced with the inclusion of full-page color photos, detailed captions, fact boxes and a glossary of key lichen terms. A compact and impressively organized and presented guide will have a very specially appeal to young naturalists wanting to learn about the fascinating lives of these important organisms, that exist in the city, suburbs and countryside... Highly recommended, especially for elementary school, middle school, and community library Botany and Biology collections.

Midwest Book Review

This well-researched guide will be a useful introduction for those curious about this fascinating life form, encouraging us to pay more attention to them. Thanks to its information, I've found what appears to be a Fruiting Honeycomb Lichen (Hypogymnia lophyrea) on the hawthorn tree in my yard! Highly Recommended.

Canadian Review of Materials

The Secret World of Lichens... Introduces readers to 40 of the most extraordinary species of the complex life form known as lichen.

Quill and Quire

Although often overlooked, lichens are a fascinating and important part of the ecosystems in which they live. Filled with beautiful, colour photographs of numerous species of lichens and complemented with interesting text by Dr. Troy McMullin, The Secret World of Lichens is a wonderful guide to these organisms... Along with detailed captions and interesting text, this book promotes learning by bolding some of the words in the text which are then defined in the glossary at the back of the book.

Toronto.com

A lichenologist shares both his enthusiasm and a more than superficial portion of what he knows about his favorite subject. Mushrooms may get most of the fungal love, but after poring over high-quality photos of 38 lichens and pausing to absorb McMullin's densely informative notes on their physical and reproductive structures, distribution, and manifold uses as food, medicine, dyestuffs, and even air pollution monitors, readers will be strongly tempted to divide their affections. A general introduction informs readers that these truly ancient symbiotic organisms, which combine a fungus and either algae or cyanobacteria (or, as the author puts it, "occasionally both!"), can be thousands of years old and grow up to "27 millimeters per year!" The book introduces close-up, in-your-cortex views of specimens with, often enough, memorable names like Fairy Puke Lichen, Blushing Rock Tripe Lichen, or Dead Man's Fingers. One type, Elegant Sunburst, survived more than a year and a half outside the International Space Station--but readers will have no trouble finding lichens of their own closer to home or, following the author's basic instructions, identifying and studying them. Glimpses of a minuscule new world for budding naturalists and a rare gap-filler for library collections, too.

Kirkus

Beautiful photographs and clear, well-written text.

Nature Book Guide

(starred review) This book introduces readers to lichens and showcases 38 of the most interesting and unique lichen species.

The Canadian Children's Book Centre's Best Books for Kids and Teens 2023

Beautiful photographs and clear, well-written text.

Nature Book Guide

Thirty-eight species of the roughly 20,000 known worldwide are beautifully displayed and show a variety of both micro and macro lichens. He ends the book with a short glossary of terms which are linked throughout the text. As we naturalists know, understanding terms particular to a group of organisms is essential. Clearly not meant as a regional guide, this book introduces the great variety of colors and growth forms found in this part of the fungal kingdom along with other tidbits like geography and substrate... I enjoyed reading it with my six-year-old... I will be passing this book on to my niece and nephew... And buying more copies to donate to our public and school libraries. McMullin has provided a doorway to appreciation and awareness for lichens which will surely instill greater concern for our natural world.

Northwest Lichenologists