Chlorophyta or Prasinophyta is a

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep in the Charophyte alg ...

informally called chlorophytes. The name is used in two very different senses, so care is needed to determine the use by a particular author. In older classification systems, it refers to a highly

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

group of ''all'' the green algae within the green plants (

Viridiplantae Viridiplantae (literally "green plants") are a clade of eukaryotic organisms that comprise approximately 450,000–500,000 species and play important roles in both terrestrial and aquatic ecosystems. They are made up of the green algae, which a ...

) and thus includes about 7,000

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of mostly aquatic

photosynthetic Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in ...

eukaryotic Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bact ...

organisms. In newer classifications, it refers to the sister clade of the

streptophyte Streptophyta (), informally the streptophytes (, from the Greek ''strepto'' 'twisted', for the morphology of the sperm of some members), is a clade of plants. The composition of the clade varies considerably between authors, but the definition ...

charophytes Charophyta () is a group of freshwater green algae, called charophytes (), sometimes treated as a division, yet also as a superdivision or an unranked clade. The terrestrial plants, the Embryophyta emerged within Charophyta, possibly from terr ...

. The clade Streptophyta consists of the

Charophyta Charophyta () is a group of freshwater green algae, called charophytes (), sometimes treated as a division, yet also as a superdivision or an unranked clade. The terrestrial plants, the Embryophyta emerged within Charophyta, possibly from terr ...

in which the

Embryophyta The Embryophyta (), or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embryophytes () have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of green algae as sis ...

(land plants) emerged. In this latter sense the Chlorophyta includes only about 4,300 species. About 90% of all known species live in freshwater. Like the

land plants The Embryophyta (), or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embryophytes () have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of green algae as sist ...

(

embryophytes The Embryophyta (), or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embryophytes () have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of green algae as siste ...

bryophyte The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants ( embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited ...

s and

tracheophytes Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They a ...

), green algae (chlorophytes and charophytes besides embryophytes) contain chlorophyll a and

chlorophyll b } Chlorophyll ''b'' is a form of chlorophyll. Chlorophyll ''b'' helps in photosynthesis by absorbing light energy. It is more soluble than chlorophyll ''a'' in polar solvents because of its carbonyl group. Its color is green, and it primarily ...

and store food as

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...

in their

plastids The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids) is a membrane-bound organelle found in the cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosymbiotic cy ...

. With the exception of

Palmophyllophyceae The Palmophyllophyceae are a proposed basal Chlorophyte clade consisting of the Palmophyllales and Prasinococcales Prasinococcaceae is a family of green algae The green algae (singular: green alga) are a group consisting of the Prasinode ...

Trebouxiophyceae The Trebouxiophyceae are a class of green algae, in the division Chlorophyta. Their circumscription within the green algae is not well established due to the need for more genetic studies at higher levels within the group. Genera without inter ...

Ulvophyceae The Ulvophyceae or ulvophytes are a class of green algae, distinguished mainly on the basis of ultrastructural morphology, life cycle and molecular phylogenetic data.Graham LE, Graham JM, Wilcox LW (2009) ''Algae''. 2nd Edition. Benjamin Cumming ...

and

Chlorophyceae The Chlorophyceae are one of the classes of green algae, distinguished mainly on the basis of ultrastructural morphology. They are usually green due to the dominance of pigments chlorophyll a and chlorophyll b. The chloroplast A chlorop ...

, which show various degrees of multicellularity, all the Chlorophyta lineages are unicellular. Some members of the group form symbiotic relationships with

protozoa Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histor ...

, sponges, and cnidarians. Others form symbiotic relationships with fungi to form lichens, but the majority of species are free-living. Some conduct sexual reproduction, which is

oogamous Oogamy is an extreme form of anisogamy where the gametes differ in both size and form. In oogamy the large female gamete (also known as ovum) is immobile, while the small male gamete (also known as sperm) is mobile. Oogamy is a common form of ...

or isogamous. All members of the clade have motile flagellated swimming cells. While most species live in freshwater habitats and a large number in

marine habitats Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (the term ''marine'' comes from the Latin ''mare'', meaning sea or ocean). A habitat is an ecological or environmenta ...

, other species are adapted to a wide range of land environments. For example, ''Chlamydomonas nivalis'', which causes Watermelon snow, lives on summer alpine snowfields. Others, such as '' Trentepohlia'' species, live attached to rocks or woody parts of trees. ''

Monostroma kuroshiense ''Monostroma kuroshiense'', a green alga in the division Chlorophyta, is a green seaweed endemic to Kuroshio Coast of Japan. This high-value seaweed is called Hitoegusa or Hirohano hitoegusa (ヒロハノヒトエグサ) in Japanese. Previously ...

'', an edible green alga cultivated worldwide and most expensive among green algae, belongs to this group.

Ecology

Species of Chlorophyta (treated as what is now considered one of the two main clades of

) are common inhabitants of marine, freshwater and terrestrial environments.Graham LE, Graham JM, Wilcox LW (2009) ''Algae''. 2nd Edition. Benjamin Cummings (Pearson), San Francisco, CA Several species have adapted to specialised and extreme environments, such as deserts, arctic environments,

hypersaline A hypersaline lake is a landlocked body of water that contains significant concentrations of sodium chloride, brines, and other salts, with saline levels surpassing that of ocean water (3.5%, i.e. ). Specific microbial species can thrive in hig ...

habitats, marine deep waters, deep-sea hydrothermal vents and habitats that experiences extreme changes in temperature, light and salinity. Some groups, such as the

Trentepohliales Trentepohliales is an order of Ulvophyceaen green algae.See the NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH ...

are exclusively found on land. Several species of Chlorophyta live in symbiosis with a diverse range of

eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bact ...

s, including

fungi A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified ...

(to form lichens),

ciliate The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to eukaryotic flagella, but are in general shorter and present in much larger numbers, with a differen ...

s, forams,

cnidarian Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in Fresh water, freshwater and Marine habitats, marine environments, predominantly the latter. Their distinguishing feature is cnidocyt ...

s and molluscs. Some species of Chlorophyta are

heterotrophic A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

, either free-living or

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

. Others are

mixotroph A mixotroph is an organism that can use a mix of different Primary nutritional groups, sources of energy and carbon, instead of having a single trophic mode on the continuum from complete autotrophy at one end to heterotrophy at the other. It is est ...

bacterivore A bacterivore is an organism which obtains energy and nutrients primarily or entirely from the consumption of bacteria. The term is most commonly used to describe free-living, heterotrophic, microscopic organisms such as nematodes as well as many s ...

s through

phagocytosis Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis i ...

. Two common species of the heterotrophic green alga ''

Prototheca ''Prototheca'' is a genus of algae in the family Chlorellaceae. All the species within this genus, even though classified as green algae, have forfeited their photosynthetic ability and have switched to parasitism. Some species can cause the dis ...

'' are

pathogenic In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a ger ...

and can cause the disease protothecosis in humans and animals.

Classifications

Characteristics used for the classification of Chlorophyta are: type of zoid,

mitosis In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maint ...

(karyokynesis),

cytokinesis Cytokinesis () is the part of the cell division process during which the cytoplasm of a single eukaryotic cell divides into two daughter cells. Cytoplasmic division begins during or after the late stages of nuclear division in mitosis and me ...

, organization level,

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia * Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring * Life-cycle hypothesi ...

, type of

gametes A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce ...

cell wall A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mec ...

polysaccharides Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with w ...

and more recently

genetic data In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding gen ...

Phylogeny

A newer proposed classification follows Leliaert et al. 2011 and modified with Silar 2016, Leliaert 2016 and Lopes dos Santos et al. 2017 for the green algal clades and Novíkov & Barabaš-Krasni 2015 for the land plants clade. Sánchez-Baracaldo et al. is followed for the basal clades. A 2020 paper places the "Prasinodermophyta" (i.e. Prasinodermophyceae +

) as the basal Viridiplantae clade.

Leliaert ''et al''. 2012

Simplified phylogeny of the Chlorophyta, according to Leliaert ''et al''. 2012. Note that many algae previously classified in Chlorophyta are placed here in Streptophyta. *

**Chlorophyta ***core chlorophytes ****

*****

Cladophorales Cladophorales are an order of green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryoph ...

*****

Dasycladales Dasycladales is an order of large unicellular green algae in the class Ulvophyceae. It contains two families, the Dasycladaceae and the Polyphysaceae. These single celled algae are from 2 mm to 200 mm long. They live on substrates ...

*****

Bryopsidales Bryopsidales is an order of green algae, in the class Ulvophyceae. Characteristics The thallus is filamentous and much branched and may be packed into a mass. It is coenocytic, having multi-nucleate cells consisting of cytoplasm contained with ...

*****

Ulvales Ulvales is an order of green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) ha ...

Ulotrichales Ulotrichales is an order of green algae in the class Ulvophyceae.See the NCBIbr>webpage on Ulotrichales Data extracted from the Genera unplaced to family (''incertae sedis''): *''Trichosarcina ''Trichosarcina'' is a genus of green algae in ...

*****

Oltmannsiellopsidales Oltmannsiellopsidales is an order of green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryo ...

****

***** Oedogoniales *****

Chaetophorales Chaetophorales is an order of green algae in the class Chlorophyceae. Families * '' Aphanochaetaceae'' Oltmanns * '' Barrancaceae'' Caisová et al. * ''Chaetophoraceae Chaetophoraceae is a family of green algae in the order Chaetophora ...

***** Chaetopeltidales *****

Chlamydomonadales Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae.See the NCBIbr>webpage on Chlamydomonadales Data extracted from the Chlamydomonadales can form planar or ...

*****

Sphaeropleales Sphaeropleales is an order of green algae that used to be called Chlorococcales. The order includes some of the most common freshwater planktonic algae such as '' Scenedesmus'' and '' Pediastrum''. The Spaeropleales includes vegetatively non-mot ...

****

*****

Chlorellales The Chlorellales are an order of green algae in the class Trebouxiophyceae.See the NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Insti ...

*****

Oocystaceae Oocystaceae is a family of green algae, in the order Chlorellales. The type genus is '' Oocystis''. List of genera , AlgaeBase accepted the following genera: *'' Amphikrikos'' Korshikov – 6 species *'' Catenocystis'' F.Hindák – 2 species * ...

*****

Microthamniales Microthamniaceae is a family of green algae in the class Trebouxiophyceae.See the NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institu ...

***** Trebouxiales *****'' Prasiola'' clade ****

Chlorodendrophyceae Chlorodendrales are an order of green, flagellated, thecate, unicellular eukaryotes, within the green algae class Chlorodendrophyceae.Becker, B., Marin, B. and Melkonian, M. 1994: Structure, composition, and biogenesis of prasinophyte cell coveri ...

***

prasinophyte The prasinophytes are a group of unicellular green algae. Prasinophytes mainly include marine planktonic species, as well as some freshwater representatives.Sym, S. D. and Pienaar, R. N. 1993. The class Prasinophyceae. In Round, F. E. and Chapman ...

s (paraphyletic) ****

Pyramimonadales Pyramimonadales are an order of green algae in the Chlorophyta. The chloroplasts of phototrophic euglenids probably came from endosymbiosis with a member of this order. Taxonomy * Family Polyblepharidaceae Dangeard 1888 ** Genus '' Amphoraemona ...

****

Mamiellophyceae Mamiellophyceae is a class of green algae in the division Chlorophyta Chlorophyta or Prasinophyta is a taxon of green algae informally called chlorophytes. The name is used in two very different senses, so care is needed to determine the us ...

****

Pycnococcaceae Pycnococcaceae is a family of green algae in the order Pseudoscourfieldiales. The defining features of this family include the single invagination of the pyrenoid where the mitochondrial membrane fits into it Guillard ''et al.'' 1991 Pycnococcu ...

**** Nephroselmidophyceae ****

Prasinococcales Prasinococcaceae is a family of green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryo ...

****

Palmophyllales The Palmophyllales are a deep-branching order of thalloid green alga, possibly forming a sister group to the Chlorophyta. They survive today in deep waters, where predation pressure is reduced. The group contains the genera ''Palmophyllum'', '' ...

Streptophyta Streptophyta (), informally the streptophytes (, from the Greek ''strepto'' 'twisted', for the morphology of the sperm of some members), is a clade of plants. The composition of the clade varies considerably between authors, but the definition ...

***

charophyte Charophyta () is a group of freshwater green algae, called charophytes (), sometimes treated as a division, yet also as a superdivision or an unranked clade. The terrestrial plants, the Embryophyta emerged within Charophyta, possibly from terr ...

s ****

Mesostigmatophyceae The Mesostigmatophyceae are a class of basal green algae found in freshwater. In a narrow circumscription, the class contains a single genus, '' Mesostigma''. AlgaeBase then places the order within its circumscription of Charophyta. A clade conta ...

****

Chlorokybophyceae ''Chlorokybus'' is a multicellular (sarcinoid) genus of basal green algae or charophyte, a soil alga Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a pol ...

****

Klebsormidiophyceae Klebsormidiales is an order of charophyte algae. It is the only order in the class Klebsormidiophyceae, sister of the Phragmoplastophyta. , AlgaeBase accepted two families in the order: * Elakatotrichaceae Hindák *Klebsormidiaceae The Klebsorm ...

****

Charophyceae Charophyceae is a class of charophyte green algae. AlgaeBase places it in division Charophyta. Extant (living) species are placed in a single order Charales, commonly known as "stoneworts" and "brittleworts". Fossil members of the class may be ...

****

Zygnematophyceae Zygnematophyceae (or Conjugatophyceae) is a class of green algae in the paraphylum streptophyte algae, also referred to as Charophyta, consisting of more than 4000 described species. It contains five orders: the Spirogloeales, the Serritaeniales, ...

****

Coleochaetophyceae Coleochaetophyceae are a class of charophyte algae that includes some of the closest multicellular relatives of land plants The Embryophyta (), or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embr ...

***

(land plants)

Pombert ''et al''. 2005

A possible classification when Chlorophyta refers to one of the two clades of the Viridiplantae is shown below. * Class

Prasinophyceae The prasinophytes are a group of unicellular green algae. Prasinophytes mainly include marine planktonic species, as well as some freshwater representatives.Sym, S. D. and Pienaar, R. N. 1993. The class Prasinophyceae. In Round, F. E. and Chapman ...

T. A. Chr. ex Ø. Moestrup & J. Throndsen * Class

Wille * Class

T. Friedl * Class

Lewis & McCourt 2004

* Division Chlorophyta (green algae sensu stricto) ** Subdivision Chlorophytina *** Class

(chlorophytes) **** Order

(+ some Chlorococcales + some

Tetrasporales The Tetrasporales are a formerly recognized order of green algae, specifically the Chlorophyceae, now included in Chlamydomonadales. AlgaeBase AlgaeBase is a global species database of information on all groups of algae, both marine and fres ...

+ some Chlorosarcinales) **** Order

(sensu Deason, plus ''Bracteacoccus, Schroederia, Scenedesmaceae, Selanastraceae'') **** Order Oedogoniales **** Order Chaetopeltidales **** Order

**** Incertae Sedis (''Cylindrocapsa'' clade, ''Mychonastes'' clade) *** Class

(ulvophytes) **** Order

**** Order

**** Order Siphoncladales/

**** Order Caulerpales **** Order

*** Class

(trebouxiophytes) **** Order Trebouxiales **** Order

**** Order Prasiolales **** Order

*** Class

(prasinophytes) **** Order

**** Order

Mamiellales Mamiellales are an order of green algae in the class Mamiellophyceae. Their cells and flagella are covered with spiderweb-like scales of several types. Some species lack scales but possess pigments similar to those of the scale-bearing species. ...

**** Order Pseudoscourfieldiales **** Order

Chlorodendrales Chlorodendrales are an order of green, flagellated, thecate, unicellular eukaryotes, within the green algae class Chlorodendrophyceae.Becker, B., Marin, B. and Melkonian, M. 1994: Structure, composition, and biogenesis of prasinophyte cell cover ...

**** Incertae sedis (Unnamed clade of coccoid taxa) * Division

(charophyte algae and embryophytes) ** Class

(mesostigmatophytes) ** Class

(chlorokybophytes) ** Class

(klebsormidiophytes) ** Class

Zygnemophyceae Zygnematophyceae (or Conjugatophyceae) is a class of green algae in the paraphylum streptophyte algae, also referred to as Charophyta, consisting of more than 4000 described species. It contains five orders: the Spirogloeales, the Serritaeniales, ...

(conjugates) *** Order Zygnematales (filamentous conjugates and saccoderm desmids) *** Order

Desmidiales Desmidiales, commonly called desmids (''Gr.'' ''desmos'', bond or chain), are an order in the Charophyta, a division of green algae in which the land plants (Embryophyta) emerged. Or in other words, Desmid, (order Desmidiales), order of single- ...

(placoderm desmids) ** Class

(coleochaetophytes) *** Order Coleochaetales ** Subdivision

Streptophytina The Phragmoplastophyta (Lecointre & Guyader 2006) are a proposed sister clade of the Klebsormidiaceae in the Streptophyte/Charophyte clade. The Phragmoplastophyta consist of the Charophycaea and another unnamed clade which contains the Coleocha ...

*** Class

(reverts to use of GM Smith) **** Order

Charales Charales is an order of freshwater green algae in the division Charophyta, class Charophyceae, commonly known as stoneworts. Depending on the treatment of the genus '' Nitellopsis'', living (extant) species are placed into either one family (C ...

(charophytes sensu stricto) *** Class Embryophyceae (embryophytes)

Hoek, Mann and Jahns 1995

Classification of the Chlorophyta, treated as all green algae, according to Hoek, Mann and Jahns 1995. * Class

(orders

, Pseudocourfeldiales,

) * Class

(orders

Volvocales Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae.See the NCBIbr>webpage on Chlamydomonadales Data extracted from the Chlamydomonadales can form planar or ...

[including the

], Chlorococcales,

, Oedogoniales) * Class

(orders Codiolales,

) * Class Cladophorophyceae (order

) * Class

Bryopsidophyceae Bryopsidophyceae is an unaccepted class of chlorophyte green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The ...

(orders

, Halimedales) * Class Dasycladophyceae (order

) * Class Trentepohliophyceae (order

) * Class Pleurastrophyceae (order Pleurastrales) * ''

Incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

'' (order Prasiolales) * Class

(orders

Klebsormidiales Klebsormidiales is an order of charophyte algae. It is the only order in the class Klebsormidiophyceae, sister of the Phragmoplastophyta. , AlgaeBase AlgaeBase is a global species database of information on all groups of algae, both marine ...

, Coleochaetales) * Class

(order Zygnematales,

) * Class

(order

) In a note added in proof, an alternative classification is presented for the algae of the class Chlorophyceae: * Class Chlamydophyceae (orders

, Chlorococcales,

) * Class Oedogoniophyceae (order Oedogoniales) * Class

(order

)

Bold and Wynne 1985

Classification of the Chlorophyta and Charophyta according to Bold and Wynne 1985. * Chlorophyta,

(16 orders) **

** Chlorococcales ** Chlorosarcinales **

** Oedogoniales **

** Acrosiphoniales ** Caulerpales ** Siphonocladales **

** Zygnematales *

(1 order) **

Mattox & Stewart 1984

Classification of the Chlorophyta according to Mattox & Stewart 1984: * Micromonadophyceae (similar to

; Tetraselmidiales transferred to Pleurastrophyceae) *

Rabenhorst **

Chlorokybales ''Chlorokybus'' is a multicellular (sarcinoid) genus of basal green algae or charophyte, a soil alga Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a pol ...

** Zygnematales ** Coleochaetales **

* Pleurastrophyceae ** Tetraselmidiales ** Pleurastrales *

Wille in Warming **

** Chlorococcales **

** Chlorosarcinales **

** Oedogoniales

Fott 1971

Classification of the Chlorophyta according to Fott 1971. *Class

:*Order

:*Order Chlorococcales :*Order

::*Suborder Chlorosarcineae ::*Suborder Ulotrichineae ::*Suborder Oedogoniineae ::*Suborder Chaetophorineae :*Order Siphonocladales :*Order

*Class Conjugatophyceae *Class

Round 1971

Classification of the Chlorophyta and related algae according to Round 1971. * "

" ** Euglenophyta ** Prasinophyta **

** Chlorophyta ***

Zygnemaphyceae Zygnematophyceae (or Conjugatophyceae) is a class of green algae in the paraphylum streptophyte algae, also referred to as Charophyta, consisting of more than 4000 described species. It contains five orders: the Spirogloeales, the Serritaeniales, ...

(= Conjugatophyceae; orders Mesotaeniales, Zygnematales, Gonatozygales,

) *** Oedogoniophyceae (order Oedogoniales) ***

**** Hemisiphoniidae (orders

, Acrosiphoniales **** Cystosiphoniidae (orders

, Siphonocladales, Chlorochytriales) **** Eusiphoniidae (orders Derbesiales, Codiales, Caulerpales, Dichotomosiphonales, Phyllosiphonales) ***

**** orders

, Polyblepharidales,

, Chlorosarcinales, Chlorococcales **** orders

, Codiolales,

, Prasiolales, Cylindrocapsales, Microsporales **** orders

, Coleochaetales,

, Pleurococcales, Ulvellales

Smith 1938

Classification of the Chlorophyta according to

Smith Smith may refer to: People * Metalsmith, or simply smith, a craftsman fashioning tools or works of art out of various metals * Smith (given name) * Smith (surname), a family name originating in England, Scotland and Ireland ** List of people w ...

1938: *Class 1.

::*Order 1.

::::*Family 1.

Chlamydomonadaceae Chlamydomonadaceae is a family of algae within the order Chlamydomonadales.See the NCBIbr>webpage on Chlamydomonadaceae Data extracted from the Genera As accepted by WoRMS; * '' Agloë'' * '' Brachiomonas'' * '' Carteria'' * '' Cercidium' ...

::::*Family 2.

Volvocaceae The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus ''Volvox''. The family was named by Ehrenberg in 1834,From p. 281: ''"VOLVOCINA Nova Familia."'' (Volvocina New Family.) ote: According to p. 1 ...

::*Order 2.

::*Order 3.

::::*Family 1.

Ulotrichaceae Ulotrichaceae is a family of green algae in the order Ulotrichales Ulotrichales is an order of green algae in the class Ulvophyceae.See the NCBIbr>webpage on Ulotrichales Data extracted from the Genera unplaced to family (''incertae sedis' ...

::::*Family 2. Microsporaceae ::::*Family 3. Cylindrocapsaceae ::::*Family 4.

Chaetophoraceae Chaetophoraceae is a family of green algae in the order Chaetophorales. Genera * ''Arthrochaete'' * '' Caespitella'' * ''Cedercreutziella'' * ''Chaetomnion'' * ''Chaetonemopsis'' * '' Chaetophora'' * '' Chloroclonium'' * '' Chlorofilum'' * ' ...

::::*Family 5. Protococcaceae ::::*Family 6.

Coleochaetaceae Coleochaetaceae is a family of algae. It is the only family in the Coleochaetales, an order of parenchymous charophyte algae, that includes some of the closest multicellular relatives of land plants. They questionably include the fossil genus ...

::::*Family 7.

Trentepohliaceae Trentepohliaceae are a 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 ...

::*Order 4.

::::*Family 1.

Ulvaceae Ulvaceae () is a widely distributed family of thin green algae having either a flat or a hollow tubular thallus, reproducing by the conjugation of planogametes or of zoospores, and being classed among the Ulotrichales or now more commonly placed ...

::::*Family 2

Schizomeridaceae Schizomeridaceae is a family of algae in the order Chaetophorales Chaetophorales is an order of green algae in the class Chlorophyceae. Families * '' Aphanochaetaceae'' Oltmanns * '' Barrancaceae'' Caisová et al. * ''Chaetophoraceae ...

::*Order 5. Schizogoniales ::::*Family Schizogoniaceae ::*Order 6.

::::*Family 1.

Cladophoraceae Cladophoraceae are a family of green algae in the order the Cladophorales.See the NCBIbr>webpage on Cladophoraceae Data extracted from the This family includes notably the genus ''Chaetomorpha ''Chaetomorpha'' is a genus of green algae in ...

::::*Family 2. Sphaeropleaceae ::*Order 7. Oedogoniales ::::*Family Oedogoniaceae ::*Order 8. Zygnematales ::::*Family 1. Zygnemataceae ::::*Family 2.

Mesotaeniaceae The Mesotaeniaceae are a small family of unicellular green algae known as the "saccoderm desmids". The Mesotaeniaceae appear to be sister or ancestral to the Zygnemataceae. The desmids are a deep branching group of Zygnemataceae. ''Spirotaenia ...

::::*Family 3.

Desmidiaceae The Desmidiaceae are one of four families of charophyte green algae in the order Desmidiales (desmids).See the NCBIbr>webpage on Desmidiaceae Data extracted from the Genera Genera accepted by AlgaeBase were: *'' Actinodontum'' – 3 spe ...

::*Order 9. Chlorococcales ::::*Family 1.

Chlorococcaceae Chlorococcaceae is a family of green algae, in the order Chlamydomonadales. List of genera * ''Apodochloris'' * ''Bracteacoccus'' * ''Chlorococcopsis'' * ''Chlorococcum'' * ''Chlorohippotes'' * ''Chlorotetraedron'' * ''Closteridium'' * ''Cocco ...

::::*Family 2. Endosphaeraceae ::::*Family 3. Characiaceae ::::*Family 4. Protosiphonaceae ::::*Family 5.

Hydrodictyaceae Hydrodictyaceae is a family of green algae in the order Sphaeropleales. Genera * ''Euastropsis'' * '' Helierella'' * ''Hydrodictyon'' * '' Lacunastrum'' * ''Monactinus'' * ''Parapediastrum'' * '' Pediastrum'' * ''Pseudopediastrum'' * ''Sorastr ...

::::*Family 6. Oöcystaceae ::::*Family 7.

Scenedesmaceae Scenedesmaceae is a family of green algae in the order Sphaeropleales. ''Scenedesmus'' algae are commonly found in freshwater plankton. The former family Coelastraceae is considered a synonym of Scenedesmaceae. Genera Genera in this family ...

::*Order 10. Siphonales ::::*Family 1.

Bryopsidaceae Bryopsidaceae is a family of green algae, in the order Bryopsidales Bryopsidales is an order of green algae, in the class Ulvophyceae. Characteristics The thallus is filamentous and much branched and may be packed into a mass. It is coenocy ...

::::*Family 2.

Caulerpaceae Caulerpaceae is a family of green algae in the order Bryopsidales Bryopsidales is an order of green algae, in the class Ulvophyceae. Characteristics The thallus is filamentous and much branched and may be packed into a mass. It is coenocyti ...

::::*Family 3. Halicystaceae ::::*Family 4.

Codiaceae Codiaceae is a family of green algae in the order Bryopsidales. Genera * † '' Abacella'' Maslov * '' Appeninocodium'' O.Dragastan * '' Arabicodium'' G.F.Elliott * '' Bevocastria'' E.J.Garwood * '' Botryella'' V.P.Shuysky * '' Boueina'' F ...

::::*Family 5.

Derbesiaceae Derbesiaceae are a family of green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) ...

::::*Family 6. Vaucheriaceae ::::*Family 7. Phyllosiphonaceae ::*Order 11. Siphonocladiales ::::*Family 1. Valoniaceae ::::*Family 2.

Dasycladaceae The Dasycladaceae is one of the two extant families of green algae of the order Dasycladales. When found in Palaeozoic limestones, they typically indicate depositional depth of less than 5m.See the NCBIbr>webpage on Dasycladaceae Data extract ...

*Class 2.

::*Order

::::*Family

Characeae Characeae is a family of freshwater green algae in the order Charales, commonly known as stoneworts. They are also known as brittleworts or skunkweed, from the fragility of their lime-encrusted stems, and from the foul odor these produce when step ...

Research and discoveries

In February 2020, the fossilized remains of green algae, named ''Proterocladus antiquus'' were discovered in the northern province of Liaoning, China. At around a billion years old, it is believed to be one of the oldest examples of a multicellular chlorophyte.

Ecology

Classifications

Phylogeny

Leliaert ''et al''. 2012

Pombert ''et al''. 2005

Lewis & McCourt 2004

Hoek, Mann and Jahns 1995

Bold and Wynne 1985

Mattox & Stewart 1984

Fott 1971

Round 1971

Smith 1938

Research and discoveries

References

Further reading