Abstract: A new species of Myxomycetes, Physarum apiculosporum Härkönen, is described from Finland. It was first obtained on Hordeum seeds in moist chamber culture. It resembles Physarum ovisporum G. Lister in being grey, sessile, sporangiate or plasmodiocarpous and having oval spores. The spores differ from those of P. ovisporum in being more oval, bigger, darker, smooth and apiculate. It was possible to cultivate the species from spore to spore in a simple medium of boiled A vena seeds on filter paper in a Petri dish.