Poepp

Description

Victoria amazonica is a species of flowering plant, the largest of the water lily family Nymphaeaceae. It is the national flower of Guyana. Its native regions are Guyana and tropical South America. The Victoria amazonica has very large leaves, up to 3 m (10 ft) in diameter, that float on the water's surface on a submerged stalk, 7–8 m (23–26 ft) in length, rivaling that of the green anaconda, a snake local to its habitat. It is the largest waterlily in the world. V. amazonica is native to the shallow waters of the Amazon River basin, such as oxbow lakes and bayous. In their native habitat, the flowers first begin to open as the sun starts to set and can take up to 48 hours to fully open. These flowers can grow up to 40 cm (16 in) in diameter. Each plant will continue to produce flowers for a full growing season and they have co-evolved with a species of scarab beetle of the genus Cyclocephala, to improve its pollination, developing a commensal relationship with such species. All the buds in a single patch will begin to open at the same time and as they do, they give off a fruity smell. At this point the flower petals are white and the beetles become attracted to both the colour and the smell of the flower. By nightfall the flower closes, the odor stops being emitted, and the beetle becomes trapped inside the carpellary appendages inside the flower. Here, the stamens are protected by the paracarpels and for the next day the flower continues to remain closed. The cavity in which the beetle is trapped is composed of a spongy, starchy tissue that provides nourishment for the beetle. During this time, anthocyanins start to be released by the plant, which in turn changes the petals from white to a reddish pink colour, a sign that the flower will have been pollinated. As the beetle munches away inside the flower, the stamens fall inward and the anthers, which have already fallen, drop pollen on the stamens. During the evening of the second day, the flowers will have opened enough to release the beetle and as it pushes its way through the stamens it becomes covered in pollen. These insects will then go on to find a newly opened water lily and cross-pollinate it with the pollen they are carrying from the previous flower. This process was described in detail by Sir Ghillean Prance and Jorge Arius.