Order: Lecanorales       Family: Megalariaceae Species: Megalaria grossa Growth type crustose. Photos: The Burren, Co. Clare, Glengarriff woods, Co. Cork, Ireland Thallus pale green-grey or whitish, +/- smooth, often with black prothallus. Large matt-black apothecia, the thick shiny margins excluded as disc becomes convex. The asci are 8-spored, the spores 1-septate, 20-30 x 10-15 µm. Isidia and soredia are absent. Microscope photographs below. Thallus: Chemical reactions negative. Hypothecium dark blue-green, K+ green. Found in old, humid woodlands in West and SW Ireland on nutrient-rich bark of Ash, Field Maple and Hazel. Similar: M. pulverea Thallus K+ yellow, P+ red, yellow or negative

Microscope photographs



Megalaria grossa. April 2009 and May 2012