Description: Look out for this species in north and north-west Ireland on the crumbling wall tops of old ruined buildings where it thrives among the moss cushions. The thallus is a spongy bundle of green algal cells that blends easily with the moss cover. Discs lack a prominent rim and range in colour from grey to dull red-brown. Searchers may see similarities between this and Bilimbia sabuletorum which also invades this habitat but the discs are less well defined in V. aestivalis with spores one- to (three-)septate, (three- to nine-septate in B. sabuletorum).

Key Identification Features:

• Thallus a granular bundle or crust of green algal cells (goniocysts); discs grey to red-brown without a well-defined rim (exciple)
• Spores one- to three-septate; among mosses on broken or dilapidated walls of old buildings where it is associated with exposed mortar, also in limestone grassland.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Vezdaea aestivalis at iNaturalist World Species Observations database.