reproductive structure - the parts of a plant involved in its reproduction

style - (botany) the narrow elongated part of the pistil between the ovary and the stigma

demerit - a mark against a person for misconduct or failure; usually given in school or armed forces; "ten demerits and he loses his privileges"

bend sinister, bar sinister - a mark of bastardy; lines from top right to bottom left

cloven foot, cloven hoof - the mark of Satan

symbol - an arbitrary sign (written or printed) that has acquired a conventional significance

spiracle - a breathing orifice

blemish, mar, defect - a mark or flaw that spoils the appearance of something (especially on a person's body); "a facial blemish"