Plasmodial slime moulds (myxomycetes) in Swedish and Nordic folk biology.

Background: Folk biology commonly contains knowledge of many more taxa than those of immediate economic importance. Species with little or no practical use are, however, often overlooked by ethnobiological research. An example are a few Myxomycetes taxa which played an important role in the folk biology and beliefs of pre-industrial Sweden and adjacent Nordic countries, Denmark, Norway and Finland. Such organisms are not of less interest for the understanding of human-biota relationships; local knowledge about the entire biota in a given environment should therefore be studied to comprehend the full range of folk biology.

Methodology: This qualitative study analyses and reviews historical data available in archives and published ethnographic collections as well as scattered and fragmentary notes in the literature using a historical ethnobiological approach.

Results: Peasants in the Nordic countries recognized three taxa of myxomycetes. Scrambled egg slime, Fuligo septica (L.) F.H.Wigg., in particular attracted interest and is known by many local folk names. This slime had no practical value or use, yet it was well known in folk biology and associated with a supernatural malevolent being which in the shape of a hare or cat stole milk or butter on behalf of a witch. The belief in evil origins of slime became the cause of violent actions such as whipping and burning of the organism. Two other taxa, Lycogala epidendron (L.) Fr. and Mucilago crustacea F.H.Wigg., have also been observed in folk biology, but data on how they were perceived and treated is sparse.

Conclusions: The sudden appearance of strange shapes and clear colours of myxomycetes in damp weather created both fear and curiosity; these odd organisms required explanations, interpretations and actions. Our example of the economically irrelevant myxomycetes in Sweden and nearby Nordic countries indicates that interpretations in pre-industrial societies of natural phenomena and various organisms, connections with beliefs and perceptions about the surrounding environment and the possible consequent actions should be studied alongside economic plants and animals in ethnobiological research, for a deeper understanding about folk biology and the multilayered and multidimensional relationships between humans and biota.