Throughout the year I collect new books and there is never enough time to dig into them during the summer and fall. In winter I savor the time to compare my photos with my field guides and investigate questions I haven’t yet answered.
My favorite new field guide is “Lichens of the North Woods” by Joe Walewski, a handy, small field guide to 111 northern lichens. Although the author is from Finland, Minn., and the book’s primary area is the Great Lakes region, the lichen species included are nearly all found in the Adirondacks.
Lichens make up for their obscurity with names like Candleflame, Tree Jelly, Methuselah’s Beard, Crumpled Rag and Yellow Specklebelly. This book prompted me to start training my eyes to notice more lichens and where they grow.
Lichens are not single organisms — they are a partnership of a fungus and an alga or cyanobacteria. Although the fungus and the alga or cyanobacteria might exist by itself in nature, many have become completely dependent on each other and do not exist as independent individuals. The University of California Museum of Paleontology refers to lichen as “an alliance between kingdoms.”
In the partnership the alga has the ability to make food through photosynthesis and the fungus provides the protection of structure and shade. Lichens spread when small pieces break off — each piece contains both parts of the organism. Although they can begin growing right away lichens grow extremely slowly. They have a remarkable ability to withstand extremes of drought and temperature and resume growth.
Lichens grow on the ground, on rocks and on trees. Some species grow on more than one substrate, but generally the first step of lichen identification is to note the substrate. Texture, moisture retention and chemistry determine which lichens favor which surfaces.
The second step of identification is to determine a lichen’s shape. Most are one of three basic shapes: crustose, fruticose or foliose. Walewski keeps the explanations of each shape simple: “Crustose lichens look like spray paint”; “Foliose lichens look like leafy growths divided by lobes”; and “Fruticose lichens are literally bushy or shrubby growths.”
“Lichens of the North Woods” is full of excellent photographs, and lichens are surprisingly colorful. Oranges, yellows and reds can all be found but grays, olive-browns and blue-greens also make mosaics on surfaces throughout the forest.
Different forest communities support different arrays of lichens. Young maple trees may be colonized by certain lichens that prefer hard, smooth substrate while older maples host lichens that take advantage of the softer, more cracked bark.
As with all living things, lichens play a part in forest food webs. White-tailed deer, moose, squirrels and some insects eat lichen. Songbirds weave nests from long strands of beard lichen. Hummingbirds camouflage their nests with shield lichen and frogs and insects use lichen for camouflage.
Like mosses and ferns, lichens seem foreign and complex to learn but most people know many by sight.
“Lichens of the North Woods” is a simple, lightweight, well-organized reference that will tuck easily into a pocket or day pack for those who want to learn the names of common lichen, either by the wood stove this winter or on rocky summits next summer.
Warm wishes to all and a Happy New Year with many good adventures.
Elizabeth Lee is a licensed guide who lives in Westport. She leads recreational and educational programs focused in the Champlain Valley throughout the year. Contact her at email@example.com.