Description: Look out for this crustose lichen growing on limestone, both naturally occurring and in churchyards. It has a pale, cream-brown thallus with tiny discs set into pits (to 0.5mm diam.). The distinctive discs are pink to pink-brown. When dry, they shrink within the pit to leave a thin gap around the edge. The spores are near-globose. The thallus does not scratch orange with a fingernail as in Ionaspis epulotica. In Ireland, it occurs from the Burren northwards; it is absent in the south.

Key Identification Features:

• Creamy thallus with pink discs; does not scratch orange with fingernail
• Discs become looser on drying but are translucent when wet; on lightly sheltered, horizontal limestone.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Hymenelia prevostii at iNaturalist World Species Observations database.