Sebastian Kennerknecht / Hairy Water Lily (Nymphaea pubescens) flower, Diyasaru Park, Colombo, Sri Lanka

John Cancalosi / American bullfrog (Lithobates catesbeianus) swimming near Water lilies (Nymphaea sp) Washington DC, USA. July.

Jack Dykinga / Marshland with Water Lilies (Nymphaea sp) covering the surface of the water, San Luis Potosi, Mexico, Central America

Jim Brandenburg / Water Lily (Nymphaea sp) cluster in pond surrounded by coniferous forest, Boundary Waters Canoe Area Wilderness, Minnesota

Jim Brandenburg / Water Lily (Nymphaea sp) cluster in pond surrounded by coniferous forest, Boundary Waters Canoe Area Wilderness, Minnesota

Sebastian Kennerknecht / Hairy Water Lily (Nymphaea pubescens) flower, Diyasaru Park, Colombo, Sri Lanka

Cyril Ruoso / Water Lily (Nymphaea sp) flowers, Bangweulu Wetlands, Zambia

Jen Guyton / Park ranger wades across the floodplain holding a rifle, with water lilies (Nymphaea sp.) in the foreground. Gorongosa National Park, Mozambique, May 2017.

Michel Roggo / Water soldier (Stratiotes aloides) and Water lily (Nymphaea sp.) In channel of the Danube Delta, Romania May 2015 . Photographed for The Freshwater Project

Michel Roggo / Water lily (Nymphaea sp.) and other aquatic plants in a lake in the Danube Delta Biosphere Reserve, Romania May 2014 . Photographed for The Freshwater Project

Michel Roggo / Water lily (Nymphaea sp.) and other aquatic plants in a lake in the Danube Delta Biosphere Reserve, Romania May 2014 . Photographed for The Freshwater Project

Tony Wu / Grey heron (Ardea cinerea) wading among water lilies (Nymphaea sp.) to forage for food Kanagawa, Japan.