''Radula'' is a genus of liverwort, and is the only genus in family Radulaceae. It is a leafy liverwort. The appearance of the plants are as a scaly, green surface on the trunk of a tree, log or rock in a sheltered, moist out-door environment. The leaves are rounded, overlapping and consist of two unequal lobes. The smaller lobe is folded beneath the larger one. The oldest fossil species is ''Radula cretacea'' from the

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

aged Burmese amber of Myanmar, belonging to the

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

'' Odontoradula.'' Molecular evidence suggests that the genus arose during the Triassic, around 227.8 Ma, and the

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

began to diversify during the Early Jurassic, around 176.3 Ma. Species include: * '' Radula boninensis'' * '' Radula carringtonii'' J.B.Jack * '' Radula cavifolia'' * ''

Radula complanata The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

'' * ''

Radula deflexilobula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

'' Promma, L.N.Zhang et R.L.Zhu * ''

Radula demissa ''Radula demissa'' is a species of liverwort. Distribution The species is found in Australia and New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the ...

'' M.A.M.Renner, 2013 * ''

Radula javanica The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

'' * ''

Radula jonesii ''Radula jonesii'' is a species of liverwort in the family Radulaceae. It is known from a few locations on Madeira and one location on Tenerife. The populations are small and vulnerable. This liverwort forms dark green to olive green mats on roc ...

'' Bouman, Dirkse & Yamada * ''

Radula kojana The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

'' * ''

Radula laxiramea The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

'' * ''

Radula marginata ''Radula marginata'', or Wairuakohu, is a species of plant in the genus ''Radula'', a genus of liverworts. It is endemic to New Zealand. It has been found to contain cannabinoids. Cannabinoids Users smoking the plant have experienced differe ...

'' * ''

Radula obtusiloba The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

'' * ''

Radula perrottetii ''Radula perrottetii'' is a species of plant in genus ''Radula'', a genus of liverworts. It is endemic in Japan. It contains the small molecule perrottetinene a cannabinoid Cannabinoids () are several structural classes of compounds found in th ...

'' * ''

Radula visianica ''Radula visianica'' is a species of liverwort in the Radulaceae family. It is European Alps endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other d ...

'' C. Massal.

References

External links

* * * Porellales Porellales genera {{bryophyte-stub