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 | |
Species | |
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: