Chlorophyta 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 use by a particular author. In older classification systems, it is a highly paraphyletic group of all the green algae within the green plants (Viridiplantae) and thus includes about 7,000 species of mostly aquatic photosynthetic eukaryotic organisms. In newer classifications, it is the sister clade of the streptophytes/charophytes. The clade Streptophyta consists of the Charophyta in which the Embryophyta 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, green algae contain chlorophyll a and chlorophyll b and store food as starch in their plastids.
Genus is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.
Streptophyta, informally the streptophytes, is a clade of plants. The composition of the clade varies considerably between authors, but the definition employed here includes land plants and all green algae except the Chlorophyta and the more basal Prasinodermophyta.
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 deep within Charophyta, possibly from terrestrial unicellular charophytes, with the class Zygnematophyceae as a sister group.
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 stepped on.
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 placed in separate orders, e.g. Sycidiales and Trochiliscales.
The Tetrasporales are a formerly recognized order of green algae, specifically the Chlorophyceae, now included in Chlamydomonadales. AlgaeBase places Tetraspora and Tetrasporaceae in Chlamydomonadales.
Udoteaceae is a family of green algae, in the order Bryopsidales.
Hormotila is a genus of green algae in the family Chaetophoraceae.
Chara is a genus of charophyte green algae in the family Characeae. They are multicellular and superficially resemble land plants because of stem-like and leaf-like structures. They are found in freshwater, particularly in limestone areas throughout the northern temperate zone, where they grow submerged, attached to the muddy bottom. They prefer less oxygenated and hard water and are not found in waters where mosquito larvae are present. They are covered with calcium carbonate (CaCO3) deposits and are commonly known as stoneworts. Cyanobacteria have been found growing as epiphytes on the surfaces of Chara, where they may be involved in fixing nitrogen, which is important to plant nutrition.
The Interim Register of Marine and Nonmarine Genera (IRMNG) is a taxonomic database which attempts to cover published genus names for all domains of life, from 1758 in zoology up to the present, arranged in a single, internally consistent taxonomic hierarchy, for the benefit of Biodiversity Informatics initiatives plus general users of biodiversity (taxonomic) information. In addition to containing just over 500,000 published genus name instances as at May 2023, the database holds over 1.7 million species names, although this component of the data is not maintained in as current or complete state as the genus-level holdings. IRMNG can be queried online for access to the latest version of the dataset and is also made available as periodic snapshots or data dumps for import/upload into other systems as desired. The database was commenced in 2006 at the then CSIRO Division of Marine and Atmospheric Research in Australia and, since 2016, has been hosted at the Flanders Marine Institute (VLIZ) in Belgium.
Nitellopsis is a genus of charophyte green algae. Some sources, including AlgaeBase, place it in the family Feistiellaceae. Others place it in the family Characeae.
Crouania is a genus of red algae (Rhodophyta) in the Callithamniaceae family. The name of the genus honours the French born Crouan brothers, Pierre-Louis Crouan and Hippolyte-Marie Crouan. It was first described by Jacob Georg Agardh in 1842, and the type species is Crouania attenuata.
Callithamniaceae is a family of red algae (Rhodophyta) in the order Ceramiales. The family was first described by Friedrich Traugott Kützing in 1843.
Actinoptychus is a genus of diatoms belonging to the family Heliopeltaceae.
Sycidiales is an order of fossil charophyte green algae. The reproductive structures in Sycidales have a calcified cover, called a utricle, that is thought to prevent the zygote being desiccated. Other Paleozoic families lack this cover, as do modern charophytes. Fossils of the family Sycidiaceae are found over the longest time span, from the Silurian to the Carboniferous.
Trochiliscaceae is a family of fossil charophyte green algae. It is the only member of the order Trochiliscales. The reproductive structures in Trochiliscaceae have a calcified cover, called a utricle, that is thought to prevent the zygote being desiccated. Other Paleozoic families lack this cover, as do modern charophytes. Fossils of Trochiliscaceae are from the Devonian.
The Characeae or stoneworts are a family of green algae. This is a partial list of species found in Britain and Ireland.
Feistiellaceae is a family of freshwater green algae in the order Charales.
Chara globularis is a species of charophyte green algae in the family Characeae.
