MTPR

lichen

Wolf Moss: Wallpaper Of The World's Forests

Oct 30, 2017
Wolf Moss
Claire Burgeson

Although small and unobtrusive, an estimated 13,000 to 17,000 species of lichen spread across the Earth, from the Arctic to the equatorial tropics. One of those species, more noticeable than most, is Letharia vulpina, a brilliant fluorescent yellow-green, moss-like lichen that clings to the bark and wood of living and dead trees throughout the world, from sea level to timberline.

Flickr user, Jason Hollinger (CC-BY-2.0)

Recently, the work of lichenologist Toby Spribille, a research professor based part-year at the University of Montana-Missoula, has upended the idea that lichen are an alliance between just one fungus and one algae. In many lichens, a mysterious yeast is the third player in this symbiosis. 

Flickr user, Kirill Ignatyev

You might have brushed by it in the forest, where this hairy-looking symbiosis between algea and fungi perches on tree limbs. The look of the lichen usnea explains its nicknames: "old man's beard," "tree's dandruff," "women's long hair," and "beard lichen." For centuries, it's been considered a handy medicinal. People grab some to dress wounds, or take it internally for infections or oral inflammation. But in the 1990s, when manufacturers of weight-loss drugs started adding sodium usniate (usnic acid) to their formulas, several cases of liver damage emerged.