Nymphaeales

Nymphaeales, the water lily order of flowering plants, containing 3 families, 6 genera, and 74 species. Members of the order are found in quiet freshwater habitats throughout most of the world. The aesthetic appeal of the water lilies, especially those of the genus Nymphaea, has led to their worldwide cultivation.

Nymphaeaceae (including the former family Barclayaceae), the water lily family, has 3 genera and 58 species. Cabombaceae, or the water shields and fanworts, is a closely related family with 2 genera, Cabomba and Brasenia. The last family, Hydatellaceae, contains 1 genus (Hydatella) and 12 species.

Amazon water lily

All plants of the Nymphaeales order are aquatic. They are attached to pond or stream bottoms, but whether their leaves and flowers are submerged, floating, or standing above the water varies. They range in size from the small, fragile Cabomba (fanwort), which has floating leaves less than 0.3 cm (1 inch) in diameter, to Nymphaea, which produce leaves 50 cm (about 18 inches) wide that can cover an area 2.5 metres (8 feet) in diameter in one summer. The largest water lily has impressive circular floating leaves that attain 2 metres (6.5 feet) in diameter and flowers 40 cm (about 15 inches) across.

water lilies

Many members of the order are suited for pools, aquatic gardens, and aquariums, where they are prized for their attractive foliage and showy flowers. The submerged leaves, the starchy, horizontal creeping rhizomes, and the protein-rich seeds of the larger species have been used as food by humans throughout history. The petioles (leaf stalks) serve as cover for fish and holdfasts for their spawn, and hoofed wildlife also browse on the plant parts. The emergent leaves provide cover for aquatic birds, and the seeds of many species are food for fish and fowl. Because they grow rapidly and can clog lakes, several members of Nymphaeales provide an essential link in plant succession—from pond to swamp to wet prairie.