CHSC 50090, BPI 819639.

Fruiting body a sessile sporangium or plasmodiocarp, often crowded, globose, 0.5–0.8 mm in diameter; the plasmodiocarps usually short, simple or branched, but sometimes several millimeters long. Hypothallus membranous, varying from inconspicuous to contiguous for a group of sporangia, white. Peridium consisting of a single layer, membranous, rugulose, usually densely covered with coarse, closely set, calcareous granules, rarely nearly limeless, greyish white, dehiscence more or less irregular. Capillitium consisting of large, angular, branching, limy nodes connected by short, hyaline threads, the nodes sometimes massed in the center to form a pseudocolumella. Spores black in mass, dark purplish brown by transmitted light, warted, 10–12 µm in diameter. Plasmodium white.

Widespread but not common in the Northern Hemisphere and also reported from Australia (Cheesman & Lister 1915) and South America (Martin & Alexopoulos 1969, Farr 1976). First reported from New Zealand by Rawson (1937), based on a specimen from Dunedin. Also known from Westland and Otago Lakes (Stagg 1982).

Leaf litter and other types of plant debris, often near the edges of melting snowbanks in alpine regions but not restricted to such ecological situations.

Martin & Alexopoulos (1969), Neubert et al. (1995), Ing (1999).

Physarum vernum is highly variable and probably represents a species complex rather than a single taxonomic entity (Farr 1976). It is similar morphologically to P. cinereum but tends to be larger, usually forms longer plasmodiocarps, and has larger and darker spores (Ing 1999).