Diderma effusum

Diderma effusum can be recognised by the typical depressed, smooth, white sporangia or plasmodiocarpic fructification bodies and by its rather small pale spores.     Easily overlooked in the field due to its size and its prefered substrate of dried leaf on the forest floor.

Fructification structures composed of flattened white sporangia massed in plasmodiocarpous fashion, applanate, reticulate, or often forming a broadly effused low pulvinate, 0.2–0.4 mm height, ovoid or longer than wide to oblong, 0.5–1.5 mm wide and 0.6 to well over 1 cm long.

Hypothallus is common to a group, membranous and inconspicuous.

Peridium of two separated layers, the outer a thin, smooth, white or almost white, calcareous crust closely applied to the delicate membranous and the inner wall membranous as well as colourless or rose-lilac dehiscing irregularly but not together.

Columella, depressed pulvinate and white to reddish brown, sometimes limited to a thin layer of lime on the base, and covering most of the base.

Capillitium thin, colourless or pale lilac–brown, consisting of abundant short threads somewhat branched toward their distal extremities with few interconnections.

Spores in mass brown and lilac-brown in transmitted light, verruculose with faint clusters of larger warts, seeming almost smooth, some in denser groups, 8–10 μm in diameter.

Plasmodium is white colour