Description: This species is very rare in Ireland, growing only at one site in County Kerry on willow. The crustose thallus is always immersed in the bark so all that is visible are the tiny, Gyalecta-like concave discs. It occurs mostly on damp, spongy tree bark (usually oak) by ditches in old woodlands under a dappled canopy. The spores are beautiful, spindle-shaped, 8- to14-septate.

Key Identification Features:

• Thallus inapparent; discs like Gyalecta on the smooth areas of spongy bark of old woodland trees by ditches and streams
• Spores spindle-shaped, 8- to 14-septate; never muriform.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Karstenia chrysophaea at iNaturalist World Species Observations database.