Description: This crustose, aquatic lichen is characteristic of the submerged zone of streams, rivers and loughs and should be searched for at low water. The grey-green to brown slightly cracked thallus is like a skin. The spherical discs are immersed in warts (0.5 diam) which arise singly and in little clusters. The spores are dark brown, muriform and develop in two-spored asci (sacks containing the spores). Algal cells are present in the discs. Throughout Ireland.

Key Identification Features:

• Grey-green to brown, skin-like thallus dotted with prominent perithecia
• Perithecia immersed in warts; spores two per ascus; algal cells also occur within the disc.

Original text submitted by Vince J. Giavarini

Distribution Map from NBN: Staurothele fissa at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Staurothele fissa at iNaturalist World Species Observations database.