Description: This large erect ‘beard lichen’ has a dense medulla, near-concave shaped soralia and a black holdfast-like base. This last shows a fine network of both vertical and horizontal cracks, like the bonding pattern of a brick wall. The medulla turns Pd+ yellow (slow), the colour showing only after an interval of about one minute. In U. subfloridana (which it most closely resembles), the Pd reaction is instant. Across Ireland, records are few and scattered.

Key Identification Features:

• Blackened base cracked into a brick-like grid pattern
• Soralia concave; medulla Pd+ yellow, changing slowly.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Usnea wasmuthii at iNaturalist World Species Observations database.