Plasmodial slime moulds (Myxomycetes) in Swedish and Nordic folk biology

Abstract Background A few Myxomycetes taxa played an important role in the folk biology of pre-industrial Sweden and adjacent Nordic countries (Denmark, Norway, Finland) in northern Europe. Folk biology commonly contains knowledge of far more taxa than those of immediate economic importance. The species of little or no practical use are often overlooked by ethnobiological research, but these organisms are not of less interest for the understanding of human relationships with biota. Local knowledge about the entire biota in a given environment must therefore be studied to comprehend folk biology. Methodology This qualitative study analyses and reviews historical data available in archives and published ethnographic collections as well as scattered notes in 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., attracted interest in particular and is known by many local folk names. Scrambled egg slime had no practical value, yet it was well known in folk biology and associated with a supernatural malevolent being in the shape of a hare or cat, which on behalf of a witch stole milk or butter. This belief caused 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 is sparse. Conclusions The sudden appearance of strange shapes and clear colours of myxomycetes in damp weather created both fear and curiosity, and 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 possible consequent actions should be studied alongside economic plants and animals, providing a deeper understanding for the ethnobiological study of folk biology and highlighting the multidimensional relationships between humans and biota.