Term:

Operculum
Definition:

The lid of the fruit of species with circumscissilely dehiscent fruits as found in many species of Lecythidaceae; a valvelike opening into the stony endocarp of the fruit of some species (e.g., Humiriaceae); referring to a seed with an opening covered by a lid (e.g., Zingiberaceae) or the membranous cover of the nectary in Passiflora (Passifloraceae).
Related Terms:

Dehisce (dehiscent)