Living 'together?

Being no botanist, does not mean that a person does not observe the goings-on in nature ...

In our backyard, we have one peach tree which has become the host of lichen. Having learnt of symbiosis in school biology, very, very long ago!, I can remember that where one form of life cannot exist without the other ... this mutual beneficial relationship is called mutualism, (symbiosis).

Info from the Internet calls lichens amongst the most bizarre form of organisms! That is because every species of lichen composes two, or even three, distinct species of life! (One husband - two wives??? Oh no!). One species is a form of FUNGUS,( could this form be male, then?) and having no chlorofil, it cannot photosynthesize its own food. (Sounds famliar , married ladies?)
Usually the other species is an ALGAE( Wife?), but sometimes it can be a photsynthesizing bacterium known as CYANOBACTERIUM (a mistress, perhaps?) Occasionally all THREE organisms are found in one LICHEN.

A lichens Fungal part is thus fed by the photosyntesizing Algal part.

One the other hand the Algae benefit from the association because of the Fungus' ability to find, soak up, and retain water and nutrients .... The Fungus also gives the resulting lichen shape, and provides the reproductive structures .... well, well, who would have guessed? So small, yet so complicated already?