A crustose species with a dark brown thallus that is regularly cracked into smooth areoles. Perithesia cover the thallus.
Verrucaria nigrescens is common throughout coastal and lowland Scotland where it occurs on well-lit calcareous rocks, walls and mortar, including gravestones. BLS distribution map
Verrucaria nigrescens can be parasitised by Placopyrenium fuscellum.