The

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

genus ''Todea'' is known from only two living species. ''

Todea barbara ''Todea barbara'' is known as the king fern. Occurring in moist areas of south eastern Australia, and also indigenous to New Zealand and South Africa. Taxonomy Carl Linnaeus described the king fern in volume II of his '' Species Plantarum'' as ...

'' L., known as the king fern, is native to South Africa, New Zealand, and Australia while ''

Todea papuana Todea papuana, the Papuan king fern is a species of fern known only from Papua-New Guinea. It is a rather large species up to 2 m (7 feet) tall, with sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are forme ...

'' H. is known only from

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

. Species in the genus ''Todea'', as ''

Leptopteris The fern genus ''Leptopteris'' is a small group of plants found growing in the Pacific Islands, New Guinea and Australia. They are similar to ferns in the related genus ''Todea'', and were originally included in that genus. However, the very thi ...

'', are distinct from other in

Osmundaceae Osmundaceae (royal fern family) is a family of ferns containing four to six extant genera and 18–25 known species. It is the only living family of the order Osmundales in the class Polypodiopsida (ferns) or in some classifications the only ord ...

in that

sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cy ...

are born on laminar pinnules. So far the fossil record of the genus ''Todea'' consists only of the permineralized rhizome ''

Todea tidwellii ''Todea tidwellii'' is an extinct species of fern in the genus ''Todea''. Fossils have been recovered from the Late Cretaceous of British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated ...

'' from the Lower

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian Provinces and territories of Canada, province of British Columbia. The island is in length, in width at its widest point, and in total area, while are o ...

, Canada and the species ''Todea amissa'', known from the Eocene of

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

References

Bibliography

* Nathan Jud, Gar W.Rothwell and Ruth A. Stockey. 2008. "''Todea'' from the Lower Cretaceous of western North America: implications for the phylogeny, systematics, and evolution of modern Osmundaceae." American Journal of Botany, 95:330-339. * E.Hennipman. 1968. A new ''Todea'' from New Guinea, with remarks on the generic delimitation of recent Osmundaceae. Blumea 16: 105-108 * C.Michael Hogan. 2010
''Fern''. Encyclopedia of Earth. eds. Saikat Basu and C.Cleveland. National Council for Science and the Environment
Washington DC.

External links

- ''includes photos'' (author: David Nicholls, January 1998).'' Osmundales Ferns of Australasia Fern genera {{Polypodiidae-stub