Description: In urban areas especially, this species is spreading to dominate old areas of concrete and mortar especially where flat and close to the ground, for example, below sea defences. The biggest spread in recent years has been across untreated, garden patios. From a standing position the species resembles the ubiquitous lichen Protoblastenia rupestris (described elsewhere) but close study shows this species to have flatter, more orange-yellow discs with a clear yellow margin and very different spores. North and south-west Ireland.

Key Identification Features:

• On horizontal concrete and patio slabs; discs flat to slightly convex (very convex, lumpy or clustered in Protoblastenia rupestris)
• Discs with a margin; colonies spreading across several centimetres.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Xanthocarpia crenulatella at iNaturalist World Species Observations database.