Pitcher plants (Sarracenia flava 'Maxima). This insectivorous plant produces a sweet smelling nectar to attract insects. When an insect alights on the rim of one of the plants, it loses its grip on the waxy, downward-facing detachable scales which line the inside of the pitcher. The insect falls into a liquid at the bottom of the pitcher which contains digestive juices. Insects provide the plants with nitrogen, which is lacking from the soils that the plants grow in. The flap above the opening of the pitcher plant is to prevent rain entering the pitcher and diluting the juices.