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 may be discoid, plate-like, reticulate, cup-shaped, spiral- or ribbon-shaped in different species. Most of the members have one or more storage bodies called pyrenoids located in the chloroplast. Pyrenoids contain protein besides starch. Some green algae may store food in the form of oil droplets. They usually have a cell wall made up of an inner layer of cellulose and outer layer of pectose.
Chlamydomonas is a genus of green algae consisting of about 150 species of unicellular flagellates, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "snow algae". Chlamydomonas is used as a model organism for molecular biology, especially studies of flagellar motility and chloroplast dynamics, biogenesis, and genetics. One of the many striking features of Chlamydomonas is that it contains ion channels (channelrhodopsins) that are directly activated by light. Some regulatory systems of Chlamydomonas are more complex than their homologs in Gymnosperms, with evolutionarily related regulatory proteins being larger and containing additional domains.
Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae. Chlamydomonadales can form planar or spherical colonies. These vary from Gonium up to Volvox. Each cell has two flagella, and is similar in appearance to Chlamydomonas, with the flagella throughout the colony moving in coordination.
Pandorina is a genus of green algae composed of 8, 16, or sometimes 32 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 keystone- or pear-shaped. Each cell has two flagella with two contractile vacuoles at their base, an eyespot, and a large cup-shaped chloroplast with at least one pyrenoid.
Polytoma is a genus of green algae in the family Chlamydomonadaceae. Polytoma is a genus of colorless, free-living chlorophytes similar in form to Chlamydomonas but lacking chlorophyll. Two flagella emanate from the anterior papilla of the cell, and cells have two contractile vacuoles at the flagellar base. Polytoma possesses a leukoplast in place of a chloroplast, in which many starch grains are concentrated; there is no pyrenoid. Since they lack photosynthetic capability, Polytoma species are entirely saprotrophic, obtaining nutrients from decaying organic matter. Some species possess an eyespot apparatus (stigma) in the anterior portion of the leucoplast, but in others this organelle is absent.
Astrephomene is a genus of green algae in the family Goniaceae, order Chlamydomonadales. The genus was first described in 1937 by Pocock and named by Pockock in 1953.
Asteromonas is a genus of green algae in the family Asteromonadaceae. It has been described from saline, marine, and brackish environments. It is closely related to the genus Dunaliella, another species common in saline waters.
Brachiomonas is a genus of thalloid biflagellate green algae. These algae generally are found in marine or brackish waters, but can tolerate wide range of salinities. They may occur in freshwater pools near the sea and, occasionally, in polluted inland freshwater habitats.
Characiochloris is a genus of green algae in the family Characiochloridaceae. Characiochloris is epiphytic on freshwater algae, or found in soil.
Characiosiphon is a genus of green algae in the family Characiosiphonaceae. It contains a single species, Characiosiphon rivularis.
Chlainomonas is a genus of algae in the family Chlamydomonadaceae. They are found in freshwater habitats or on snow, where they are one of the main algae responsible for causing watermelon snow.
Lobocharacium is a genus of green algae in the family Characiosiphonaceae. It contains the single species Lobocharacium coloradoense. It has been isolated from a pond in Colorado, United States.
Platydorina is a genus of microscopic green algae in the family Volvocaceae. It contains only one species, Platydorina caudata. It was described by Charles Atwood Kofoid in 1899.
Pseudoschroederia is a genus of green algae in the family Characiaceae. It is planktonic in freshwater habitats, and probably has a cosmopolitan distribution. The genus Pseudoschroederia was circumscribed by Eberhard Hegewald and Eberhard Schnepf in 1986. The genus was distinguished from the similar Schroederia by being heteropolar and differing cell structure. However, some authors do not consider the genera to be separate.
Raphidocelis is a genus of green algae in the family Selenastraceae. They are found in freshwater habitats.
Schroederia is a genus of green algae in the family Schroederiaceae. Schroederiaceae is a monotypic taxon; Schroederia is its only genus.
Stephanosphaera is a genus of green algae in the family Haematococcaceae, containing the single species Stephanosphaera pluvialis. It forms colonies of flagellated cells. Although it was once placed in the family Volvocaceae, it is not closely related to them; its sister is the unicellular genus Balticola.
Korshikoviella is a genus of green algae in the family Characiaceae.
Chlorokybus is a multicellular (sarcinoid) genus of basal green algae or charophyte. It has been classified as the sole member of the family Chlorokybaceae, which is the sole member of the order Chlorokybales, in turn the sole member of the class Chlorokybophyceae. It grows on soil and rock surfaces, and is rare.
Cecidochloris is a green algae genus in the family Chlorangiellaceae. It occurs in freshwater. However, it has only been reported so far from Europe, with an additional species from India that is incompletely described.
