Xanthocarpia crenulatella (Nyl.) Frödén, Arup & Søchting

back to index

On exposed aggregate concrete top of a trashbin housing. Partially in shade. Parasitic on Verrucaria sp. (cf. nigrescens).

This is part of my recent (June 2025) dive into "small yellow/orange nightmares",  mostly microlichens with yellow and orange apothecia. Please take my ID suggestion with caution.

One of the decisive problems was my interpretation of the septum with. The ID as X. crenulatella is on the basis that the septum is "narrow" - my measurements are right on the borderline given in the ITALIC 8.0 key (+/- 3µm).  Example images in the ITALIC species description show spores similar to those observed in this sample.  When treated as wide I get to A. holocarpa and others which have definitively wider septa. 

The ecology and description as "perhaps parasitic of Verrucaria nigrescens when young" matches my observation very well

back to index