The world's biggest waterlily species was hiding in plain sight all along

Scientists have discovered a new waterlily species for the first time in 177 years in London's Royal Botanic Gardens, Kew. Interestingly, the enormous waterlily - that has been hiding in plain sight for over a century - was mistakenly identified as another species.

Identified as Victoria boliviana, the giant waterlily was previously mistaken for Victoria amazonica, the waterlily named after England’s Queen Victoria in 1837.

Now, a team of world experts in Science, Horticulture, and Botanical Art have scientifically proven in the journal Frontiers in Plant Science that Victoria boliviana is a new species to science using novel data and their unique mix of expertise, according to the Royal Botanic Gardens, Kew.

There are more surprises.

V. boliviana is now the largest waterlily in the world, with leaves reaching 3 meters (10 feet) wide in the wild! That would be about one-third as long as a London bus.

Currently, the record for the largest species is held by La Rinconada Gardens in Bolivia where leaves grew to 3.2 meters.

The species was grown in a glasshouse

The species is native to Bolivia where it grows in the Llanos de Moxos in the Beni province, one of the largest wetlands in the world. Though it produces many flowers a year, they open only in turn, one at a time, and just for two nights - turning from white to pink and covered in sharp prickles.

Carlos Magdalena, a world expert on waterlilies and one of Kew’s senior botanical horticulturists, along with his team Lucy Smith, a freelance Kew botanical artist, and Natalia Przelomska, a biodiversity genomics researcher, long suspected that the plant was different from the other two known giant species, Victoria amazonica and Victoria cruziana.

"Ever since I first saw a picture of this plant online in 2006, I was convinced it was a new species. Horticulturists know their plants closely; we are often able to recognize them at a glimpse. It was clear to me that this plant did not quite fit the description of either of the known Victoria species and therefore it had to be a third," Magdalena said in a news release.

He continued: "For almost two decades, I have been scrutinizing every single picture of wild Victoria waterlilies over the internet, a luxury that a botanist from the 18th, 19th, and most of the 20th century didn't have."

After making a few inquiries, scientists from Bolivia - from the National Herbarium of Bolivia, Santa Cruz Botanic Gardens, and Public Botanic Garden La Rinconada - donated some seeds to Kew.

A mind-blowing discovery

As Magdalena watched the waterlily grow next to the two other Victoria species, he immediately suspected that something was different. He noticed that Victoria boliviana had a different distribution of prickles and seed shape to other members of the Victoria genus, making it distinct.

He told BBC News: "It meant we could grow it side-by-side with the two other species under exactly the same conditions. Once we did this we could very clearly see that every single part of the plant was totally different."

Though some 2,000 new plant species are identified every year, it is rather unusual that a plant this size was only discovered now. 

Magdalena, who described the plant as "one of the botanical wonders of the world", told AFP: "It also highlights how many things could be out there. It really highlights how little we know in the end about our natural world."

Smith, who made scientific illustrations of all three species told the BBC that she had to head into the glasshouse at night because waterlily flowers only came out in the dark. "I was able to get access to the flowers, and also by looking at the leaves, I could, as an illustrator, highlight those differences that I saw," she said.

"And in fact, while I was drawing those differences, they became even stronger in my mind and I found new ways of telling them apart. Maybe I’m biased, but out of the three species I think [the new species] has one of the most beautiful flowers," she added.

A lack of data led to misidentification

A lack of data led to mislabelling the waterlily. In 1832, V. amazonica was the first species to be named in the genus but the data available wasn't sufficient - which led to a lack of comparisons against any new species found since. 

Therefore, the researchers were insistent to improve their knowledge of Victoria. The paper's authors compiled all available information using historical records, citizen science (including social media posts), and specimens from Herbaria and living collections around the world. Kew Scientists also analyzed DNA to show that V. boliviana was very genetically different from the other two species.

Altogether, the data collected confirmed what the authors long suspected – that there was another species in the Victoria genus, joining V. amazonica and V. cruziana.

"In the face of a fast rate of biodiversity loss, describing new species is a task of fundamental importance; we hope that our multidisciplinary framework might inspire other researchers who are seeking approaches to rapidly and robustly identify new species," said Przelomska.

The paper's authors chose the name Victoria boliviana "in honor of Bolivian partners and the South American home of the waterlily where it grows in the aquatic ecosystems of Llanos de Moxos."

Abstract:
Reliably documenting plant diversity is necessary to protect and sustainably benefit from it. At the heart of this documentation lie species concepts and the practical methods used to delimit taxa. Here, we apply a total-evidence, iterative methodology to delimit and document species in the South American genus Victoria (Nymphaeaceae). The systematics of Victoria has thus far been poorly characterized due to difficulty in attributing species identities to biological collections. This research gap stems from an absence of type material and biological collections, also the confused diagnosis of V. cruziana. With the goal of improving systematic knowledge of the genus, we compiled information from historical records, horticulture and geography and assembled a morphological dataset using citizen science and specimens from herbaria and living collections. Finally, we generated genomic data from a subset of these specimens. Morphological and geographical observations suggest four putative species, three of which are supported by nuclear population genomic and plastid phylogenomic inferences. We propose these three confirmed entities as robust species, where two correspond to the currently recognized V. amazonica and V. cruziana, the third being new to science, which we describe, diagnose and name here as V. boliviana Magdalena and L. T. Sm. Importantly, we identify new morphological and molecular characters which serve to distinguish the species and underpin their delimitations. Our study demonstrates how combining different types of character data into a heuristic, total-evidence approach can enhance the reliability with which biological diversity of morphologically challenging groups can be identified, documented and further studied.