Largest Water Lily Was Hiding in Plain Sight

A royal botanical garden is just the place you'd expect to find the world's largest species of water lily. But until recently, officials at London's Royal Botanical Gardens, Kew, were unaware that the species previously unknown to science, though well known to the indigenous peoples of the Amazon, had been hiding in plain sight there for 177 years. The third known species of giant water lily, Victoria boliviana, which grows in Bolivia's Llanos de Moxos region, was added to the gardens' collection in 1845, per the BBC. But it was only within the last two decades that horticulturist Carlos Magdalena came to suspect that it differed from known species Victoria amazonica and Victoria cruziana.

In 2016, Bolivian gardens donated giant water lily seeds to Kew, allowing a research team to carefully study the plants as they grew side by side under the same conditions. "Once we did this we could very clearly see that every single part of the plant was totally different," Magdalena tells the BBC. Researchers then analyzed the genome of V. boliviana using a specimen collected for the National Herbarium of Bolivia in 1988, which had been mistaken for V. cruziana, per the Guardian. The analysis, described in Frontiers in Plant Biology, revealed "the common ancestor of V. cruziana and V. boliviana split from V. amazonica about 5 million years ago, while the common ancestor of V. cruziana and V. boliviana existed about 1 million years ago," New Scientist reports.

"None of the three species have been very well studied ... because they're so huge—so obvious" and "there are still many unknowns," Dr. Alex Monro of RBG Kew tells the BBC. But researchers believe V. boliviana, with spiny stalks and flowers that turn from white to pink, is the most at risk from extinction because of its small geographic range. Luckily, its large size helps it compete: "The biodiversity in the tropics is so high, so when an aquatic area opens up—for example, because the rivers suddenly become larger due to a flood—the water lilies can thrive there because they grow really quickly and capture so much of the sunlight, and outcompete other plants," researcher Natalia Przelomska tells New Scientist. (More discoveries stories.)