Mycoporaceae Cyrtidula quercus Growth type crustose Chemical results negative Common, usually occurs on young, smooth Quercus (Oak) twigs, occasional on Corylus and rare on Ilex, Malus and Sorbus Thallus immersed, sometimes discolouring the bark. Ascomata irregular in outline, with 1-6 locules under a single blackened involucrellum with central ostiole. Asci 8-spored, spores septate with (3-)4(-5) tranverse septa, becoming submuriform, 12-18(-25) × 4.5-9 µm. Micrographs below Similar: Cyrtidula hippocastani is rare or overlooked on Aspen and other broad-leaved trees, Cyrtidula major is rare on Birch

Microscope photographs





Cyrtidula quercus
On Oak twig. Lilliput and Corfe Mullen, Dorset. February 2020, April 2025