Order: Lecanorales Family: Bacidiaceae
Species: Toninia sedifolia
Photos: On earth among rocks. Barley Cove, Cork, SW Ireland.
Very variable. Squamules +/- rounded or irregularly-lobed, olive-green to brownish with dense white or bluish pruina. Large black flat or angular discs, pruinose when young, margins becoming excluded. The epithecium is greyish, K+ violet. The asci are 8-spored, spores are 1-septate, 14-25 x 2.5-5 Ám. Microscope photograph below.
Occurs on calcareous soil and dunes, on short calcareous turf and in crevices in calcareous rocks.
Similar: Toninia aromatica. Epithecium green, spores 3-septate.