''Marchantia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

liverworts 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 ge ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Marchantiaceae Marchantiaceae is a family of liverworts in order Marchantiales. It contains a single genus ''Marchantia''. Genera in Marchantiaceae Until recently, three genera were included in the Marchantiaceae: * '' Bucegia'' Radian 1903 * ''Marchantia'' ...

and the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Marchantiales Marchantiales is an order of thallose liverworts (also known as "complex thalloid liverworts") that includes species like ''Marchantia polymorpha'', a widespread plant often found beside rivers, and '' Lunularia cruciata'', a common and often tr ...

. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores and a lower storage layer. The thallus features tiny cup-like structures called gemma cups, containing gemmae, small packets of tissue that are used for asexual reproduction. The combination of barrel-shaped pores and the circular shape of the gemma cups are diagnostic of the genus. Multicellular purple colored scales with single cell thickness and unicellular rhizoids are present on the ventral surface of the thallus.

Reproduction

''Marchantia'' can reproduce both sexually and asexually. Sexual reproduction involves sperm from

antheridia An antheridium is a haploid structure or organ producing and containing male gametes (called ''antherozoids'' or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. Androecium is also t ...

on the male plant

fertilizing Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...

an ovum (egg cell) in the

archegonium An archegonium (pl: archegonia), from the ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female ga ...

of a female plant. The antheridia and archegonia are borne atop special

gametophore Gametophores are prominent structures in seedless plants on which the reproductive organs are borne. The word gametophore and ‘-phore’ (Greek Φορά, "to be carried"). In mosses, liverworts and ferns (Archegoniata), the gametophores support ...

stalks called antheridiophores and archegoniophores, respectively. These are borne on separate thalli and thus the plants are

dioicous Dioicy () is a sexual system where archegonia and antheridia are produced on separate gametophytes. It is one of the two main sexual systems in bryophytes. Both dioicous () and monoicous gametophytes produce gametes in gametangia by mitosis rathe ...

. Once fertilized, the ovum is called a

zygote A zygote (, ) is a eukaryotic cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. In multicellula ...

and develops into a small

sporophyte A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote pr ...

plant, which remains attached to the larger

gametophyte A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has on ...

plant. The sporophyte produces

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 ...

s which develop into free-living male and female gametophyte plants. Asexual reproduction occurs by means of gemmae, discoid clumps of cells which are genetically identical to the parent and contained in cup-like structures on the upper surface of the plant. These are dispersed when rain splashes into the cups and develop into new plants. Asexual reproduction can also occur when older parts of the plant die and the surviving newer branches develop into separate plants.

Species

* ''

Marchantia alpestris ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with por ...

'' * ''

Marchantia aquatica ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * '' Marchantia berteroana'' * ''

Marchantia carrii ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * ''

Marchantia chenopoda ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with por ...

'' * ''

Marchantia debilis ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with por ...

'' * ''

Marchantia domingenis ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * ''

Marchantia emarginata ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with por ...

'' * ''

Marchantia foliacia ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * ''

Marchantia grossibarba ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * ''

Marchantia inflexa ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * ''

Marchantia linearis ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * '' Marchantia macropora'' * '' Marchantia novoguineensis'' * '' Marchantia paleacea'' * '' Marchantia palmata'' * '' Marchantia papillata'' * ''

Marchantia pappeana ''Marchantia'' is a genus of Marchantiophyta, liverworts in the Family (biology), family Marchantiaceae and the Order (biology), order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic l ...

'' * ''

Marchantia polymorpha ''Marchantia polymorpha'' is a species of large thalloid liverwort in the class Marchantiopsida. ''M. polymorpha'' is highly variable in appearance and contains several subspecies. This species is dioicous, having separate male and female plants. ...

'' (also as ''M. aquatica'') * '' Marchantia rubribarba'' * ''

Marchantia solomonensis ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

'' * '' Marchantia streimannii'' * '' Marchantia subgeminata'' * '' Marchantia vitiensis'' * '' Marchantia wallisii'' * ''

Marchantia nepalensis ''Marchantia'' is a genus of liverworts in the family Marchantiaceae and the order Marchantiales. The thallus of ''Marchantia'' shows differentiation into two layers: an upper photosynthetic layer with a well-defined upper epidermis with pores ...

References

External links

* * Marchantiales Marchantiales genera {{Bryophyte-stub