Stylidiums or as they are more commonly known trigger plants, have an interesting adaptation to ensure that the pollen from different flowers of the same genus is transferred from the anthers to the stigma.
If you look at the close up picture of the flower, you will notice the tiny trigger in the set position. The tip of this column has the anthers which release pollen when ripe. The same column later develops into a stigma.
When an insect lands on the flower the trigger is released and some pollen is deposited on the insect’s back. As the insect visits other flowers the column may have developed into the stigma and strikes the insect in the same area and takes up pollen from other flowers.