Family: Lecanographaceae Species: Zwackhia sorediifera (Opegrapha sorediifera) Growth type crustose Photos: Co. Limerick, Ireland. Smooth or scurfy brownish thallus with pale orange-yellow or buff punctiform soralia. Usually sterile but when present apothecia are semi-immersed to sessile, disc slit-like. Spores 30-40(-58) x 4-5 µm, 10-14 septate. Micrographs below. Chemical results: Soralia K-, C+ pink-red, KC+ red, P-, UV- On deciduous trees in damp woods (especially Salix and Acers) Similar: Zwackhia viridis (O. viridis) is the fertile counterpart, spores (8-)11-15 septate with distinct gelatinous sheath, C-. Porina multipuncta (O. multipuncta), C- with fleck-like soralia

Micrographs



Zwackhia sorediifera (Opegrapha sorediifera). December 2024