''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family

Ophioglossaceae Ophioglossaceae, the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only family in the order Ophioglossales, which together with the Psilotales is placed in the sub ...

. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".eFloras: ''Ophioglossum''
accessed 14 February 2014. Their

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

is mainly in tropical and subtropical habitats. The genus has the largest number of chromosomes in the known plant kingdom, but contrary to popular belief does not have the largest number of chromosomes out of all known organisms, falling short to the protist ''

Sterkiella histriomuscorum ''Sterkiella histriomuscorum'', formerly ''Oxytricha trifallax'', is a ciliate species in the genus '' Sterkiella'', known for its highly fragmented genomes which have been used as a model for ciliate genetics. Genetics Like all ciliates, ''O. ...

''.

Description

Adders-tongues are so-called because the

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

-bearing stalk is thought to resemble a snake's tongue. Each plant typically sends up a small, undivided leaf blade with netted venation, and the spore stalk forks from the leaf stalk, terminating in sporangia which are partially concealed within a structure with slit sides. When the leaf blade is present, there is not always a spore stalk present, and the plants do not always send up a leaf, sometimes going for a year to a period of years living only under the soil, nourished by association with soil fungi. The plant grows from a central, budding, fleshy structure with fleshy, radiating roots.

Taxonomy

''Ophioglossum'' has a high chromosome count in comparison to other species, with 120 or up to 720 chromosomes possible in intervals of 120 due to polyploidy (multiple possible copies of chromosomes). It has almost 1260 number of chromosomes in the meiocyte (spore mother cell) which undergo meiosis, the reduction division to form the spore with only one set of chromosomes getting incorporated into each spore.

Species

, World Ferns listed the following species: *''Goswamia'' **'' Ophioglossum costatum'' **'' Ophioglossum eliminatum'' – status uncertain **'' Ophioglossum gomezianum'' **'' Ophioglossum gujaratensis'' **'' Ophioglossum hitkishorei'' **'' Ophioglossum indicum'' **'' Ophioglossum isanensis'' **''

Ophioglossum malviae ''Ophioglossum malviae'' is a species of fern in the genus ''Ophioglossum'' and found in the forests of Ahwa in the Dang District, India, Dang District of Gujarat. It is claimed to be the world's smallest land fern, with the entire plant growing ...

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Ophioglossum nudicaule ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

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Ophioglossum raphaelianum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **'' Ophioglossum rubellum'' *''Haukia'' **'' Ophioglossum crotalophoroides'' **''

Ophioglossum opacum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

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Ophioglossum tuberosum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' *''Whittieria'' **'' Ophioglossum engelmannii'' *''Ophioglossum'' s.s. **'' Ophioglossum ammophilum'' – sometimes included in ''O. gomezianum'' **'' Ophioglossum austroasiaticum'' – possibly a synonym of ''O. reticulatum'' **''

Ophioglossum azoricum ''Ophioglossum azoricum'', the small adder's-tongue fern or lesser adder's-tongue fern, is a small fern of the family Ophioglossaceae. Distribution ''Ophioglossum azoricum'' is an Atlantic–Mediterranean species native to islands in the nort ...

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Ophioglossum californicum ''Ophioglossum californicum'', known by the common name California adder's tongue, is an uncommon species of fern in the family Ophioglossaceae. The fern is native to California, and Baja California in Northwestern Mexico. It is found in the San ...

'' **'' Ophioglossum caroticaule'' **''

Ophioglossum convexum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **'' Ophioglossum coriaceum'' **'' Ophioglossum fernandezianum'' – doubtful species ** ''Ophioglossum'' × ''giovanninii'' **''

Ophioglossum gracile ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' – may be included in ''O. gramineum'' **'' Ophioglossum gracillimum'' **''

Ophioglossum gramineum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

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Ophioglossum harrisii ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **'' Ophioglossum jaykrishnae'' – provisionally accepted name **''

Ophioglossum kawamurae ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **'' Ophioglossum lancifolium'' **'' Ophioglossum latifolium'' **''

Ophioglossum lineare ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' – possibly a synonym of ''O. parvifolium'' **''

Ophioglossum louisii ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **''

Ophioglossum lusitanicum ''Ophioglossum lusitanicum'', the least adder's-tongue, is a small fern of the family Ophioglossaceae. It is a pan-tropically species categorised as least concern by the IUCN (2001). Description ''Ophioglossum lusitanicum'' is a small winter ...

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Ophioglossum lusoafricanum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **'' Ophioglossum melipillense'' **'' Ophioglossum namegatae'' – probably a synonym of ''O. petiolatum'' **''

Ophioglossum oblongum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

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Ophioglossum parvifolium ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **''

Ophioglossum parvum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of Fern, ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek language, Greek meaning "snake-tongue".

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Ophioglossum petiolatum ''Ophioglossum petiolatum'' is a species of fern in the family Ophioglossaceae. William Jackson Hooker named this species in 1823. The species occurs in parts of Asia, Australia, and North America. Common names According to Encyclopedia o ...

'' ** ''Ophioglossum'' × ''pierinii'' **'' Ophioglossum polyphyllum'' ** ''Ophioglossum'' × ''pseudoazoricum'' **'' Ophioglossum pusillum'' **'' Ophioglossum reticulatum'' **''

Ophioglossum sandieae ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **''

Ophioglossum scariosum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

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Ophioglossum thermale ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

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Ophioglossum thomasii ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' **'' Ophioglossum trilokinathii'' **''

Ophioglossum vulgatum ''Ophioglossum vulgatum'', commonly known as adder's-tongue, southern adders-tongue or adders-tongue fern, is a species of fern in the family ''Ophioglossaceae''. The adder’s tongue fern is generally believed to have the largest number of chro ...

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Ophioglossum yongrenense ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue".

'' Species that may be placed in this genus include: *''Ophioglossum bergianum'' = '' Rhizoglossum bergianum'' *''Ophioglossum falcatum'' = ''

Ophioderma falcatum ''Ophioderma falcatum'' is known as puapua moa or laukahi in Hawaii. It is a fern in the family Ophioglossaceae, and many people still classify it as an ''Ophioglossum''. Some consider it a subspecies of ''Ophioderma pendulum''. An epiphyte A ...

'' *''Ophioglossum intermedium'' = '' Ophioderma intermedium'' *''Ophioglossum simplex'' = '' Ophioderma simplex''

References

External links

Flora of North America: ''Ophioglossum'' (Adder's-tongue)
{{Taxonbar, from=Q781270 Ophioglossaceae Fern genera Taxa named by Carl Linnaeus