The Hoek, Mann and Jahns system is a system of taxonomy of algae. It was first published in ''Algae: An Introduction to Phycology'' by Cambridge University Press in 1995.

Division Cyanophyta (= Cyanobacteria)

* Class

Cyanophyceae Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue ...

:* Order

Chroococcales The Chroococcales () are an order of cyanobacteria in some classifications which includes the harmful algal bloom ''Microcystis aeruginosa''. Molecular data indicate that Chroococcales may be polyphyletic, meaning its members may not all belong ...

(e.g., ''

Cyanothece ''Cyanothece'' is a genus of unicellular, diazotrophic, oxygenic photosynthesizing cyanobacteria. Modern organisms and cellular organization In 1976, Jiří Komárek defined the prokaryotic cyanobacteria genus ''Cyanothece'' as distinct from ' ...

Aphanothece ''Aphanothece'' is a genus of cyanobacteria belonging to the family Aphanothecaceae. The genus has cosmopolitan distribution. Species: *'' Aphanothece atro-crustacea'' *'' Aphanothece bullosa'' *'' Aphanothece castagnei'' References { ...

Merismopedia ''Merismopedia'' (from the Greek ''merismos'' ivisionand the Greek ''pedion'' lain is a genus of cyanobacteria found in fresh and salt water. It is ovoid or spherical in shape and arranged in rows and flats, forming rectangular colonies held t ...

, Chroococcus,

Gloeocapsa ''Gloeocapsa'' (from the Greek ''gloia'' (gelatinous) and the Latin ''capsa'' (case)) is a genus of cyanobacteria. The cells secrete individual gelatinous sheaths which can often be seen as sheaths around recently divided cells within outer shea ...

Microcystis ''Microcystis'' is a genus of freshwater cyanobacteria that includes the harmful algal bloom-forming ''Microcystis aeruginosa''. Many members of a ''Microcystis'' community can produce neurotoxins and hepatotoxins, such as microcystin and cyan ...

, Chamaesiphon'') :* Order

Pleurocapsales The Pleurocapsales are an order of coccooid cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which ...

(e.g., '' Cyanocystis, Pleurocapsa'') :* Order

Oscillatoriales The Oscillatoriales are an order of cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similar ...

(e.g., ''

Oscillatoria ''Oscillatoria'' is a genus of filamentous cyanobacterium which is often found in freshwater environments, such as hot springs, and appears blue-green. Its name refers to the oscillating motion of its filaments as they slide against each other ...

Lyngbya ''Lyngbya'' is a genus of cyanobacteria, unicellular autotrophs that form the basis of the oceanic food chain. As a result of recent genetic analyses, several new genera were erected from this genus: ''e.g.'', ''Moorea'', '' Limnoraphis'', '' O ...

, Microcoleus'') :* Order

Nostocales The Nostocales are an order of cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly f ...

(e.g., ''

Nostoc ''Nostoc'', also known as star jelly, troll’s butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch’s jelly, is the most common genus of cyanobacteria found in var ...

Anabaena ''Anabaena'' is a genus of filamentous cyanobacteria that exist as plankton. They are known for nitrogen-fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanob ...

, Aphanizomenon,

Scytonema ''Scytonema'' is a genus of photosynthetic cyanobacteria that contains over 100 species. It grows in filaments that form dark mats. Many species are aquatic and are either free-floating or grow attached to a submerged substrate, while others s ...

, Rivularia'') :* Order

Stigonematales The Rivulariaceae are a family of cyanobacteria within the Nostocales in which the filaments (trichomes) are tapered from wider at the base to narrower at the tip. The type species is '' Rivularia haematites'' (Dc) C. A. Agardh. Genera , Wo ...

(e.g., '' Stigonema'')

Division Prochlorophyta

* Class Prochlorophyceae (e.g., ''

Prochloron ''Prochloron'' (from the Greek ''pro'' (before) and the Greek ''chloros'' (green) ) is a genus of unicellular oxygenic photosynthetic prokaryotes commonly found as an extracellular symbiont on coral reefs, particularly in didemnid ascidians (sea ...

Prochlorococcus ''Prochlorococcus'' is a genus of very small (0.6 μm) marine cyanobacteria with an unusual pigmentation ( chlorophyll ''a2'' and ''b2''). These bacteria belong to the photosynthetic picoplankton and are probably the most abundant photosynth ...

Prochlorothrix Prochlorophyta is a group of photosynthetic bacteria, an important component of picoplankton. These oligotrophic organisms are abundant in nutrient poor tropical waters and use a unique photosynthetic pigment, divinyl-chlorophyll, to absorb light ...

'')

Division Glaucophyta

* Class Glaucophyceae (e.g., '' Cyanophora, Glaucocystis'')

Division Rhodophyta

* Class

Bangiophyceae Bangiophyceae is a class of red algae. In some classifications it is merged with the Florideophyceae to form the Rhodophyceae. The Bangiophyceae, as defined traditionally, are paraphyletic. Their Taxonomy (biology), taxonomic identification h ...

:* Order Porphyridiales (e.g., '' Porphyridium, Chroodactylon'') :* Order Rhodochaetales (e.g., '' Rhodochaete'') :* Order Erythropeltidales (e.g., '' Erythrotrichia'') :* Order Compsogonales :* Order

Bangiales Bangiales is an order of red algae in the class Bangiophyceae. References {{Taxonbar, from=Q2715035 Red algae orders Bangiophyceae ...

(e.g., ''

Porphyra ''Porphyra'' is a genus of coldwater seaweeds that grow in cold, shallow seawater. More specifically, it belongs to red algae phylum of laver species (from which comes laverbread), comprising approximately 70 species.Brodie, J.A. and Irvine, ...

Bangia ''Bangia'' is an extant genus of division Rhodophyta that grows in marine or freshwater habitats. ''Bangia'' has small thalli with rapid growth and high reproductive output, and exhibits behavior characteristic of r-selected species. The plants ...

'') * Class

Florideophyceae Florideophyceae is a class of red algae. They were once thought to be the only algae to bear pit connections, but these have since been found in the filamentous stage of the Bangiaceae. They were also thought only to exhibit apical growth, but t ...

:* Order

Acrochaetiales Acrochaetiales is an order of red algae. Taxonomy Acrochaetiales contains two families and six genera: * Acrochaetiaceae Fritsch ex W.R.Taylor **'' Acrochaetium'' Nägeli (synonyms: ''Chromastrum'' Papenfuss, ''Kylinia'' Rosenvinge, ''Liago ...

(e.g., ''

Audouinella ''Audouinella'', also known as black algae, is a widespread genus of red algae, found in marine and freshwater environments. The form known as "''black brush algae''" (or "''black beard algae''", ''BBA'' for short) is a particular nuisance in a ...

'') :* Order Palmariales (e.g., '' Palmaria, Rhodophysema'') :* Order Nemaliales (e.g., '' Nemalion, Galaxaura'') :* Order Batrachospermales (e.g., '' Lemanea, Batrachospermum'') :* Order Corallinales (e.g., '' Lithophyllum, Jania'') :* Order Hildebrandiales :* Order Bonnemaisoniales :* Order Gelidiales (e.g., ''

Gelidium ''Gelidium'' is a genus of thalloid red algae comprising 134 species. Its members are known by a number of common names.Recorded common names are tengusa, makusa, genso, niu mau tsai, japansche scheleiachtige mos, steen-or klipbloem, hay tsay, ol ...

'') :* Order

Gigartinales Gigartinales is a red algae order in the class Florideophyceae Florideophyceae is a class of red algae. They were once thought to be the only algae to bear pit connections, but these have since been found in the filamentous stage of the Bang ...

(e.g., '' Acrosymphyton, Dumontia, Chondrus, Mastocarpus'') :* Order Gracilariales :* Order Ahnfeltiales :* Order Rhodymeniales (e.g., '' Chylocladia'') :* Order

Ceramiales Ceramiales is an order of red algae. It was established by Friedrich Oltmanns in 1904. Families * Callithamniaceae Kützing, 1843 * Ceramiaceae Dumortier, 1822 * Choreocolacaceae Sturch * Dasyaceae Kützing, 1843 * Delesseriaceae Bory, ...

(e.g., ''

Polysiphonia ''Polysiphonia'' is a genus of filamentous red algae with about 19 species on the coasts of the British Isles and about 200 species worldwide, including Crete in Greece, Antarctica and Greenland. Its members are known by a number of common names ...

, Callithamnion, Ceramium, Hypoglossum'')

Division Heterokontophyta

* Class

Chrysophyceae The Chrysophyceae, usually called chrysophytes, chrysomonads, golden-brown algae or golden algae are a large group of algae, found mostly in freshwater. Golden algae is also commonly used to refer to a single species, '' Prymnesium parvum'', whic ...

:* Order Ochromonadales (e.g., ''

Ochromonas ''Ochromonas'' is a genus of algae belonging to the family Chromulinaceae. The genus has cosmopolitan distribution. Chlorosulfolipids, a class of biologically active compounds, was first discovered in some ''Ochromonas'' species. Species A ...

, Pseudokephyrion,

Dinobryon ''Dinobryon'' is a type of microscopic algae. It is one of the 22 genera in the family Dinobryaceae. ''Dinobryon'' are mixotrophs, capable of obtaining energy and carbon through photosynthesis and phagotrophy of bacteria. The genus comprises at ...

'') :* Order Mallomonadales (= Class Synurophyceae, e.g., ''

Mallomonas ''Mallomonas'' is a genus comprising unicellular algal eukaryotes and characterized by their intricate cell coverings made of silica scales and bristles. The group was first named and classified by Dr. Maximilian Perty in 1852. These organisms l ...

Synura ''Synura'' is a genus of colonial chrysomonad algae covered in silica scales. It is the most conspicuous genus of the order Synurales The synurids (order Synurales) are a small group of heterokont algae, found mostly in freshwater environments ...

'') :* Order

Pedinellales Pedinellales is a group of single-celled algae found in both marine environments and freshwater. These are found in both freshwater and marine environments, and most genera are sessile, attached by posterior stalks. The flagellum is at the ant ...

(= Class Pedinellophyceae, e.g., ''

Pedinella ''Pedinella'' is a genus of small, unicellular planktonic or attached, flagellated heterokonts first described in 1888 by A. V. Vysotskij. The genus is monospecific, and the single species is ''Pedinella hexacostata'' Vysotskij. ''Pedinella'' ha ...

'') :* Order Chrysamoebidales (e.g., '' Rhizochrysis, Chrysarachnion'') :* Order Chrysocapsales (e.g., '' Chrysocapsa, Hydrurus'') :* Order Chrysosphaerales (e.g., '' Chrysosphaera'') :* Order Phaeothamniales (e.g., '' Phaeothamnion, Thallochrysis'') * Class Parmophyceae :* Order

Parmales The Parmales are an order of marine microalgae within the Bolidophyceae class. They are found worldwide and characterized by a cell wall composed of 5-8 interlocking silica plates with distinct forms. They were initially thought to be loricate ch ...

(e.g., '' Pentalamina'') * Class Sarcinochrysidophyceae :* Order Sarcinochrysidales (e.g., '' Ankylochrysis, Sarcinochrysis, Nematochrysis'') * Genus '' Pelagococcus'' (relative of the Chrysophyceae) * Class

Xanthophyceae Yellow-green algae or the Xanthophyceae (xanthophytes) are an important group of heterokont algae. Most live in fresh water, but some are found in marine and soil habitats. They vary from single-celled flagellates to simple colonial and filamen ...

:* Order Chloramoebales (e.g., '' Chloromeson'') :* Order Rhizochloridales (e.g., '' Rhizochloris, Myxochloris'') :* Order Heterogloeales (e.g., '' Gloeochloris'') :* Order Mischococcales (e.g., '' Chloridella, Botrydiopsis, Characiopsis, Ophiocytium'') :* Order Tribonematales (e.g., '' Tribonema, Heterococcus, Heterodendron'') :* Order Botrydiales (e.g., '' Botrydium'') :* Order Vaucheriales (e.g., '' Vaucheria'') * Class

Eustigmatophyceae Eustigmatophytes are a small group (17 genera; ~107 species) of eukaryotic forms of algae that includes marine, freshwater and soil-living species. All eustigmatophytes are unicellular, with coccoid cells and polysaccharide cell walls. Eust ...

(e.g., '' Ellipsoidion, Eustigmatos _Pleurochloris.html" ;"title="Pleurochloris.html" ;"title=" Pleurochloris"> Pleurochloris">Pleurochloris.html" ;"title=" Pleurochloris"> Pleurochloris Polyedriella, Vischeria, Chlorobotrys, Nannochloropsis'') * Class Bacillariophyceae (= Diatomophyceae) :* Order Pennales (e.g., ''Navicula, Gyrosigma, Achnanthes, Tabellaria,

Nitzchia ''Nitzschia'' is a common pennate marine diatom. In the scientific literature, this genus, named after Christian Ludwig Nitzsch, is sometimes termed ''Nitzchia'', and it has many species described, which all have a similar morphology. Occurrenc ...

, Surirella'') :* Order Centrales (e.g., '' Coscinodiscus,

Thalassiosira ''Thalassiosira'' is a genus of centric diatoms, comprising over 100 marine and freshwater species. It is a diverse group of photosynthetic eukaryotes that make up a vital part of marine and freshwater ecosystems, in which they are key primary pr ...

, Stephanodiscus, Cerataulus, Triceratium, Odontella, Rhizosolenia'') * Class Raphidophyceae (e.g., '' Chatonella, Gonyostomum, Merotrichia, Vacuolaria, Fibrocapsa'') * Class

Dictyochophyceae Dictyochophyceae sensu lato is a photosynthetic lineage of heterokont algae. Taxonomy * Class Dictyochophyceae Silva 1980 s.l. ** Subclass Sulcophycidae Cavalier-Smith 2013 *** Order Olisthodiscales Cavalier-Smith 2013 **** Family Olisthodis ...

(e.g., ''

Dictyocha Dictyochales (Silicoflagellates, or Dictyochophyceae '' sensu stricto'') are a small group of unicellular heterokont algae, found in marine environments. Characteristics In one stage of their life cycle, they produce a siliceous skeleton, co ...

'') * Class Phaeophyceae :* Order Ectocarpales (e.g., '' Phaeostroma, Spongonema, Ectocarpus'') :* Order Sphacelariales (e.g., '' Sphacelaria'') :* Order Syringodermatales :* Order

Dictyotales Dictyotales is a large order in the brown algae (class Phaeophyceae). Members of this order generally prefer warmer waters than other brown algae. One genus in this order is calcareous, '' Padina'', the only calcareous member of this phylum. ' ...

(e.g., ''

Dictyota ''Dictyota'' is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of ...

'') :* Order Scytosiphonales (e.g., '' Scytosiphon'') :* Order

Cutleriales Tilopteridales is an order of brown algae Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae ...

(e.g., '' Cutleria'') :* Order Dictyosiphonales (e.g., '' Dictyosiphon'') :* Order Chordariales (e.g., '' Sphaerotrichia'', '' Liebmania'', '' Elachista'') :* Order Sporochnales :* Order

Desmarestiales Desmarestiales is an order in the brown algae (Phaeophyceae). Members of this order have terete or ligulate (flat) pinnately branched thalli attached by discoid holdfasts. They have a sporphytic thallus usually aggregated to form a pseudo-par ...

(e.g., ''

Desmarestia ''Desmarestia'' is a genus of brown algae found worldwide. It is also called acid weed, acidweed, ', sea sorrel, (), ', mermaid's hair, landlady's wig, or '. However, 'sea sorrel' can also specifically refer to '' Desmarestia viridis''. Mem ...

'') :* Order Laminariales (e.g., ''

Laminaria ''Laminaria'' is a genus of brown seaweed in the order Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery laminae and relati ...

, Chorda'') :* Order

Fucales The Fucales (fucoids) are an order in the brown algae (class Phaeophyceae). The list of families in the Fucales, as well as additional taxonomic information on algae, is publicly accessible at Algaebaseref name="Guiry and Guiry">Guiry, M.D. and ...

(e.g., ''

Fucus ''Fucus'' is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world. Description and life cycle The thallus is perennial with an irregular or disc-shaped holdfast or with haptera. The erect portion o ...

, Hormosira'') :* Order Durvillaeales (e.g., '' Durvillaea'') :* Order Ascoseirales * Class Bicocoecida (e.g., '' Pseudobodo, Cafeteria'') * Class

Oomycetes Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the result ...

(e.g., ''

Phytophthora ''Phytophthora'' (from Greek (''phytón''), "plant" and (), "destruction"; "the plant-destroyer") is a genus of plant-damaging oomycetes (water molds), whose member species are capable of causing enormous economic losses on crops worldwide, a ...

'') * Class Hyphochytridiomycetes * Class Labyrinthulomycetes

Division Haptophyta (= Prymnesiophyta)

* Class Haptophyceae :* Order Prymnesiales (e.g., ''

Chrysochromulina ''Chrysochromulina'' is a genus of haptophytes. This phytoplankton is distributed globally in brackish and marine waters across approximately 60 known species. All ''Chrysochromulina'' species are phototrophic, however some have been shown to ...

Prymnesium ''Prymnesium'' is a genus of haptophytes, including the species '' Prymnesium parvum''. The genus is a unicellular motile alga. It is ellipsoidal in shape one flagellum is straight and there are two longer ones which enable movement. The name La ...

, Corymbellus,

Phaeocystis ''Phaeocystis'' is a genus of algae belonging to the Prymnesiophyte class and to the larger division of Haptophyta. It is a widespread marine phytoplankton and can function at a wide range of temperatures ( eurythermal) and salinities (euryhali ...

'') :* Order

Isochrysidales Isochrysidales is an order of Haptophyceae The haptophytes, classified either as the Haptophyta, Haptophytina or Prymnesiophyta (named for ''Prymnesium''), are a clade of algae. The names Haptophyceae or Prymnesiophyceae are sometimes used i ...

(e.g., '' Chrysotila, Pleurochrysis'' _''Hymenomonas''.html" ;"title="Hymenomonas.html" ;"title=" ''Hymenomonas"> ''Hymenomonas''">Hymenomonas.html" ;"title=" ''Hymenomonas"> ''Hymenomonas'' :* Order Coccolithophorales (e.g., ''Emiliania (coccolithophore), Emiliania, Syracosphaera, Discosphaera'') :* Order Pavlovales (e.g., ''Pavlova (alga), Pavlova'')

Division Cryptophyta

* Class

Cryptophyceae The cryptophyceae are a class of algae, most of which have plastids. About 220 species are known, and they are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape ...

(e.g., ''

Cryptomonas ''Cryptomonas'' is the name-giving genus of the Cryptomonads established by German biologist Christian Gottfried Ehrenberg in 1831. The algae are common in freshwater habitats and brackish water worldwide and often form blooms in greater depths ...

Chilomonas ''Chilomonas'' is a genus of cryptophytes, including the species '' Chilomonas paramecium''. Chilomonas is a protozoa (heterotroph). Chilomonas is golden brown and has two flagella A flagellum (; ) is a hairlike appendage that protrudes fr ...

, Bjornbergiella'')

Division Dinophyta

* Class

Dinophyceae Dinophyceae is a class of dinoflagellates. Taxonomy * Class Dinophyceae Pascher 1914 eridinea Ehrenberg 1830 stat. nov. Wettstein; Blastodiniphyceae Fensome et al. 1993 orthog. emend.** Order Haplozoonales aplozooidea Poche 1913*** Family Ha ...

:* Order Gymnodiniales (e.g., ''

Gymnodinium ''Gymnodinium'' is a genus of dinoflagellates, a type of marine and freshwater plankton. It is one of the few naked dinoflagellates, or species lacking armor known as cellulosic plates. Since 2000, the species which had been considered to be par ...

Symbiodinium : ''This is about the genus sometimes called Zoox. For the company, see Zoox (company)'' ''Symbiodinium'' is a genus of dinoflagellates that encompasses the largest and most prevalent group of endosymbiotic dinoflagellates known. These unicell ...

, Polykrikos'') :* Order Gloeodiniales (e.g., '' Gloeodinium'') :* Order Thoracosphaerales (e.g., '' Thoracosphaera'') :* Order Phytodiniales (= Dinococcales, e.g., '' Phytodinium'') :* Order Dinotrichales (e.g., '' Dinoclonium'') :* Order Dinamoebidales (e.g., '' Stylodinium, Dinamoebidium'') :* Order

Noctilucales The Noctilucales are an order of marine dinoflagellates. They differ from most others in that the mature cell is diploid and its nucleus does not show a dinokaryotic organization. They show gametic meiosis. Characteristics These cells are very ...

(e.g., ''

Noctiluca ''Noctiluca scintillans'' is a marine species of dinoflagellate that can exist in a green or red form, depending on the pigmentation in its vacuoles. It can be found worldwide, but its geographical distribution varies depending on whether it i ...

'') :* Order Blastodiniales (e.g., '' Blastodinium'') :* Order Syndiniales :* Order

Peridiniales Peridiniales is an order of dinoflagellates. Below is a uncritical list of the families in Peridinales, but molecular phylogenetics circumscribe the group in a stricter sense.Žerdoner Čalasan A, J Kretschmann & M Gottschling (2019): ''They are ...

(e.g., '' Peridinium, Protoperidinium,

Ceratium The genus ''Ceratium'' is restricted to a small number (about 7) of freshwater dinoflagellate species. Previously the genus contained also a large number of marine dinoflagellate species. However, these marine species have now been assigned to ...

, Gonyaulax'') :* Order Dynophysiales (e.g., ''

Dinophysis ''Dinophysis'' is a genus of dinoflagellatesAlgaeBase''Dinophysis'' Ehrenberg, 1839/ref> common in tropical, temperate, coastal and oceanic waters.Hallegraeff, G.M., Lucas, I.A.N. 1988: The marine dinoflagellate genus Dinophysis (Dinophyceae): ph ...

, Triposolenia, Amphisolenia,

Ornithocercus ''Ornithocercus'' is a genus of planktonic dinoflagellate that is known for its complex morphology that features considerable lists growing from its thecal plates, giving an attractive appearance. Discovered in 1883, this genus has a small numbe ...

Histioneis Histioneis is a genus of dinoflagellates. According to the World Register of Marine Species, it contains 86 species. References Further reading Dinoflagellate genera {{dinoflagellate-stub ...

'') :* Order

Prorocentrales The Prorocentrales are a small order of dinoflagellates. They are distinguished by having their two flagella inserted apically, rather than ventrally as in other groups. One flagellum extends forward and the other circles its base, and there are ...

(e.g., ''

Prorocentrum The Prorocentrales are a small order of dinoflagellates. They are distinguished by having their two flagella inserted apically, rather than ventrally as in other groups. One flagellum extends forward and the other circles its base, and there a ...

'')

Division Euglenophyta

* Class Euglenophyceae :* Order

Euglenales Euglenids (euglenoids, or euglenophytes, formally Euglenida/Euglenoida, ICZN, or Euglenophyceae, ICBN) are one of the best-known groups of flagellates, which are excavate eukaryotes of the phylum Euglenophyta and their cell structure is typic ...

(e.g., ''

Euglena ''Euglena'' is a genus of single cell flagellate eukaryotes. It is the best known and most widely studied member of the class Euglenoidea, a diverse group containing some 54 genera and at least 200 species. Species of ''Euglena'' are found in f ...

Astasia Astasis is a lack of motor coordination marked by an inability to stand, walk or even sit without assistance due to disruption of muscle coordination. The term ''astasia'' is interchangeable with ''astasis'' and is most commonly referred to as '' ...

'') :* Order Eutreptiales :* Order Euglenamorphales :* Order Rhabdomonadales :* Order Sphenomonadales :* Order Heteronematales

Division Chlorarachniophyta

* Class Chlorarachniophyceae (e.g., '' Chlorarachnion'')

Division Chlorophyta

* 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 Chapma ...

:* Order Mamiellales (e.g., '' Mamiella,

Bathycoccus ''Bathycoccus'' is a genus of green algae in the 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 scal ...

'') :* Order Pseudoscourfieldiales (e.g., ''

Nephroselmis ''Nephroselmis'' is a genus of green algae. It has been placed in the family Nephroselmidaceae, although a 2009 study suggests that it should be separated into its own class, Nephroselmidophyceae. One species can be an endosymbiont of ''Hatena ...

'') :* Order

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 '' Amphoraemon ...

(e.g., ''

Pyramimonas ''Pyramimonas'' is a genus of green algae in the order Pyramimonadales.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 Institute ...

Halosphaera ''Halosphaera'' is a genus of green algae in the order 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. T ...

, Pachysphaera'' ''

Pterosperma ''Pterosperma'' is a genus of green algae in the order 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. T ...

'' '' Mesostigma'' :* Genus '' Pedinomonas'' (sometimes classified in the class Pedinophyceae, or Loxophyceae) :* Order Chlorodendrales (e.g., ''

Tetraselmis ''Tetraselmis'' is a genus of phytoplankton. ''Tetraselmis'' is a green algal genus within the order Chlorodendrales, and they are characterized by their intensely-colored green chloroplast, their flagellated cell bodies, the presence of a pyreno ...

'') * Class Chlorophyceae :* Order

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 ...

ncluding_the_Tetrasporales.html" ;"title="Tetrasporales.html" ;"title="ncluding the Tetrasporales">ncluding the Tetrasporales">Tetrasporales.html" ;"title="ncluding the Tetrasporales">ncluding the Tetrasporales(e.g., ''Chlamydomonas, Chlorogonium, Hyalogonium, Gloeomonas, Diplostauron, Polytoma, Carteria, Brachiomonas, Lobomonas, Sphaerellopsis, Haematococcus, Phacotus, Pteromonas, Stephanosphaera,

Gonium ''Gonium'' is a genus of colonial algae, a member of the order Chlamydomonadales. Typical colonies have 4 to 16 cells, all the same size, arranged in a flat plate, with no anterior-posterior differentiation. In a colony of 16 cells, four are ...

Pandorina ''Pandorina'' is a genus of green algae composed of 8, 16, or sometimes 32 Cell (biology), cells, held together at their bases to form a sack globular colony surrounded by mucilage. The cells are ovoid or slightly narrowed at one end to appear Ke ...

, Eudorina,

Volvox ''Volvox'' is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 170 ...

, Pseudosphaerocystis'') :* Order

Chlorococcales Chlorococcales is a formerly recognized order of green algae in the class Chlorophyceae. , the type family Chlorococcaceae was placed in the order Chlamydomonadales. Conventionally, many groups of coccoid green algae were lumped in the order Ch ...

(e.g., '' Chlorococcum, Golenkinia,

Chlorella ''Chlorella'' is a genus of about thirteen species of single-celled green algae belonging to the division Chlorophyta. The cells are spherical in shape, about 2 to 10 μm in diameter, and are without flagella. Their chloroplasts contain the ...

, Chodatella, Oocystis, Kirchneriella, Nephrocytium, Actinastrum, Crucigenia, Sphaerocystis, Coccomyxa,

Scenedesmus ''Scenedesmus'' is a genus of green algae, in the class Chlorophyceae. They are colonial and non-motile. Taxonomy Currently, there are 74 taxonomically accepted species of ''Scenedesmus''. Additionally, several subgenera have been identified, ...

, Hydrodictyon,

Pediastrum ''Pediastrum'' is a genus of green algae, in the family Hydrodictyaceae. It is a photoautotrophic, nonmotile coenobial (fixed number of cells) green algae that inhabits freshwater environments. Morphology ''Pediastrum'' is a genus usually lo ...

, Chlorosarcinopsis, Cylindrocapsa, Geminella, Binuclearia, Radiofilum, Sphaeroplea, Characiosiphon, Atractomorpha'') :* Order Chaetophorales (e.g., '' Uronema, Stigeoclonium, Draparnaldia, Schizomeris'') :* Order Oedogoniales (e.g., '' Oedogonium'') * Class

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 ...

:* Order Codiolales (e.g., '' Chlorocystis,

Ulothrix ''Ulothrix'' is a genus of green algae in the family Ulotrichaceae. ''Ulothrix'' is a genus of non-branching filamentous green algae, generally found in fresh and marine water. Its cells are normally as broad as they are long, and they thrive i ...

, Spongomorpha, Urospora, Acrosiphonia,

Monostroma ''Monostroma'' is a genus of marine green algae (seaweed) in the family Monostromataceae. As the name suggests, algae of this genus are monostromatic (single cell layered). ''Monostroma kuroshiense'', an algae of this genus, is commercially culti ...

'') :* Order

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) have e ...

(e.g., ''

Ulva Ulva (; gd, Ulbha) is a small island in the Inner Hebrides of Scotland, off the west coast of Mull. It is separated from Mull by a narrow strait, and connected to the neighbouring island of Gometra by a bridge. Much of the island is formed f ...

, Enteromorpha, Ulvaria,

Acrochaete ''Acrochaete'' is a genus of marine green algae of the family Ulvellaceae Ulvellaceae is a family of green algae in the order Ulvales Ulvales is an order of green alga The green algae (singular: green alga) are a group consisting of the ...

'') * Class Cladophorophyceae :* Order

Cladophorales Cladophorales are an order of green algae, in the class 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 L ...

(e.g., ''

Cladophora ''Cladophora'' is a genus of reticulated filamentous Ulvophyceae (green algae). The genus ''Cladophora'' contains many species that are very hard to tell apart and classify, mainly because of the great variation in their appearances, which is a ...

Chaetomorpha ''Chaetomorpha'' is a genus of green algae in the family Cladophoraceae.Guiry, M. D. (2004)''Chaetomorpha''.''In:'' Guiry, M. D. & Guiry, G. M. (2017). AlgaeBase. Accessed through: World Register of Marine Species on 9 August 2017. Members of thi ...

, Rhizoclonium, Struvea, Valonia, Siphonocladus, Dictyosphaeria'') * 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 lan ...

:* 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 coenocytic, having multi-nucleate cells consisting of cytoplasm contained withi ...

(e.g., ''

Bryopsis ''Bryopsis'' is a genus of marine 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 (Embr ...

, Pseudobryopsis, Derbesia,

Codium ''Codium'' is a genus of seaweed in the Chlorophyta of the order Bryopsidales. Paul Silva was an expert on the genus ''Codium'' taxonomy at the University of California, Berkeley. There are about 50 species worldwide. Description The genus h ...

'') :* Order Halimedales (e.g., '' Udotea, Penicillus, Halimeda,

Caulerpa ''Caulerpa'' is a genus of seaweeds in the family Caulerpaceae (among the green algae). They are unusual because they consist of only one cell with many nuclei, making them among the biggest single cells in the world. A species in the Mediterran ...

'') * Class Dasycladophyceae :* Order

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 ...

(e.g., ''

Acetabularia ''Acetabularia'' is a genus of green algae in the family Polyphysaceae, Typically found in subtropical waters, ''Acetabularia'' is a single-celled organism, but gigantic in size and complex in form, making it an excellent model organism for stu ...

, Batophora, Dasycladus, Neomeris, Cymopolia'') * Class Trentepohliophyceae :* Order

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 (N ...

(e.g., '' Trentepohlia, Cephaleuros'') * Class Pleurastrophyceae :* Order Pleurastrales (e.g., ''

Trebouxia ''Trebouxia'' is a unicellular green alga.Silverside, A. J. (2009). Retrieved from http://www.bioref.lastdragon.org/Chlorophyta/''Trebouxia''.html It is a photosynthetic organism that can exist in almost all habitats found in polar, tropical, a ...

Myrmecia Myrmecia can refer to: * ''Myrmecia'' (alga), genus of algae associated with lichens * ''Myrmecia'' (ant), genus of ants called bulldog ants * Myrmecia (skin), a kind of deep wart on the human hands or feet See also * '' Copromorpha myrmecias'' ...

, Friedmannia, Pleurastrosarcina, Pleurastrum, Microthamnion'') * Position uncertain: :* Order

Prasiolales Prasiolales is 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 Institute ...

(e.g., ''

Prasiola ''Prasiola'' is a genus of fresh water and marine green algae. Each individual plant is small but they usually grow side by side to form a green turf on rock surfaces. The genus has a cosmopolitan distribution. Occurrence Freshwater species ...

'') * Class

Klebsormidiophyceae 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 an ...

:* Order

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 an ...

(e.g., '' Chlorokybus, Raphidonema, Klebsormidium'') :* Order

Coleochaetales 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 ...

(e.g., ''

Chaetosphaeridium ''Chaetosphaeridium'' is a genus of green algae. Several classifications have been proposed. Its traditional classification is in the order Coleochaetales, related to the genus ''Coleochaete''. AlgaeBase places it in the order Chaetosphaeridiale ...

Coleochaete ''Coleochaete'' is a genus of parenchymatous charophyte green algae in the order Coleochaetales. They are haploid, reproduce both sexually and asexually, and have true multicellular organisation, with plasmodesmata communicating between adjacen ...

'') * Class

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 ...

:* Order

Zygnematales The Zygnematales ( el, ζυγός (''zygós'') and νῆμα (''nḗma'') ( nom.), νήματος (''nḗmatos'') (gen.)), also called the Conjugatales, are an order of green algae, comprising several thousand different species in two families. T ...

(e.g., ''

Spirogyra ''Spirogyra'' (common names include water silk, mermaid's tresses, and blanket weed) is a genus of filamentous charophyte green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is character ...

, Mougeotia, Zygnema,

Spirotaenia ''Spirotaenia'' is a genus of basal green algae that may be sister to the Chlorokybophyceae. It was previously considered to be part of the Zygnemataceae. It is sexually conjugating, a mode of reproduction that was previously only known in th ...

, Cylindrocystis, Netrium'') :* 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 singl ...

(e.g., '' Cosmarium, Gonatozygon, Closterium, Pleurotaenium, Tetmemorus, Euastrum, Micrasterias, Cosmocladium, Xanthidium, Staurastrum, Desmidium, Hyalotheca, Spondylosium, Sphaerozosma, Onychonema'') * Class

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 ...

:* 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 (Ch ...

(e.g., '' Chara, Lamprothamnium, Nitellopsis, Nitella, Tolypella'')

Note added in proof

In a note added in proof, an alternative classification is presented for the class Chlorophyceae: * Class Chlamydophyceae :*Order

:*Order Chaetophorales :*Order

(e.g., '' Chlorococcum, Chlorosarcinopsis, Cylindrocapsa'' * Class Chlorophyceae :* Order Chlorellales (e.g., ''

, Kirchneriella,

, Hydrodictyon,

, Sphaeroplea, Atractomorpha'') * Class Oedogoniophyceae :*Order Oedogoniales (e.g., '' Oedogonium'') Many examples of genus given in the book could not be assigned to one of these classes, because the

ultrastructural Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. This traditionally meant the resolution and magnification range of a co ...

characteristics needed for their classification have not yet been studied.

References

External links

* {{Cite book , last=van den Hoek , first=C. , title=Algae: An Introduction to Phycology , last2=Mann , first2=D. G. , last3=Jahns , first3=Hans Martin , publisher=Cambridge University Press , year=1995 , isbn=9780521304191 Systems of algal taxonomy