[1] In 1886, a New Zealand fungus similar to the beech orange was described as Cyttaria purdiei; later, however, the two species were assumed to be the same.

A molecular study has now found the Australian and New Zealand fungi known as C. gunnii to be two distinct species.

"[4] The evolution of the genus parallels that of the host genus Nothofagus; hence C. septentrionalis, the closest relative, parasitises Antarctic beech (Nothofagus moorei), the closest relative of myrtle beech.

[5] The fungi form globose woody galls on their host trees, though they do not appear to spread through them.

[3] Said to resemble bunches of grapes, the fruit bodies appear in clusters in late spring and summer (November to January).