Verrucariaceae Parabagliettoa dufourii (Verrucaria dufourii) Growth type crustose Chemical results negative Found on hard, horizontal natural limestone and also occurs on limestone tombstones in older churchyards An immersed pale grey to brownish-grey thallus without a visible prothallus, often only visible as specks of pale grey or fawn-grey. Black perithecia form distinct projections, the apex flat or concave with an inconspicuous ostiole and shallow pits are left when they decay. Brown pycnidia are frequent. Similar: Verrucaria pinguicula is possibly a more northern species

Verrucaria dufourii
On limestone. Portland, Dorset. March 2016