Verrucaria squamulosaP3229.jpg

Description:
Verrucaria squamulosa, showing overlapping green areoles. This specimen (Powell 3229) is from a crevice in a retaining wall, Southend-on-Sea; it is sterile but contains inconspicuous pycnidia within the thallus. Red pencil lead (0.5 mm diameter) for scale.
Taxonomic name: