''Radula'' is a genus of

liverwort The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of g ...

, 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 Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The ...

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 The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

, 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 The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-J ...

, around 176.3 Ma. Species include: * '' Radula boninensis'' * '' Radula carringtonii'' J.B.Jack * '' Radula cavifolia'' * '' Radula complanata'' * '' Radula deflexilobula'' Promma, L.N.Zhang et R.L.Zhu * '' Radula demissa'' M.A.M.Renner, 2013 * '' Radula javanica'' * '' Radula jonesii'' Bouman, Dirkse & Yamada * '' Radula kojana'' * '' Radula laxiramea'' * ''

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'' * ''

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'' C. Massal.

References

External links

* * * Porellales Porellales genera {{bryophyte-stub