Lichens can be eaten as emergency or survival food, but they contain some harsh chemicals. So, to make them palatable, boil them at least once and throw the water away. The chartreuse-coloured wolf lichen that grows on trees or dead wood in dry country was used as wolf bait because it contains large amounts of the toxic vulpinic acid. It is best to avoid yellow and red-orange lichens due to high concentrations of toxic acids.

The photo shows some of the pale grey to yellow, shrubby, reindeer lichens. As the name suggests, they are eaten by “reindeer” or caribou. A special traditional meal for Inuit people is the warm stomach contents of a freshly killed caribou containing partly digested reindeer lichens.

Many lichens give wonderful dyes (browns and yellows) when boiled. Just put the cleaned lichens in a large pan with water and wool and boil them. Do it outside because they do give off choking odours.

Other lichens give off vivid red and purples after being fermented with ammonia in a dark glass bottle for a given time, strained, and then boiled with wool.

LAST WEEK: Overview of lichens

Some lichen dyes need a mordant and urine was commonly used. One dye extracted from a lichen known as “dyer’s weed’ is called litmus and is used as a pH indicator.

Some lichens are very sensitive to air pollution. The foliose Lungwort lichen is one of them. A fruticose lichen called Usnea is widely used to monitor air pollution. We have lots of both around here.

Years ago, we went to some mountains in the northern Czech Republic where all the exposed rocks looked greenish. This area was one of the most polluted parts of Europe and only the pollution-tolerant map lichen (Rhizocarpon geographicum) was able to survive there.

Lungwort lichen (Lobaria pulmonaria) got its name because it looks like human lung tissue. Large amounts were once gathered to make medicine for lung diseases.

Lichens containing cyanobacteria can fix nitrogen from the air and make it available to plants. They are particularly valuable in our moist conifer forests whose soils have low amounts of available nitrogen.

The lichen acids are strong and can break down rocks. In doing so, they release minerals into a primitive soil. The diameter of crustose lichens on rocks is often used to determine the age of the exposed rock.

editor@interior-news.com
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Lungwort lichen (Lobaria oregana) in Bulkley Valley. (Patrick Williston photo)