Description: As one of the ‘bark pimple’ tribe with one-septate spores, this lichen can be difficult to separate from lookalikes such as A. punctiformis and A. nitescens (both described elsewhere). The thallus is generally browner than that of A. nitescens. A good field character to look for is the tip of the discs (perithecia) for the pore-like opening or ostiole. In a good number of examples of A. salicis this is markedly sunken or depressed as though squashed down. It grows on smooth-barked trees such as hazel. Widespread; northern half of Ireland mostly.

Key Identification Features:

• Thallus pale to dark brown and discs with a depressed ostiole
• Spores one-septate, the lower of the two cells with an hourglass shape.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Arthopyrenia salicis at iNaturalist World Species Observations database.