''Pteris platyzomopsis'',

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

''Platyzoma microphyllum'', is a species of fern in the family Pteridaceae. When placed in the genus ''Platyzoma'', it was the only species; the genus was sometimes placed in its own family, Platyzomaceae. The species is native to northern Australia, occurring in the

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region of Western Australia, in the Northern Territory and Queensland, and in northern New South Wales, where it is considered endangered. Vernacular names include braid fern.

Characteristics

''Pteris platyzomopsis'' is unusual among ferns in that it may display incipient heterospory. Microsporangia produce 32 microspores, each 71-101μm in diameter. Megasporangia produce 16 megaspores, each 163-183μm in diameter. Microspores produce a filamentous microgametophyte, which lacks rhizoids and gives rise only to antheridia. Megaspores produce spatulate megagametophytes with rhizoids, which produce archegonia. Megagametophytes may later produce antheridia, making them functionally bisexual. Development of gametophytes is not endosporic.

Taxonomy

''Pteris platyzomopsis'' has been known by the synonym ''Platyzoma microphyllum''. The genus ''Platyzoma'' has been placed as the only species in family Platyzomataceae. Tryon has speculated that the species, with its incipient heterospory, unusual chromosome number (2n=78) and other features, may represent a stage transitional to the heterosporous aquatic ferns. In 1827 Nicaise Auguste Desvaux included in ''Platyzoma'' additional species, such as ''

Gleichenia alpina ''Gleichenia alpina'', commonly known as alpine coral-fern, is a small fern species that occurs in Tasmania and New Zealand. It grows in alpine and subalpine areas with moist soils and is a part of the Gleichrniaceae family. The species was fir ...

'', ''

Gleichenia dicarpa ''Gleichenia dicarpa'', commonly known as pouched coral fern or tangle fern, is a small fern of the family Gleicheniaceae found in eastern Australia, New Caledonia and New Zealand. It forms tangled thickets in wet places such as swamps and rive ...

'' and ''

Gleichenia rupestris ''Gleichenia rupestris'' is a small fern growing in eastern Australia. Referred to as one of the coral ferns. The specific epithet ''rupestris'' refers to it being seen growing near rocks. A common plant, often seen growing under waterfalls, in ...

'', which are currently regarded by most scholars as part of the genus '' Gleichenia. In 2011,

Christenhusz Dr Maarten Joost Maria Christenhusz (born 27 April 1976) is a Dutch botanist, natural historian and photographer. Career He was born in Enschede, the Netherlands, received his undergraduate and master's degrees from Utrecht University in Bi ...

''et al.'' placed ''Platyzoma'' within the genus ''

Pteris ''Pteris'' (brake) is a genus of about 300 species of ferns in the subfamily Pteridoideae of the family Pteridaceae. They are native to tropical and subtropical regions, southward to New Zealand, Australia, and South Africa, north to Japan an ...

'' and transferred the to , as the name ''Pteris microphylla'' was already in use. The transfer is accepted by the ''Checklist of Ferns and Lycophytes of the World'' and ''

Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...

''.

References

* * * {{Taxonbar, from1=Q17117248, from2=Q7202864 platyzomopsis Flora of New South Wales Flora of Queensland Flora of the Northern Territory Flora of Western Australia Ferns of Australia