The pad of the giant water lily (Victoria amazonica) is the largest water lily in the world. Due to its large size, it has special adaptations to support it in the water while keeping it laid flat. The pattern of supporting ribs is said to have inspired the network of metal girders around which the Crystal Palace was built for Britains Great Exhibition in 1851.
In so-called black water lakes, with relatively clear water, the giant lilies do grow not as big as in white water lakes that carry more sediment, and hence nutrients for growth. As the pad ages it is eaten by insects and other aquatic herbivores.
The underside of the giant water lily is covered with sharp, inch-long spines which protect the pad from herbivorous fishes. The spines are apparently toxic, because being pricked by one is said to be extremely painful. Underwater parts (root and stem) and seed of the plant are edible. The pattern of ribs helps support the huge leaf.