Order: Pyrenulales       Family: Pyrenulaceae Species: Pyrenula occidentalis Growth type crustose. BLS Burren meeting 2009 Photos: On hazel. Cathair Chomáin, the Burren, W Ireland. Yellow-brown to creamy orange thallus with brownish flecks. Pseudocyphellae absent. Perithecia to 0.6mm. Occurs in western Ireland on smooth-barked trees (specially Hazel, Holly and Rowan) in shaded humid and sheltered sites. It is a characteristic species of temperate rainforests. K+ yellowish and purplish in parts, P+ orange, UV+/- yellow Similar: Pyrenula laevigata, whitish or pale-cream thallus. Pyrenula acutispora has a pale yellowish-grey thallus and usually lateral ostioles

Pyrenula occidentalis. BLS Burren meeting, April 2009