Cystodiopteris Rauschert 1982[1] Cystodium is a fern in its own family, Cystodiaceae.

[2] It contains a single species: Cystodium sorbifolium (Sm.)

Subsequent analysis had moved it to the Lindsaeaceae,[3] but the most recent phylogenetic studies have placed it in its own separate family, Cystodiaceae, with a sister relationship to the current Lindsaeaceae.

[4] A fossil species of the genus Cystodium sorbifolioides is known from the Cenomanian aged Burmese amber in Myanmar.

[5] Cystodium is distributed through lowland rainforests from Borneo to New Guinea and nearby islands, as well as the Solomon Islands.