Staurodesmus | |
---|---|
Staurodesmus glaber | |
Scientific classification | |
(unranked): | Viridiplantae |
(unranked): | Charophyta |
Class: | Zygnematophyceae |
Order: | Desmidiales |
Family: | Desmidiaceae |
Genus: | Staurodesmus |
Species | |
Synonyms | |
ArthrodesmusEhrenberg ex Ralfs [1] |
Staurodesmus is a genus of green algae, specifically of the Desmidiaceae. [2]
The genus Staurodesmus was first circumscribed by the desmidiologist Einar Teiling. The defining characteristic of the genus is the single, unbranched spines at each angle of the semicell. Cell walls also lack protuberances or other ornamentations, which separate the genus from the similar Xanthidium . [3]
The genus includes species formerly placed in Arthrodesmus and Staurastrum , the difference in the two genera being the number of planes of symmetry: Arthrodesmus was biradiate (having two planes of symmetry), while Staurastrum included species with three or more planes of symmetry. However, over the years desmidiologists found many specimens with one biradiate semicell and another tri- or quadriradiate semicell. As these cells could not soundly be placed into one genus, Teiling erected Staurodesmus; the name was made to be a portmanteau of Arthrodesmus and Staurastrum. [3] Although Staurastrum is still used as a genus, Arthrodesmus is a later homonym (thus invalid) and is no longer used. [4]
Staurodesmus consists of solitary cells that are divided into two symmetrical halves, called semicells. Semicells are diverse in shape, but are unified by having a single, unbranched spine at the angles of the semicells. The cell wall is smooth and lacks ornamentations other than pores or fine granules. Each semicell contains a single chloroplast. [4]
Species of Staurodesmus are distinguished from each other by the shape of the cells, and the size and orientation of the spines. [4]
Ankyra is a genus of green algae in the family Characiaceae. This genus of algae is closely related to Atractomorpha and Sphaeroplea. They are found in stagnant waters.
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 genus common in saline waters.
Atractomorpha is a genus in the Sphaeropleaceae, a family of green algae. The genus name is derived from Greek and means "spindle-shaped" or "arrow-shaped", and refers to the shape of the cells.
Carteria is a genus of green algae in the family Chlamydomonadaceae. Carteria are similar in morphology to the common genus Chlamydomonas and differ by having four, rather than two, flagella at the vegetative stage.
Kirchneriella is a genus of green algae in the family Selenastraceae. It is found in freshwater habitats, as phytoplankton or metaphyton.
Quadrigula is a genus of green algae in the family Selenastraceae. It is commonly found in freshwater habitats as phytoplankton.
Sphaeroplea is a genus of green algae in the family Sphaeropleaceae. It was first circumscribed by the Swedish botanist Carl Adolph Agardh in 1824.
Treubaria is a genus of green algae, the sole genus in the family Treubariaceae. Treubaria is found in freshwater habitats and has a cosmopolitan distribution.
The Desmidiaceae are one of four families of charophyte green algae in the order Desmidiales (desmids).
Cosmarium is a genus of freshwater organisms belonging to the Charophyta, a division of green algae from which the land plants (Embryophyta) emerged.
Desmidium is a genus of green algae, specifically of the Desmidiaceae.
Euastrum is a genus of green algae of the Desmidiaceae family. It lives in acidic waters.
Groenbladia is a genus of green algae, specifically of the Desmidiaceae.
Pleurotaenium is a genus of green algae, specifically of the desmids (Desmidiaceae).
Spinoclosterium is a genus of green algae, specifically of the Closteriaceae. It is rare, but widely distributed in freshwater regions throughout the world.
Staurastrum is a genus of green algae, specifically of the Desmidiaceae.
Triploceras is a genus of desmid in the family Desmidiaceae.
Xanthidium is a genus of green algae, specifically of the Desmidiaceae.
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.
Prescottiella is a genus of green algae in the family Desmidiaceae, containing the single species Prescottiella sudanensis. Originally classified as Micrasterias sudanensis in 1958, it was moved into its own genus by Carlos E. M. Bicudo in 1976, due to its asymmetric character. It is named after Gerald Webber Prescott, an American phycologist.