王莲种

它原产于亚马逊河盆地，被圭亚那当作国花。

亚马逊王莲的叶子直径可达三米，茎长可达七至八米。刚开的花呈白色，但一夜之间就会变成粉色。花的直径也有40厘米。

刚开花时，白色花瓣散发浓烈香味，将强力吸引金龟子(或其他昆虫)前来授粉，当金龟子飞来时，花朵会轻轻阖上，让包裹在花瓣中的金龟全身沾满睡莲的花粉。大约二十四小时后，同株睡莲的花瓣将转变成红(粉)色，而且轻轻开启，红(粉)色的睡莲不再吸引金龟，而沾满花粉的金龟会飞向下一株白色睡莲花，此为热带雨林中的艰困环境所促成演化而出的一套复杂又精致的繁衍机制，以提高成功繁衍的几率。

Victoria amazonica ("giant water lily") is a species of flowering plant, the second largest in the water lily family Nymphaeaceae. It is called Vitória-Régia or Iaupê-Jaçanã ("the jacana's waterlily") in Brazil and Atun Sisac ("great flower") in Inca (Quechua). Its native region is tropical South America, specifically Guyana and the Amazon Basin.

Taxonomy

The species is a member of the genus Victoria, placed in the family Nymphaeaceae or sometimes in the Euryalaceae. The first published description of the genus was by John Lindley in October 1837, based on specimens of this plant returned from British Guiana by Robert Schomburgk. Lindley named the genus after the newly ascended Queen Victoria, and the species Victoria regia. The spelling in Schomburgk's description in Athenaeum, published the month before, was given as Victoria Regina. Despite this spelling being adopted by the Botanical Society of London for their new emblem, Lindley's was the version used throughout the 19th century.

An earlier account of the species, Euryale amazonica by Eduard Friedrich Poeppig, in 1832, described an affinity with Euryale ferox. A collection and description were also made by the French botanist Aimé Bonpland in 1825.

Description

Victoria amazonica has very large leaves (lamina; commonly called "pads" or "lily pads"), up to 3 m (10 ft) in diameter, that float on the water's surface on a submerged stalk (petiole), 7–8 m (23–26 ft) in length, rivaling the length of the green anaconda, a snake local to its habitat. These leaves are enormously buoyant if the weight is distributed evenly over the entire surface of the leaf (as by a piece of plywood, which should be of neutral buoyancy). In 1896 a V. amazonica leaf at Tower Grove Park, Saint Louis, Missouri bore the "unprecedented" weight of 110 kg (250 lb). However, in 1867 William Sowerby of Regents Park Botanic Garden in London placed 194 kg (428 lb) on a leaf only 168 cm (66 in) in diameter. One leaf of a specimen grown in Ghent, Belgium bore a load of 226 kg (498 lb) It is the second-largest waterlily in the world.

Ecology

Each plant continues to produce flowers for a full growing season, and they have co-evolved a mutualistic relationship with a species of scarab beetle of the genus Cyclocephala as a pollinator. 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 are attracted both to the colour and the smell of the flower. At nightfall the flower stops producing the odor, and it closes, trapping the beetles inside its carpellary appendages. 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.

Cultivation

V. amazonica is cultivated in botanical gardens worldwide, requiring warm water temperatures of 29–32°C (85–90°F) for optimal growth; mature plants tolerate slightly cooler conditions (24–27°C or 75–80°F). Propagation is primarily by seed, which should be stored submerged in water and scarified to accelerate germination. Rhizome division is also possible during the growing season. In temperate regions, it is grown as an annual in containers with organically rich loam substrate in still water 1–3 m deep.

History

Victoria regia, as it was named, was described by Tadeáš Haenke in 1801. It was once the subject of rivalry between Victorian gardeners in England. Always on the lookout for a new species with which to impress their peers, Victorian "gardeners" such as the Duke of Devonshire and the Duke of Northumberland started a friendly competition to become the first to cultivate and bring to flower this large lily. In the end, the two aforementioned dukes became the first to achieve this, Joseph Paxton (for the Duke of Devonshire) being the first in November 1849 by replicating the lily's warm swampy habitat, and a "Mr Ivison" the second and more constantly successful (for Northumberland) at Syon House.

The species captured the public's imagination and was the subject of several dedicated monographs. The botanical illustrations of cultivated specimens in Fitch and W.J.