Local researchers are in a race to restore the “pygmy Rwandan water lily,” a species originally found exclusively in Rwanda, before going extinct in the country. Scientifically known as Nymphaea thermarum, it is the world's smallest water lily yet described. The plant's native habitat was damp mud formed by the overflow of a freshwater hot spring in Mashyuza, in Rusizi district. It became extinct in the wild about 10 years ago when local farmers began using the spring for agriculture, cutting off the flow of the spring, which dried up the tiny area—just a few square metres—that was the lily's entire habitat. Before the plants became extinct, German botanist Eberhard Fischer had sent some specimens to his country after realising that their habitat was so fragile. The plants were kept alive at the Bonn Botanic Gardens at the University of Bonn in Germany, but botanists could not solve the problem of propagating them from seed. Later on, the scientists figured out how to grow the waterlilies in an artificial environment. Speaking to The New Times, Elias Bizuru, a Professor of Life Sciences at the University of Rwanda (UR) and a research associate at the Centre of Excellence in Biodiversity and Natural Resource Management (CoEB), said the extinction of the waterlily was not only due to agriculture but also the activities of CIMERWA in the area. By 2020, the hot spring had dried, a development that was partly blamed on CIMERWA’s stone extraction activities. “Because the plants were surviving in the hot spring environment, they could not continue to exist when the hot spring had dried up. The water of the hot spring is different. It has many minerals that you cannot find in ordinary water,” he said. Currently, the pygmy lily can be found in botanical gardens in countries like the USA, England and Germany where scientists have managed to grow it under artificial conditions. Here, visitors have a chance to see the world’s smallest water lily. Professor Bizuru said that the local researchers are working to restore it in the country. “This is our country’s heritage. It does not have to be in other countries while it is extinct here. We have to restore it,” he noted. “We are looking for funding that can assist us to have it restored. We want to bring it back to its natural habitat in Bugarama, but we can as well introduce it to other places where we have hot springs in the country, for example Rubavu,” he added. Nymphaea thermarum forms rosettes 20 to 30 cm (7.9 to 11.8 in) wide, with bright green lily pads growing on short petioles. The very small flowers are white with yellow stamens, with the flowers held upright a few cm above the plant. They can self-pollinate, and after blooming the flower stalk bends so the fruit contacts the mud. The sepals are slightly hairy, and as large as the flower's petals. The plant is a tropical day bloomer displaying protogynous flowering patterns, opening early in the morning on the first day with female floral functioning, closing in early afternoon, and opening on the second day with male functionality.
