convolute

adjective

(L. convolutus: rolled around, wrapped) Said of parts rolled or twisted together when in an undeveloped stage, as in some corollas in the bud stage, a form of imbricate aestivation in which each segment has one edge overlapping the adjacent segment, like a furled umbrella; rolled together and forming a sheath; e.g. perichaetial leaves of Holomitrium.