In mosses , cyanobacteria are major nitrogen fixers .
In mosses , cyanobacteria grow mostly epiphytically , aside from two species of Sphagnum which protect the cyanobiont from an acidic - bog environment .
In mosses , cyanobacteria are major nitrogen fixers and grow mostly epiphytically , aside from two species of Sphagnum which protect the cyanobiont from an acidic - bog environment .