Order: Pyrenulales       Family: Pyrenulaceae Species: Pyrenula macrospora Growth type crustose. Photos: On hazel, the Burren, and on Oak and Sycamore, Co. Cork, Ireland. Specimens on Oak and Sycamore identified by J Douglass Waxy olive-brown to creamy yellow thallus with flecks of white pseudocyphellae. Mosiac-forming, black prothallus. Globose black perithecia to 1mm, becoming prominent with a visible ostiole when mature. Common throughout Ireland on shaded, smooth-barked trees. K+ yellow, UV+ yellow or orange or UV- Similar: Pyrenula chlorospila Smaller perithecia.

Pyrenula macrospora. April and November 2009