Members of the Cyttariaceae are obligate parasites of Nothofagus (southern beeches). They produce spherical to lobed, sponge‑like fruitbodies that emerge from woody galls induced in the host. The fruitbodies are often yellow, orange, or pale cream, with a pitted or honeycombed surface.

Cyttaria is a Southern Hemisphere genus of brightly coloured, pitted, globose ascomata that grow from galls on Nothofagus. They are among the most distinctive fungi in the region.