Verrucariaceae Thelidium incavatum Growth type crustose Chemical results negative Common on limestone and other calcareous rocks in graveyards and on natural outcrops Thallus white, greyish or discoloured brown, perithecia immersed in pits but sometimes with the apex projecting. Asci are 8-spored, the spores hyaline, (28)36-46(54) × (11)13-16(20) µm, 3(-5) septate, occasionally with one or two longitudinal septa. Microscope photograph below. Similar: Can be very hard to distinguish from Polyblastia dermatodes. Thelidium decipiens has 1-septate spores.

Microscope photographs





Thelidium incavatum
Wimborne and Puddletown, Dorset. February and May 2017