apothecial disk (noun, pl. disks;ascocarp term; variant spelling: ... disc) – the exposed upper surface of the hymenium in an open, apothecioid ascocarp. It may be plane, concave or convex and is usually enclosed or at least surrounded by a margin or rim. Related terms: columnella, gyrodisk, gyrus, leiodisk, omphalodisk, umbo. This is:part of ascocarp.