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 Sphaeropleales includes vegetatively non-motile unicellular, colonial, or filamentous taxa. They have biflagellate zoospores with flagella that are directly opposed in direction : Sphaeroplea, Atractomorpha, Neochloris, Hydrodictyon, and Pediastrum. All of these taxa have basal body core connections. Motile cells generally lack cell walls or have only a very fine layer surrounding the cell membrane. Other common characteristics include a robust vegetative cell wall, cup-shaped chloroplasts with large pyrenoids, and relatively large nuclei.
Micrasterias is a unicellular green alga of the order Desmidiales. Its species vary in size reaching up to hundreds of microns.
Lemanea is a genus of freshwater red algae, in the order Batrachospermales. Both species are considered to be widespread in the northern hemisphere. Although placed in the Rhodophyta it in fact is green in colour.
Tetradesmus lagerheimii is a green alga in the family Scenedesmaceae. It is also known by its synonym, Scenedesmus acuminatus.
Scenedesmus is a genus of green algae, in the class Chlorophyceae. They are colonial and non-motile. They are one of the most common components of phytoplankton in freshwater habitats worldwide.
Botryococcus is a genus of green algae. The cells form an irregularly shaped aggregate. Thin filaments connect the cells. The cell body is ovoid, 6 to 10 μm long, and 3 to 6 μm wide. Fossils of the genus are known since Precambrian times, and form the single largest biological contributor to crude oil, and are a major component of oil shales.
Chlorococcum is a genus of green algae, in the family Chlorococcaceae. The alga may be useful in the flocculation of lipids from wastewater. It can be found in fresh water, but is more commonly found in soil or subaerial habitats.
Podohedriella is a genus of green algae in the family Selenastraceae. It is found in freshwater habitats or on damp wood.
Polyedriopsis is a genus of green algae in the order Sphaeropleales. As of February 2022, it contained a single species, Polyedriopsis spinulosa. It is found worldwide in freshwater habitats as phytoplankton, but is rare.
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.
Quadrigula is a genus of green algae in the family Selenastraceae. It is commonly found in freshwater habitats as phytoplankton.
Sorastrum is a genus of green algae in the family Hydrodictyaceae. It is a component of the phytoplankton of freshwater ponds, lakes, and ditches. Sorastrum is common in tropical to temperate regions of the world, but due to its small size it is often overlooked.
Korshikoviella is a genus of green algae in the family Characiaceae.
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 are attached by down-growing rhizoids, usually in dense purple-black to rust-colored clumps. The chloroplasts of Bangia, like others in the division Rhodophyta, contain chlorophyll a and sometimes chlorophyll d, as well as accessory pigments such as phycobilin pigments and xanthophylls. Depending on the relative proportions of these pigments and the light conditions, the overall color of the plant can range from green to red to purple to grey; however, the red pigment, phycoerythrin, is usually dominant.
Tetradesmus obliquus is a green algae species of the family Scenedesmaceae. It is commonly known by its synonym, Scenedesmus obliquus. It is a common species found in a variety of freshwater habitats.
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 2017, some 237 different diterpenes had been identified from across the genus.
Cosmarium botrytis is a species of green algae in the family Desmidiaceae. It is a freshwater species with a worldwide distribution, and has been recorded from all continents.
Aphanothece is a polyphyletic genus with 63 accepted species. The name is derived from the Greek words, ‘aphanes’ and ‘theke’ which mean “invisible" and “box or sheath” respectively. This genera is cosmopolitan, found in soils, thermal springs and other benthic, freshwater, marine, hypersaline, and moist terrestrial environments. Morphology can vary, with both microscopic and macroscopic colonies large enough to be collected and preserved in herbarium records.
