PDD 74406, 74407, 74408.

Fruiting body a sessile sporangium (or rarely plasmodiocarpous), gregarious to crowded, subglobose to hemispherical or pulvinate, sometimes slightly constricted at the base, 0.4–1.5 mm in diameter and 0.4–1.0 mm high. Hypothallus membranous, translucent, colourless, inconspicuous when limeless but frequently frosted with white lime and then evident. Peridium consisting of two layers, the outer layer crustose, densely calcareous, dull yellow-brown, the lime tending to flake off in patches, the inner layer membranous, sometimes iridescent, dehiscence irregular. Columella absent. Capillitium dense, consisting of large, yellow, branched lime nodes connected by a few, very short, hyaline filaments. Spores brownish black in mass, medium purple-brown by transmitted light, closely and evenly and minutely warted, 10–11 µm in diameter. Plasmodium greenish yellow.

Recorded from Europe, North America, and South America (Martin & Alexopoulos 1969, Farr 1974, Mitchel et al. 1986). First reported from New Zealand by Stephenson & Johnston (2003), based on specimens collected in Otago Lakes and Central Otago.

Various types of plant debris or (more rarely) living plants, usually near the edges of melting snowbanks in alpine regions.

Martin & Alexopoulos (1969), Mitchel et al. (1986), Neubert et al. (1995).

Physarum alpinum and P. albescens occur in the same types of ecological situations, but fruiting bodies of the latter usually have a weak, strand-like stalk and the lime present on the outer layer of the peridium does not tend to flake off in patches