hat 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.