Description: This is the iconic ‘Iceland Moss’. It has a loosely attached, shrubby thallus between two and six centimetres tall, a pale, dark red to brown colour with its surface ridged and pitted. The lobes are inrolled often with marginal projection tipped with pycnidia (pimply spots). Medulla Pd+ orange-red (this distinguishes it chemically from C. ericetorum). In hilly, lichen-rich heath usually on mountain slopes. Rare, northern and western Ireland. (Iceland Moss is an important reindeer and caribou staple; it may be eaten by humans, but not without lengthy preparation: not recommended)

Key Identification Features:

• Dark reddish or brown, shrubby thallus, the branches inrolled with marginal ‘spikes’
• Medulla Pd+ red, high upland heaths.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Cetraria islandica at iNaturalist World Species Observations database.