Plants commonly called rhododendrons and azaleas both belong to the genus Rhododendron. These deciduous or evergreen woody plants bear five-lobed flowers in spring or summer months, typically. Pollination by insects results in seed development and release in the fall.
Social insects are primary pollinators of rhododendron and azaleas -- bumblebees, honeybees and other local bees. In regions where bees aren't abundant, such as in alpine ecosystems, ants may be the primary pollinator. Other insects such as beetles, flies or butterflies also visit the flowers in various habitats.
Rhododendron flowers produce sticky, dripping pollen from anthers as blossoms open. The female pistil, which receives pollen, doesn't become sticky and receptive to pollen for a couple days later. This prevents self-pollination.
Rhododendron and azalea plant parts, including flowers, contain toxins that mustn't be consumed. Since bees are primary pollinators, nectar and pollen containing these toxins leads to poisonous honey. A famous episode dates from Greece in 4 B.C. when 10,000 soldiers ate honey made from Pontic azalea (Rhododendron luteum) and became sick.