''Marchantia'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of
liverworts in the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Marchantiaceae and the
order 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 trou ...
.
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 ...
on the male plant
fertilizing an ovum (egg cell) in the
archegonium of a female plant. The antheridia and archegonia are borne atop special
gametophore stalks called antheridiophores and archegoniophores, respectively. These are borne on separate thalli and thus the plants are
dioicous.
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 multicell ...
and develops into a small
sporophyte plant, which remains attached to the larger
gametophyte
A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the ...
plant. The sporophyte produces
spores 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 aquatica''
* ''
Marchantia berteroana''
* ''
Marchantia carrii''
* ''
Marchantia chenopoda''
* ''
Marchantia debilis''
* ''
Marchantia domingenis''
* ''
Marchantia emarginata''
* ''
Marchantia foliacia''
* ''
Marchantia grossibarba''
* ''
Marchantia inflexa''
* ''
Marchantia linearis''
* ''
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