Record breaking: Giant Amazon water lily

The leaves of the giant Amazon water lily grow over 2.5m (8’) across. The flowers are 30cm (12’’) wide and the leaf stalks grow with rising flood waters to exceed 6m (20’) long. This extraordinary relative of the garden-favourite lily was discovered in 1801 in a slow moving tributary of the Amazon River.

In 2002, the giant Amazon water lily growing at The Living Rainforest set a world record with a leaf 2.65m (8’ 6½’’) across. Our lily is a hybrid between the two South American species; Victoria amazonica and V. cruziana. It was first raised in 1960 by Patrick Nutt at Longwood Gardens in America.

Adapted to river life

Defensive spines: The lily is well defended from fish and other animals by sharp spines on the flower buds, leaf stalks, and underside of leaves. In contrast, the leaf surface feels smooth to touch and slightly rubbery.

Staying afloat: The lily pads have tremendous buoyancy from a web-like structure of veins – all filled with air. The leaf pads can even support the weight of a well balanced adult. The leaves drain excess surface water with notches at the edge of each leaf.

Capturing light: Along with some other tropical plants, the giant lily leaves are red underneath. This lets the lily capture different wavelengths of light, particularly in lower light levels. Our Victoria x ‘Longwood Hybrid’ is especially red underneath compared with the two water lily species.

Night-time pollination

First evening: The pure-white flowers open during the evening with a pineapple-like fragrance. A chemical reaction inside the flower heats the bloom to as much as 12°C (20°F) above the ambient temperature, helping to disperse the perfume and attract the scarab beetle pollinator (Cylocephata castaneal). This flower is initially female and receptive to pollen carried by a beetle from another flower.

Second evening: As daylight approaches the flower shuts, trapping the beetle. During the day, the flower becomes male and produces pollen that coats the beetle as it tries to escape. The flower reopens the following evening as a dark pink. This colour is unattractive the pollen-coated beetle which travels to another white flower.

A blooming history

The first giant water lily to flower in the UK was grown by horticulturalist Sir Joseph Paxton, head of the Duke of Devonshire’s gardens at Chatsworth House.

Paxton had received the plant from the Royal Botanic Gardens, Kew in 1849 and grown it a specially built greenhouse. Inspired by the structure of the leaf, he later incorporated the lily into designs for his Crystal Palace built for the Great Exhibition of 1851 in London.

Annual spectacle

We plant a young water lily every year in May. The leaves grow several inches a day and reach the edge of our pool by August, when the lily also flowers.

By November, the light levels have dropped too low to sustain the lily over winter and the dying plant is removed. But in the native Amazon, the plant would continue growing year-round where its growth rate is determined by water levels rather than light or warmth.