Ascomycetes also produce spores not in an ascus, but on the sides or at the tips of special hyphal filaments. These structures are called conidiomata and the spores they produce are called conidiospores. Conidiomata come in different forms but by far the commonest is the Pycnidium, see below. The other main types of fungal partner are Basidiomycetes. Basidiomycetes are relatively rare as lichen partners, and one of the ways they differ from Ascomycetes is that they produce their spores on a basidium, a special structure which normally holds four spores at its top.
Spores come in a great variety of sizes, shapes and forms.
They are for instance, much larger in the genus Pertusaria than in the genus Acarospora . Many are simply a single whole spore while in others the spore may be divided up into 2 or more subsections. These spores are all microscopic in size and float easily in the air, this enables them to disperse widely when they are released. Quite how these spores meet up with the correct algal partners to form new Lichens is something nobody really understands, though as most of the algae occur in the wild on their own it may be that it is simply a matter of chance that some will come to rest on the right algae. Apothecia normally look like exposed disks which may be raised above the surface of the thallus, level with it or sunk below the surface level.