Growing on calcareous rock. Collema latzelii is similar to some forms of C. fuscovirens, the main differences being: 1) Thinner thallus; 2) The existence of a pseudocortex in the thalline exciple (see the photos with the sections); 3) Apothecia smaller; 4) Ascospores similar in dimensions, but with subglobose spores mixed with ovoid ones, sometimes in the same ascus (see the photo with the asci, where subglobose spores appear in the asci on the right). In observation 179430 I made the microscopy of this species for the first time.