Description: A crustose species with a thin grey thallus bearing small, flat to concave, orange discs, this lichen is known from the west of Ireland where it grows on soft, siliceous rocks (including boulders) in damp ravines. When near streams, it can resemble some forms of Ionaspis lacustris but has a stouter disc rim and septate spores. In Ireland: Counties Kerry, Cork, Galway, Mayo and Donegal.

Key Identification Features:

• Thallus grey with orange discs; spores are septate; in crevices and ravines
• On soft, weathered rocks and boulders, especially basalt.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Gyalidea hyalinescens at iNaturalist World Species Observations database.