Ophioglossum

Adders-tongues are so-called because the spore-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. ==Polyploidy==

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. The species Ophioglossum reticulatum has the highest number of chromosomes found in any multicellular organism. ==Taxonomy==

The Smith et al. classification of 2006, based on molecular phylogeny, placed Ophioglossum in Ophioglossaceae. Subsequent classifications have maintained this placement.{{cite journal |last1=Christenhusz |first1=Maarten J. M. |author-link1=Maarten J. M. Christenhusz |last2=Zhang |first2=Xian-Chun |last3=Schneider |first3=Harald |year=2011 |title=A linear sequence of extant families and genera of lycophytes and ferns ==Phylogeny==

Phylogeny of Ophioglossum }} Unassigned species: • (Goswamia) • Ophioglossum gujaratensis • Ophioglossum hitkishorei • Ophioglossum indicum • Ophioglossum isanensis • Ophioglossum malviae • Ophioglossum raphaelianum • (Haukia) • Ophioglossum opacum • Ophioglossum tuberosum • (Ophioglossum) s.s. • Ophioglossum ammophilum – sometimes included in O. gomezianum • Ophioglossum azoricum • Ophioglossum caroticaule • Ophioglossum convexum • †Ophioglossum eocenum (Massalongo) Schimper • Ophioglossum fernandezianum – doubtful species • Ophioglossum × giovanninii • Ophioglossum gracile – may be included in O. gramineum • Ophioglossum gracillimum • †Ophioglossum granulatum Heer • Ophioglossum harrisii • Ophioglossum jaykrishnae – provisionally accepted name • Ophioglossum latifolium • Ophioglossum lineare – possibly a synonym of O. parvifolium • Ophioglossum louisii • Ophioglossum loureirianum Presl • Ophioglossum melipillense • Ophioglossum oblongum • †Ophioglossum ornatum Faddeeva • Ophioglossum × pierinii • Ophioglossum × pseudoazoricum • Ophioglossum richardsiae Burrows • †Ophioglossum senomanicum Chlonova • Ophioglossum sandieae • Ophioglossum scariosum • Ophioglossum thomasii • Ophioglossum yongrenense Species that may be placed in this genus include: • Ophioglossum falcatum = Ophioderma falcatum • Ophioglossum intermedium = Ophioderma intermedium • Ophioglossum simplex = Ophioderma simplex ==References==