Gleichenia | |
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Gleichenia microphylla, Mornington Peninsula, Victoria | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Gleicheniales |
Family: | Gleicheniaceae |
Genus: | Gleichenia Sm. |
Type species | |
Gleichenia polypodioides (L.) Smith
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Species | |
See text | |
Synonyms[1] | |
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Gleichenia is a genus of ferns.[2] Its closest relative is the genus Stromatopteris,[3] restricted to New Caledonia.
These ferns have creeping rhizomes. The compound eaves fork multiple times, with the final leaf lobes ending in a pinnate arrangement. The sori are found at the bottom of the leaves and are made of a few sporangia. They are not covered by an indusium (protective covering).[4] The sori occur in a unique chamber in the laminar pits - a feature found only in this genus.[5]
The fossil record indicates that this genus had emerged by the late Jurassic period, although it was far more common in the early Cretaceous period.[6] There is some evidence that it may have emerged even earlier - in the upper Triassic period.[7] There are, however, multiple genera in the fossil record that show a similar leaf branching pattern to Gleichenia, which can make it difficult to determine the exact identity of a specimen that does not have adequately preserved fruiting bodies.[8]
Fossils have been found in across a wide geographic range including:
The following species are recognised as of February 2023:[1][2][11][12]
Phylogeny of Gleichenia[13][14]
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Unassigned species: