Family: Monoblastiaceae Species: Acrocordia gemmata Growth type crustose Photos: On Sycamore. Ballyrisode, Co. Cork, SW Ireland. Thin, cracked, white to light-grey thallus with large black perithecia, 0.5 to 1mm diameter. The ostiole is often off-centre and sometimes papillate. Scattered pycnidia. Asci usually 8-spored, spores 1(-3) septate, 15-27(-30) x 8-12 µm. Micro photos below. Chemical reactions negative. Widespread on mature, rough-barked trees, especially Oak, Ash and Elm. Rare on Hazel. Similar: Anisomeridium biforme. Smaller perithecia, to 0.5mm

Microscope photographs



Acrocordia gemmata January 2012