perigonium(n = noun.plant) chlamys, floral envelope, perianth, perigone - collective term for the outer parts of a flower consisting of the calyx and corolla and enclosing the stamens and pistils;
is a kind of cover, covering, natural covering, plant organ
is a part of bloom, blossom, flower
has parts: corolla, calyx
has particulars: falls

   Same as Perigone. [1913 Webster]