Involucre
Involucre (?; 277) , noun
[Latin involucrum a covering, wrapper, from involvere to wrap up, envelop: compare French involucre. See Involve.]
(a)
(Botany) A whorl or set of bracts around a flower, umbel, or head.
(b)
(Botany) A continuous marginal covering of sporangia, in certain ferns, as in the common brake, or the cup-shaped processes of the filmy ferns.
(c)
(Botany) The peridium or volva of certain fungi. Called also involucrum.