Victoria amazonica - Giant water lilies of the Amazon rainforest
26 February 2020 (16512 visits)Victoria amazonica is the largest member of the water lily family (Nymphaeaceae). It was known to science previously as Victoria regia, the name it was given by the English botanist John Lindley, who in October 1837 was the first specialist to publish a description of the genus, based on samples received by the Botanical Society of London, of which he was a distinguished member. The name Victoria regia was chosen to honor Britain’s new monarch Queen Victoria, who as an eighteen-year-old girl had succeeded her father William IV to the throne in June 1837.
In fact, the discovery of this most magnificent of all the Amazon’s aquatic plants was announced in 1801, by the Bohemian-born botanist Thaddäus Haenke, who was a member of the Malaspina Expedition which explored much of the Pacific basin, including coastal North and South America, Australia and New Zealand.
This giant water lily has extremely large, round leaves with upturned rims, which can measure up to 3 meters (almost 10 feet) in diameter. Supported by a ribbed undersurface and anchored to a submerged stalk, these enormous leaves float on the surface of bodies of water within the Amazon basin. The stalks of Victoria amazonica can grow up to 8 meters (26 feet) in length and imbed themselves in the mud at the bottom of lakes or rivers.
The preferred habitat of Victoria amazonica is provided by the oxbow lakes of South America’s rainforests, shallow bodies of water that begin life as the curves or meanders formed by slow-moving rivers as they wind their way through the lowland forests of the Amazon basin. Oxbow lakes are among the best places in the Amazon for observing a wide variety of rainforest fauna, including caimans, birds, and mammals such as the giant otter.
The leaves of Victoria amazonica first appear as spiny structures, before expanding at a rate of up to half a meter (almost 20 inches) a day. The waxy upper surface of the leaf possesses water repellent properties, while the underside is protected from herbivorous fish species by a series of sharp spines. Air is trapped between the structural ribs on the underside of the leaf, keeping the plant afloat.
In addition to their great size, these giant water lilies are remarkable for the flowers they produce, which last for just 48 hours and only emerge at night. When they first emerge the flowers are white, and on their second night of life they take on a purple-red hue. The flowers alone of this uncommonly large and beautiful plant can measure up to 40 centimeters (almost 16 inches) in diameter.
Victoria amazonica water lilies are pollinated by beetles, which on the first night of the flower’s life are attracted by the sweet pineapple-like scent they produce. The beetles are then trapped in the flower as it closes. During the following day, the plant changes from female to male and begins to produce pollen. When the flower opens on the second night, it no longer emits its sweet scent, and the beetle, now coated in pollen, continues on its way, flying to the white flower of another water lily and repeating the process. Once the flower has completed its reproductive task, it closes and the plant is submerged beneath the water.
