What is the function of sori?

A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. This New Latin word is from Ancient Greek σωρός (sōrós 'stack, pile, heap'). In fungi and lichens, the sorus is surrounded by an external layer.

A sorus is a cluster of sporangia in ferns and fungi. In fungi and lichens, the sorus is surrounded by an external layer. The sori is a cluster of sporangia which contains the spores in plants like ferns & moss. The spores are essential for reproduction.