Perigone
Perigone , noun
[Prefix peri- + Greek {not transcribed} productive organs.]
1.
(a) (Botany) Any organ inclosing the essential organs of a flower; a perianth.
(b)
(Botany) In mosses, the involucral bracts of a male flower.
2.
(Zoology) A sac which surrounds the generative bodies in the gonophore of a hydroid.