Coloured scanning electron micrograph (SEM) of lily pollen. The distinctive texture on each pollen grain is designed to enhance adherence to insects, such as bees and butterflies, that visit the flowers. These structural adaptations are critical for ensuring that pollen is efficiently transferred between flowers, aiding in cross-pollination. The allergenic properties of lily pollen are notable. Despite their microscopic size, these grains can have a profound impact on human health, triggering allergic reactions in susceptible individuals. Magnification: x470 when printed 10 centimetres wide.