Cystodium sorbifolium

Cystodium
Scientific classification
Kingdom:	Plantae
Division:	Pteridophyta
Class:	Polypodiopsida /   Pteridopsida (disputed)
Order:	Polypodiales
Family:	Cystodiaceae J.R.Croft 1986
Genus:	Cystodium J.Sm. 1841
Species:	C. sorbifolium
Binomial name
Cystodium sorbifolium (Sm.) J.Sm.
Synonyms
Cystodiopteris Rauschert 1982[1]

Cystodium is a fern genus in its own Cystodiaceae family.^[2] It contains a single species: Cystodium sorbifolium (Sm.) J.Sm. 1841.^[3] Because it looks like a small tree fern, it had previously been placed in the tree fern family Dicksoniaceae. 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]

Distribution

Cystodium is distributed through lowland rainforests from Borneo to New Guinea and nearby islands, as well as the Solomon Islands.^[3]

References

1. Cystodiopteris USDA-ARS Germplasm Resources Information Network (GRIN) 28 January 2010
2. Christenhusz, Maarten; Xian-Chun Zhang & Harald Schneider (2011). "A linear sequence of extant families and genera of lycophytes and ferns" (PDF). Phytotaxa. 19 (18 Feb. 2011): 7–54.
3. Korall, Petra; Conant, David S.; Schneider, Harald; Ueda, Kunihiko; Nishida, Harufumi; Pryer, Kathleen M. (2006). "On the Phylogenetic Position of Cystodium: It's Not a Tree Fern – It's a Polypod!" (PDF). American Fern Journal. 96 (2): 45–53. doi:10.1640/0002-8444(2006)96[45:OTPPOC]2.0.CO;2.
4. Lehtonen, Samuli; Tuomisto, Hanna; Rouhan, Germinal; Christenhusz, Maarten J. M. (2010). "Phylogenetics and classification of the pantropical fern family Lindsaeaceae". Botanical Journal of the Linnean Society. 163 (3): 305–359. doi:10.1111/j.1095-8339.2010.01063.x.