By Jake Buehler
It’s night, and plant biologist Arthur Domingos de Melo is looking up at the open, ivory flowers of a tropical, hardwood tree. Though it’s the dry season in the arid, thorny Caatinga region of northeast Brazil, a slow drizzle begins to fall. But not from the sky. Domingos de Melo is under the tree’s canopy, and the “rain” is sweet.
Behold Hymenaea cangaceira, a species whose flowers make so much nectar that it overflows and falls in unusually copious and fragrant showers, even though the price of water in this part of the world is steep.
Domingos de Melo and colleagues at the Universidade Federal de Pernambuco in Recife, Brazil, had been studying bat pollination of local plants for two decades in the region when, in 2015, one type of bat-pollinated tree struck them as odd. Its nectar, rather than just the flower petals, was imbued with its own perfume — a phenomenon poorly understood in bat-pollinated plants — and the plant made loads of it.
From 2015 to 2018, the team studied a population of H. cangaceira in Brazil’s Catimbau National Park. Each day after sunset during the trees’ reproductive season, between December and March, hundreds of flowers bloom on each tree and drip with nectar before wilting with the dawn.