A Honeybee nectars from the sweet spot on a Nasturtium flower - its spur. Located in the back of the bloom, The Nasturtium evolved its spur to encourage visits by specific pollinators. This feature helps to ensure that pollen from other Nasturtiums is sprinkled on the plants sex organs. Over millennia plants have developed visual cues and physical adaptations which, while literally or practically invisible to people, act as semaphores for the eager pollinators which help ensure their survival.