Hormogonales
Encyclopedia
The term Hormogonales formerly indicated an order inside the class Cyanobacteria comprising the former suborders "Nostocales
", "Scytonematales" and Stigonematales
. Some genera belonging to Hormogonales were Anabaena
, Nostoc
, Rivularia, Scytonema
and Stigonema.
Nostocales
The Nostocales order contains most of the species of cyanobacteria. It includes filamentous forms, both simple or branched, and both those occurring as single strands or multiple strands within a sheath. Some but not all members show a decrease in width from the base...
", "Scytonematales" and Stigonematales
Stigonematales
Stigonematales is the order of cyanobacteria that includes filamentous strains that produce hormogonia and exhibit true branching. Under the more recent classification system devised by Rippka et al., these strains are listed under section V .-References:...
. Some genera belonging to Hormogonales were Anabaena
Anabaena
Anabaena is a genus of filamentous cyanobacteria that exists as plankton. It is known for its nitrogen fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanobacteria that produce neurotoxins, which are harmful to...
, Nostoc
Nostoc
Nostoc is a genus of cyanobacteria found in a variety of environmental niches that forms colonies composed of filaments of moniliform cells in a gelatinous sheath.The name "Nostoc" was invented by Paracelsus...
, Rivularia, Scytonema
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 species grow on terrestrial rocks, wood, soil, or plants...
and Stigonema.