Description: Known only from County Cork and extraordinarily rare being a 1 native of the juniper forests of the Azores, this lichen forms small patches of grey-brown or yellowish crust on rock, the K+ orange, Pd+ orange thallus forming a series of ridges and depressions like a beaded pattern hammered into an antique snuffbox by a silversmith. The spherical discs (0.2–0.3mm diam.) are partially sunken with only the black tips (ostiole) visible. The brown, muriform spores are usually eight/ascus with 11 or less transverse septa.

Key Identification Features:

• Thallus a brown to yellowish, low, sharply beaded crust with the discs almost sunken into the blistered areoles, K+ orange, Pd+ orange
• Spores muriform, in eights, usually 7–9 transverse septa.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Leucodecton isidioides at iNaturalist World Species Observations database.