These fragrant flowering plants live as rhizomatous aquatic herbs in temperate and tropical climates in shallow water around the world. The family contains five genera with about 70 known species. Did you know that Aldo Leopold had a water lily named after him? Did you know that I almost fell out of a canoe photographing and getting a good smell of fragrant white water lilies? By the way, they smell kind of lemony.
Water lilies are as beautiful as they are useful. They help maintain the well-being of ponds and rivers where they live by absorbing nutrients in the water that would normally feed undesirable green plants, helping to keep the water clear and looking clean. Water lilies have proven especially effective in absorbing heavy metals from water and will also oxygenate the water to help keep fish and other aquatic critters healthy.
Water lilies have several adaptations that help them survive in water. They have big leaves that float on the surface of the water attracting lots of sunlight for photosynthesis. Unlike most dry land plants that have stomata (stomata open and close to allow the intake of carbon dioxide and the release of oxygen) on the underside of their leaves, water lilies have their stomata on the upper sides of their leaves along with a waxy cuticle that keeps top leaf surfaces as dry as possible; the undersides of their leaves have thorns to protect them against predators munching on them.
Water lilies are insect pollinated in elaborate fashion as described by Christian Boix. First, a fluid gets secreted that covers the center of the flower and its female parts. Insects, lured by the plants’ fragrance, land on the smooth, steeply angled petals causing pollinators to slip ’n slide into the fluid below. If the visiting insect had already visited a mature plant and come bearing pollen from another water lily, then the visiting pollen dissolves into the fluid and the water lily becomes fertilized. Some species of water lilies change color after being fertilized. By the next morning, fluid production has ceased, been absorbed, and is no longer even there. Pollen production now starts in earnest and with the fluid now gone, the visiting insects can now emerge and leave carrying new pollen from this now-fertilized water lily.
After pollination has taken place, the stem of the water lily starts recoiling slowly, bringing the flower underwater. Here, away from nibbling insects, the fruit starts developing into a spongy berry that contains masses of seeds, up to 2,000 seeds in each fruit. The seeds and seed pods are eaten by deer, moose, beaver and a variety of waterfowl.
When the seeds are ripe and ready to disperse, the fruit opens and releases its contents into the water current. Seeds float away aided by an aril (a rather clever floating device that contains air pockets to keep them buoyant). They can travel for miles in the current, or reach even further if they are eaten, digested, and dispersed by birds and other animals. Either way, they eventually become waterlogged, stuck in a muddy bank where they germinate into a new plant.
Lily pads interspersed with open water provide excellent fish habitat, invertebrate food, and spawning grounds, especially for pan fish and frogs. And the fleshy rhizomes are a common food source for muskrats.