Colourful Beauties of Stockholm: Lichens

Colonies of lichens may be spectacular in appearance, dominating the surface of the visual landscape as part of the aesthetic appeal to paying visitors of Stockholm. Orange and yellow lichens add to the ambience of trees, rock faces, tundras, and rocky seashores. Intricate webs of lichens hanging from tree branches add a mysterious aspect to forests.

In the past, Iceland moss was an important source of food for humans in northern Europe and was cooked as bread, porridge, pudding, soup, or salad. Wila (Bryoria fremontii) was an important food in parts of North America, where it was usually pit-cooked. Northern peoples in North America and Siberia traditionally eat the partially digested reindeer lichen (Cladina spp.) after they remove it from the rumen of caribou or reindeer that have been killed. Rock tripe (Umbilicaria spp. and Lasalia spp.) is a lichen that has frequently been used as an emergency food in North America, and one species, Umbilicaria esculenta, is used in a variety of traditional Korean and Japanese foods.

Lichens play an essential ecological and economic role in northern ecosystems. Their economic role is primarily linked to their importance as a food resource for semi-domesticated reindeer. Despite their importance, in Sweden, lichens have suffered tremendous habitat reductions in the last decades.