Roccellaceae Inoderma subabietinum (Lecanactis subabietina) Growth type crustose Pycnidial pruina K+/- light yellow, C-, UV+ ice-blue, K/UV+ mauve Found on the dry, shaded side of trunks and bases of old Oaks and other acid-barked trees. Also found on thick Ivy stems. Most frequent in coastal areas of SW England. BLS conservation evaluation: LC Sc IR. NIEC 'Old woodland' indicator Thin whitish-grey thallus with abundant globose, white-pruinose, black pycnidia, often with extruded yellowish conidial mass. Apothecia unknown. Conidia 3.7-5 x 1.2-1.7 µm. Microscope photograph below. Similar: Opegrapha vermicellifera. Chemical and UV reactions negative Lecanactis abietina. Thallus UV+ yellow or glaucous grey. Pruina C+ red

Microscope photograph

Inoderma subabietinum (Lecanactis subabietina)
Holton Lee and Studland, Dorset. October 2012 and December 2013