The pollen-receptive surface of a carpel or group of fused carpels, usually sticky. The apical end of the style where deposited pollen enters the pistil.An external tracheal aperture in a terrestrial arthropod.A skin lesion that is a diagnostic sign of some disease.The area of a plant where pollen is deposited for fertilisation. Usually the stigma will bear a sweet solution which can attract bees. In turn, the bees will land on the plant, pick up the pollen grains and transport them elsewhere, i.e. to another plant,.