Description: This conspicuous lichen of nutrient-enriched trees differs from C. nigrescens in its isidia-free thallus and broader spores (6-6.5&

371;m compared to 3-4.5&

371;m). C. furfuraceum is also similar, but has isidia. It is known from Counties Kerry, Galway and Clare, and more recently from the north-west. It is rare on blackthorn, hazel and oak. There is some debate as to whether some historical records of this species refer instead to the rarer C. nigrescens.

Key Identification Features:

• Thallus without isidia; discs common; spores broader than in C. nigrescens
• On nutrient-rich bark and rock, mostly in the oceanic woodlands of the west.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Collema subnigrescens at iNaturalist World Species Observations database.