PDD 3644, 73121.

Fruiting body a stalked (or rarely sessile) sporangium, gregarious, 1–2 mm tall. Sporotheca discoid, often slightly depressed above and umbilicate below, 0.6–1.4 mm in diameter. Stalk rather thick, cylindrical, grooved, usually short but sometimes up to 1 mm tall, furrowed, ochraceous. Hypothallus discoid, membranous, colourless to white. Peridium consisting of two layers, the outer layer cartilaginous, smooth above, thickened and rugose below, white, composed of globose lime granules, the inner layer membranous, delicate, cinereous, dehiscence more or less circumscissile. Columella broad, flat, pale or dark brown, calcareous. Capillitium delicate, scanty to abundant, consisting of sparsely branched, colouress to pale violet-brown filaments. Spores dark brown in mass, pale yellow or violaceous brown by transmitted light, very minutely warted, the warts often clustered, 10–11 µm in diameter. Plasmodium opaque white.

Considered to be cosmopolitan by Martin & Alexopoulos (1969) but apparently uncommon at high latitudes (Stephenson et al. 2000). First reported from New Zealand by Macbride (1926), based on a specimen collected in Mid Canterbury. Also known from Auckland.

Leaf litter and other types of plant debris, occasionally on decaying wood.

Martin & Alexopoulos (1969), Nannenga-Bremekamp (1991), Neubert et al. (1995), Ing (1999).

The fruiting bodies of Diderma hemisphaericum, which resemble miniature mushrooms, are distinctive. The only morphologically similar species is Didymium clavus, which has a quite different peridium.