Description: Buellia subdisciformis (K+yellow-red), one of the most frequent lichens of siliceous rocky shores resembles a larger version of this very rare species. When searching for B. excelsa (K+ yellow, Pd-) it is best to spot test candidates with K. A squash of the disc should reveal the presence of numerous oil droplets; spores 11-15&

371;m long. In Ireland, it is known from the Mount Doughruagh area of Connemara, County Galway.

Key Identification Features:

• The white areolate, warted crust of this lichen is a miniature version of B. subdisciformis. It could also be confused with Amandinea lecideina. Neither of these lookalikes is K+ yellow
• Siliceous rocks.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Buellia sequax at iNaturalist World Species Observations database.