''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 n ...
of
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 g ...
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
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 ...
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 tro ...
.
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. Proc ...
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 gam ...
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 suppor ...
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 ra ...
.
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 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, ...
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 aquatica''
* ''
Marchantia berteroana''
* ''
Marchantia carrii''
* ''
Marchantia chenopoda''
* ''
Marchantia debilis''
* ''
Marchantia domingenis''
* ''
Marchantia emarginata''
* ''
Marchantia foliacia''
* ''
Marchantia grossibarba''
* ''
Marchantia inflexa''
* ''
Marchantia linearis''
* ''
Marchantia macropora
''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 novoguineensis''
* ''
Marchantia paleacea
''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 palmata''
* ''
Marchantia papillata
''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 pappeana
''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 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 streimannii
''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 subgeminata
''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 vitiensis
''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 wallisii''
* ''
Marchantia nepalensis''
References
External links
*
*
Marchantiales
Marchantiales genera
{{Bryophyte-stub