Research indicates that consumption of "Nostoc commune" var. The photobiont is the cyanobacterium genus "Nostoc". Cyanobacteria are mostly taxa which display nitrogen fixing such as "Calothrix", "Nodularia" and "Nostoc". Strain PCC 7120 and "Nostoc punctiforme". Common cyanobacterium partners include are "Nostoc" or "Scytonema". It is the type species of the genus "Nostoc" and is cosmopolitan in distribution. Instead, it forms an endocytobiotic association with "Nostoc" cyanobacteria. These cyanobacterial isolates closely relate to the taxonomic group of "Nostoc". These perform photosynthesis, and the "Nostoc" also fixes nitrogen. "Anabaena variabilis" is a phylogenic-cousin of the more well-known species "Nostoc spirrilum". The most commonly occurring genera of symbiotic cyanobacteria are "Nostoc" and "Scytonema". Writing in the "Sanitarian", Leopold Brandeis identified the substance as "Nostoc", a type of cyanobacteria. "Nostoc commune" is a colonial species of cyanobacterium. Nostoc commune is a species of cyanobacterium in the family Nostocaceae. The main representatives of these cyanobacterial felts are "Calothrix", "Nostoc" and "Phormidium".