Marchantiales
Encyclopedia
Marchantiales is an order
of thallose liverwort
s that includes species like Lunularia cruciata
, a common and often troublesome weed in moist, temperate gardens and greenhouses.
As in other bryophyte
s, the gametophyte
generation is dominant, with the sporophyte
existing as a short-lived part of the life cycle
, dependent upon the gametophyte.
The genus
Marchantia
is often used to typify the order, although there are also many species of Asterella
and species of the genus Riccia
are more numerous.
The majority of genera are characterized by the presence of (a) special stalked vertical branches called archegoniophores or carocephala, and (b) sterile cells celled elater
s inside the sporangium.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of thallose liverwort
Marchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....
s that includes species like Lunularia cruciata
Lunularia cruciata
Lunularia cruciata or crescent-cup liverwort is a liverwort of order Marchantiales, and the only species in the genus Lunularia and family Lunulariaceae. The name refers to the moon-shaped cups, from Latin luna, moon. It occurs commonly in western Europe, where it is native the region around the...
, a common and often troublesome weed in moist, temperate gardens and greenhouses.
As in other bryophyte
Bryophyte
Bryophyte is a traditional name used to refer to all embryophytes that do not have true vascular tissue and are therefore called 'non-vascular plants'. Some bryophytes do have specialized tissues for the transport of water; however since these do not contain lignin, they are not considered to be...
s, the gametophyte
Gametophyte
A gametophyte is the haploid, multicellular phase of plants and algae that undergo alternation of generations, with each of its cells containing only a single set of chromosomes....
generation is dominant, with the sporophyte
Sporophyte
All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or algae that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants...
existing as a short-lived part of the life cycle
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
, dependent upon the gametophyte.
The genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Marchantia
Marchantia
Marchantia is a genus in the family Marchantiaceae of the order Marchantiales, a group of liverworts.These are simple plants without roots or vascular systems...
is often used to typify the order, although there are also many species of Asterella
Asterella
Asterella is a liverwort genus in the family of Aytoniaceae.- Species :* Asterella bolanderi, the Bolander's asterella* Asterella californica, the California asterella* Asterella elegans, the elegant asterella* Asterella elegans ssp...
and species of the genus Riccia
Riccia
Riccia is a genus of liverworts in the order Marchantiales. One of the more than 100 species in this genus is the "slender riccia" , which can be found floating in ponds, and is sometimes used in aquariums....
are more numerous.
The majority of genera are characterized by the presence of (a) special stalked vertical branches called archegoniophores or carocephala, and (b) sterile cells celled elater
Elater
An elater is a cell that is hygroscopic, and therefore will change shape in response to changes in moisture in the environment. Elaters come in a variety of forms, but are always associated with plant spores...
s inside the sporangium.
Classification
- AytoniaceaeAytoniaceaeAytoniaceae is a family of liverworts in order Marchantiales.Synonyms :Grimaldiaceae, K. Müll., 1940Rebouliaceae, Evans, 1923- Genera in Family Aytoniaceae :* Asterella* Cryptomitrium* Mannia...
- Cleveaceae
- Conocephalaceae
- CorsiniaceaeCorsiniaceaeCorsiniaceae is a family of liverworts in order Marchantiales....
- Cyathodiaceae
- Exormothecaceae
- Lunulariaceae
- MarchantiaceaeMarchantiaceaeMarchantiaceae is a family of liverworts in order Marchantiales.- Genera in Marchantiaceae :Currently, four genera are included in the Marchantiaceae:* Bucegia* Marchantia* Neohodgsonia* Preissia...
- Monocarpaceae
- Monosoleniaceae
- Oxymitraceae
- RicciaceaeRicciaceaeRicciaceae is a family of liverworts in order Marchantiales, with two genera.* Riccia* Ricciocarpos...
- Targioniaceae
- Wiesnerellaceae