 The column typical of the genus Stylidium is sensitive and responds to touch. The change in pressure when a pollinating insect lands on a Stylidium flower causes a physiological change in the column turgor pressure by way of an action potential, sending the column quickly flying toward the insect. Upon impact, the insect will be covered in pollen and stunned, but not harmed. Because the column comprises the fused male and female reproductive organs of the flower, the stamen and stigma take turns in dominating the function of the column — the anthers develop first and then are pushed aside by the developing stigma. This delayed development of the stigma prevents self-pollination and ensures that cross pollination will occur between individuals of a population. Different species have evolved the trigger mechanism in different locations, with some attacking the pollinating insect from above and others from below (a "punch in the gut" to the insect).
