Members of this family typically have dark coloured spore mass. The typical type of fruiting body produced is a stalked sporangium. A capillitium is always present and many species have a prominent columella.

Sporangia stalked or sessile. Sporangial wall hyaline, iri descent, without deposits of lime. Walls of stalk and columella membranous, charged with lime in the form of granules or crystalline nodules, sometimes without lime. Capillitium a profuse network of purplish threads without lime.

Sporangia usually stalked, rarely sessile, globose or ellipsoid; sporangial wall membranous, somewhat persistent, shining with iridescent colors; stalk black; columella cylindrical or clavate, usually reaching to half or more than half the height of the sporangium; capillitium consisting of branched, anastomosing threads, radiating chiefly from the upper part of the columella.

Sporangia cylindrical, stalked, distinct or fasciculate; stalk solid, black, extending to near the apex as a columella, except in confluent forms; capillitium composed of numerous threads radiating from all parts of the columella and combined into a loose network, the ultimate branches united into a surface-net, often incomplete in irregular developments