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

ferns 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 th ...

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 s ...

. 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''.

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, ...

-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'', 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 eliminatum ''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".

'' – status uncertain **''

Ophioglossum gomezianum ''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 gujaratensis'' **'' Ophioglossum hitkishorei'' **'' Ophioglossum indicum'' **'' Ophioglossum isanensis'' **''

Ophioglossum malviae ''Ophioglossum malviae'' is a species of fern in the genus ''Ophioglossum ''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 ...

'' **''

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".

'' **'' Ophioglossum raphaelianum'' **''

Ophioglossum rubellum ''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".

'' *''Haukia'' **''

Ophioglossum crotalophoroides ''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 opacum'' **'' Ophioglossum tuberosum'' *''Whittieria'' **''

Ophioglossum engelmannii ''Ophioglossum engelmannii'', commonly known as the limestone adder's-tongue, is a species of fern native to the Western Hemisphere. It is widespread and native to the United States, Mexico, and Central America. Its primary natural habitat is dry ...

'' *''Ophioglossum'' s.s. **'' Ophioglossum ammophilum'' – sometimes included in ''O. gomezianum'' **''

Ophioglossum austroasiaticum ''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. 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 north ...

'' **'' Ophioglossum californicum'' **'' Ophioglossum caroticaule'' **'' Ophioglossum convexum'' **''

Ophioglossum coriaceum ''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 fernandezianum'' – doubtful species ** ''Ophioglossum'' × ''giovanninii'' **'' Ophioglossum gracile'' – may be included in ''O. gramineum'' **'' Ophioglossum gracillimum'' **'' Ophioglossum gramineum'' **'' Ophioglossum harrisii'' **'' Ophioglossum jaykrishnae'' – provisionally accepted name **'' Ophioglossum kawamurae'' **''

Ophioglossum lancifolium ''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 latifolium'' **'' Ophioglossum lineare'' – possibly a synonym of ''O. parvifolium'' **'' Ophioglossum louisii'' **'' Ophioglossum lusitanicum'' **'' Ophioglossum lusoafricanum'' **'' Ophioglossum melipillense'' **''

Ophioglossum namegatae ''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".

'' – probably a synonym of ''O. petiolatum'' **'' Ophioglossum oblongum'' **'' Ophioglossum parvifolium'' **'' Ophioglossum parvum'' **'' Ophioglossum petiolatum'' ** ''Ophioglossum'' × ''pierinii'' **''

Ophioglossum polyphyllum ''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'' × ''pseudoazoricum'' **''

Ophioglossum pusillum ''Ophioglossum pusillum'' is a species of fern in the family Ophioglossaceae known by the common name northern adder's tongue. It is native to northern North America, where it is widespread in moist areas such as marshes, fens, and meadows. It i ...

'' **''

Ophioglossum reticulatum ''Ophioglossum reticulatum'', the netted adder's-tongue, is a species of fern in the family Ophioglossaceae Ophioglossaceae, the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 ( ...

'' **'' Ophioglossum sandieae'' **'' Ophioglossum scariosum'' **'' Ophioglossum thermale'' **'' Ophioglossum thomasii'' **''

Ophioglossum trilokinathii ''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 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 chr ...

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