Mägede hääl

Sorus

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 lichens and other fungi, the sorus is surrounded by an external layer. In some red algae, it may take the form of depression into the thallus. In ferns, the sori form a yellowish or brownish mass on the edge or underside of a fertile frond. In some species, they are protected during development by a scale or film of tissue called the indusium, which forms an umbrella-like cover. Sori occur on the sporophyte generation, the sporangia within producing haploid meiospores. As the sporangia mature, the indusium shrivels so that spore release is unimpeded. The sporangia then bu… more »