Family: Arthoniaceae Species: Coniocarpon cuspidans (Arthonia elegans) Growth type crustose Photos: Dromore, Co. Cork, SW Ireland. Immersed whitish-yellow or yellowish-brown thallus usually with delimiting orange-brown line. Linear, branched or stellate apothecia, purplish-brown, without pruinose edges. Spores (2-)3(-4) septate with upper cell enlarged, (15-)16-18(-20) x (6-)7-8(-9) µm. Pycnidia absent. Micrograph below. Apothecia K+ red-purple Found in sheltered woodland, often on the smooth bark of Hazel (Corylus) and young Oak (Quercus). Similar: Coniocarpon cinnabarina (Arthonia cinnabarina) and Arthonia radiata. C. fallax has orange-red pruinose margins

Micrograph

Coniocarpon cuspidans (Arthonia elegans). August 2024