Involucel

from The Collaborative International Dictionary of English v.0.48

Involucel \In*vol"u*cel\ (?; 277), n. [Dim. of involucre, or
   involucrum: cf. F. involucelle.] (Bot.)
   A partial, secondary, or small involucre. See Illust. of
   {Involucre}.
   [1913 Webster]