Description: This crustose twig epiphyte is common on acid-barked trees and wood. It has the appearance of L. chlarotera and allied taxa with numerous brown discs with white disc margins. Some of these are best separated using spot tests. First test the disc (thalline) margin with Pd. In L. pulicaris it turns Pd+ rust-red. This twins it with L. intumescens which has a thick margin and discs up to 2mm diam. In L. pulicaris the disc rarely exceeds 1mm diam. with a narrow disc margin. Scattered in northern half of Ireland only.

Key Identification Features:

• Twig epiphyte of acid-barked trees (not to be found on ash, maple, elm or sycamore); a L. chlarotera lookalike
• Disc rarely exceeding 1mm diam.; margin narrow, Pd+ rust-red.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Lecanora pulicaris at iNaturalist World Species Observations database.