Lichens have yeast, simple and complex fungi and cyanobacteria in a symbiosis.
There are typically more than 3 organisms involved.
The cyanobacteria is often Trebouxia or Trentepohlia but the fungal component and yeast component can vary considerably.
This type of symbiotic organism is called a Holobiont and it just so happens that most organisms are holobionts. In fact many cacti contain symbiotic bacteria, fungi and even yeast, including in their tissues. In some ways they are very lichen-like, but instead of a cyanobacteria as the light eating organism in the relationship, there is a cactus. This endophytic community is also vertically transmitted through the seeds.
Most of what we think of as single organisms are actually communities of organisms living together, lichens were just some of the first holobionts identified, and probably some of the coolest.
