Hi forum members,

During an excursion organised by Antwerpse Mycologische Kring on 9 May 2026 in the Abtsheide nature reserve in Beerse, Belgium, I found black, round ascocarps beneath the epidermis of Carex leaves. The average diameter is 73 to 140 µm, with a central ostiole smaller than 30 µm and without a papilla.
Exipulum: black with a texture varying from prismatica/angularis to intricata
Asci: bitunicate, thick-walled especially at the apex (with a short papilla?); clavate (55–116 × 10–13 µm); containing 8 spores; biseriate to irregular arrangement; reaction to Lugol's solution: dextrinoid;
Spore: subcylindrical to fusiform (sometimes slightly curved), with 1 central septum, slightly constricted at the septum and 2 large and several small droplets in each half; 29–35 × 6–7 µm
Could it be Metasphaeria cumana var. macrospora?
Any help would be most welcome!

Kind regards,
François Bartholomeeusen