proper margin (noun, pl. proper margins;ascocarp term; synonym: true margin) – a morphological term referring to a rim formed by hyphae derived from the ascocarp itself; more or less equivalent with the ascocarp wall; in apothecioid ascocarps generally similar in colour, texture and appearance to the disk; typically present in all ascocarps of ascomycetes, whether lichenized or not. In some lichenized ascomycetes the proper margin may be considerably reduced to a thin, but distinct internal ring forming a corona or parathecial crown. This parathecial crown is typically surrounded by a broadened thalline margin. In other lichenized ascomycetes the proper margin becomes even more strongly reduced and morphologically sometimes can no longer be distinguished. Anatomically, some hyphae from the proper exciple are, however, usually present, and therefore can still be detected, if apothecia are sectioned. In lirellate ascocarps the lateral walls that are anatomically identical with the proper exciple, appear lip-shaped and are then frequently called labiae. This is:part of ascocarp.