The leaves of a South American goliath dominate the waters of the Oasis Garden’s central pool this season. Santa Cruz water lily (Victoria cruziana) is one of three species of giant water lily—often referred to as water-platters. With leaves up to 6.5 feet in diameter, V. cruziana is the baby of the genus Victoria; V. amazonica and the even larger V. boliviana can grow leaves up to 10 feet in diameter!
You may remember a similar specimen, Victoria ‘Longwood Hybrid,’ from the Arboretum’s summer displays a few years back. Victoria ‘Longwood Hybrid’ is hybrid cross between V. amazonica and V. cruziana and was developed at Longwood Gardens by staff member Patrick Nutt in 1960. This now beloved hybrid of the botanic garden world is known for its improved leaf size (reaching up to 8 feet in diameter), flower, and cold tolerance when compared to both of its parents.
How do these immense lily pads stay afloat? The secret lies beneath the leaf, in a network of sturdy ribs separated by thin and slightly convex tissue. Air bubbles are trapped in the network, making the leaves astonishingly buoyant. Please trust us on this one, and do not try to test the buoyancy by putting objects on the lily pads. We don’t want to have to retrieve your phone, wallet, or wedding ring from the bottom of the Oasis pool!
Victoria water lilies have an upright rim around the edge of each leaf. The stiff edges are thought to prevent neighboring leaves from overlapping and blocking the sunlight needed for photosynthesis. The rims are equipped with a notch that allows water to drain off the surface of the leaf.
The first European collectors to encounter giant water lilies were awed by their beauty. Naturalist Alcide d’Orbigny wrote of a fellow observer, “having visited…a place near the little river called Riochuélo, he had seen from a distance this superb plant, and had well-nigh precipitated himself off the raft into the river, in his desire to secure specimens.”
The eye-grabbing giant water lilies were imported to Europe in the early 1800s and housed in coal-heated greenhouses. By the 1850s, scientific observers had noticed that their flowers were not only beautiful and fragrant, but also…hot! Victoria flowers are thermogenic, meaning they can transform stored chemical energy into heat.
The Santa Cruz water lily blooms for just two days. On the first day, heat produced by the flower increases the diffusion of floral fragrance, luring in pollinators (primarily beetles). In the evening, the flower closes, trapping pollinators within and keeping them warm overnight so that they remain active, ensuring that they leave the next day covered in the maximum amount of pollen. A typical plant can produce as many as 50 flowers each summer season, first opening white and eventually turning pinkish in color.
Be sure to catch a glimpse of this queen of the water lilies during her reign in the Oasis Pool this summer! The Arboretum’s aquatic displays typically peak in July and August but are on view through October.