Sorus
（重定向自Indusium）
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. In some red algae it may take the form of a depression into the thallus.