''Polypodium'' is a genus of ferns in the family Polypodiaceae, subfamily Polypodioideae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). The genus is widely distributed throughout the world, with the highest species diversity in the tropics. The name is derived from Ancient Greek ''poly'' ("many") + ''podion'' ("little foot"), on account of the foot-like appearance of the rhizome and its branches. They are commonly called polypodies or rockcap ferns, but for many species unique vernacular names exist. They are terrestrial plant, terrestrial or epiphyte, epiphytic ferns, with a creeping, densely hairy or scaly rhizome bearing fronds at intervals along its length. The species differ in size and general appearance and in the character of the fronds, which are evergreen, persisting for 1–2 years, pinnate or pinnatifid (rarely simple entire), and from 10 to 80 cm or more long. The sorus, sori or groups of spore-cases (sporangia) are borne on the back of the frond; they are globose and naked, not covered with a membrane (indusium). Polypodies have some use in herbalism, but are today most important in horticulture where several species, hybrids, and their cultivars like ''Polypodium'' 'Green Wave' are commonly used as ornamental plants for shady locations. ''Polypodium'' have a bitter-sweet taste and are among the rather few ferns that are used in cooking; in this case as a spice e.g. for nougat.

Species

Several of the species form hybrid (biology), hybrids with other species in the genus; these may often be distinguished by being sterile, with very small "blind" sori. , ''Checklist of Ferns and Lycophytes of the World'' accepted the following forty-seven species and eight hybrids: A number of species formerly included in the genus have recently been transferred to other genera, including ''Campyloneurum'', ''Cyathea'', ''Microgramma (plant), Microgramma'', ''Nephrolepis'', ''Pecluma'', ''Phlebodium'', ''Pleopeltis'' and ''Serpocaulon''. Species placed elsewhere include: * ''Polypodium argyrolepis'' = ''Serpocaulon lasiopus'' * ''Polypodium mindense'' = ''Serpocaulon eleutherophlebium'' * ''Polypodium mixtum'' = ''Pleopeltis murora'' * ''Polypodium piligerum'' = ''Moranopteris achilleifolia'' * ''Polypodium punctatum'' Thunb. ex Murray = ''Hypolepis punctata'' * ''Polypodium quitense'' = ''Pecluma dulcis'' * ''Polypodium rimbachii'' = ''Serpocaulon sessilifolium'' * ''Polypodium scutulatum'' = ''Serpocaulon fraxinifolium''

References

* Haufler, Christopher H.; Windham, Michael D.; Lang, Frank A. & Whitmore, S.A. (1993)
2. ''Polypodium'' Linnaeus
''In: Flora of North America North of Mexico'', Vol. 2 (Pteridophytes and Gymnosperms): 315–323. * Hyde, H.A.; Wade, A.E. & Harrison, S.G. (1978): ''Welsh Ferns''. National Museum of Wales. * Royal Botanic Garden Edinburgh (RBGE) (2007): Digital Flora Europaea
''Polypodium'' species list
Retrieved 2007-NOV-26. * United States Department of Agriculture (USDA) (2007a): Germplasm Resources Information Network
''Polypodium''
Retrieved 2007-NOV-26.

External links

* * * {{Authority control Polypodium, Fern genera Epiphytes