Victoria amazonica

A magnificent giant and its historic place at the University of Oxford Botanic Garden

A giant among waterlilies, Victoria amazonica is a truly magnificent plant with a fascinating life cycle. Native to tropical South America, V. amazonica is probably most famous for its large circular leaves, which span over 2.5 m across and can hold the weight of a small child. Anchored to the muddy floor of the river bed, the leaves rise from the depths as spiny buds which then expand rapidly; in a single season a plant can produce up to 50 leaves, which float on the surface by virtue of little pockets of air between the ribs.

Fascinating flower

The leaves of this plant may be impressive, but their nocturnal flowers are equally so. They do not last long though, perishing after just 48 hours or so, and each plant produces just one flower at a time.

Victoria amazonica in the Lily Pond at the Oxford Botanic Garden, unusually this flower opened during the day.

If you are ever fortunate enough to observe V. amazonica flowering over a 48 hour period you may notice a dramatic change that occurs: on the first evening the flower opens it is white and produces a sweet pineapple-like scent. What you can’t see is the heat released by the flower from a thermochemical reaction. All of these factors combined help to attract the plants pollinators, scarab beetles.

What may also surprise you is that this flower is protogynous, meaning that it switches gender, from female to male, over the 48 hour period. On the first night, the flower is female. Enticed inside the flower the beetles transfer the pollen from other plants to the stigma, and fertilisation takes place. But to ensure fertilisation and to guarantee that the beetles become coated with pollen before moving on the next plant V. amazonica has yet another trick up its sleeve. Before the night is up the flower closes, trapping the beetles inside until the following day. During this time, the flower changes from female to male. The anthers mature and pollen is produced. When it opens again the following evening it is no longer white, it is now a beautiful purplish-red colour. It has also lost its scent and no longer produces heat. The beetles, which have been trapped inside, are now covered in the pollen. Free to leave, the beetles fly off in search of a new white flower and the process is repeated. With the job done, the flower closes up and sinks back below the surface.

V. amazonica and the Oxford Botanic Garden

V. amazonica played an important role in the history of the Oxford Botanic Garden. In fact it is the very reason the Lily House was built. In 1851, Charles Daubeny, the Professor of Botany at the University of Oxford at the time, had the Lily House constructed at the Oxford Botanic Garden. He was inspired after a visit to Chatsworth House, in Derbyshire, where head gardener Joseph Paxton has successfully grown V. amazonica for the first time in Britain. In the new specially designed glasshouse pond, V. amazonica was successfully grown and visitors were charged a shilling to see it.

Victoria amazonica is more difficult to cultivate than its close relative V. cruziana,which is grown at the Oxford Botanic Garden more regularly. The pollinating beetles are not native to the UK so our skilled horticulturalists must undertake the pollination themselves. In the summer of 2018 V. amazonica successfully flowered in the Lily House once more, alongside V. cruziana.

Did you know…?
Victoria amazonica is thought to be the original inspiration for Joseph Paxton’s design of the Crystal Palace in 1851 for the Great Exhibition in London.

Further reading

The BRAHMS Project, D. (2018). Oxford University Plants 400: Victoria cruziana — BRAHMS Online. [online] Herbaria.plants.ox.ac.uk. Available at: https://herbaria.plants.ox.ac.uk/bol/plants400/profiles/UV/Victoriacruziana [Accessed 15 Jan. 2019].

obga.ox.ac.uk. (2018). The Water Lily House | Oxford Botanic Garden and Arboretum. [online] Available at: https://www.obga.ox.ac.uk/lily-house [Accessed 15 Jan. 2019].

Plants of the World Online. (2019). Victoria amazonica (Poepp.) Klotzsch | Plants of the World Online | Kew Science. [online] Available at: http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:605776-1 [Accessed 15 Jan. 2019].

SEYMOUR, R. and MATTHEWS, P. (2006). The Role of Thermogenesis in the Pollination Biology of the Amazon Waterlily Victoria amazonica. Annals of Botany, 98(6), pp.1129–1135.

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