Fruiting body a stalked sporangium. Stalk consisting of an interlaced system of fibres, the upper portion usually opaque. Hypothallus usually small, discoid but sometimes contiguous for a group of sporangia. Peridium fugacious or rather persistent and always leaving a collar around the stalk, to which the capillitium may be attached. Columella reaching to about the middle of the sporotheca. Capillitium with flexuose branches, these arising mostly from the apex of the columella but sometimes also from along the sides of the columella, branches dividing and anastomosing into an internal net, usually with free ends at the surface. Spores usually black to deep purple brown or rarely pinkish brown.
Five species of Collaria have been described (Lado 2001), only two of which are known from New Zealand.