Nuphar lutea

Ecology

This aquatic plant grows in shallow water and wetlands, with its roots in the sediment and its leaves floating on the water surface; it can grow in water up to 5 metres deep. It is usually found in shallower water than the white water lily, and often in beaver ponds. Since the flooded soils are deficient in oxygen, aerenchyma in the leaves and rhizome transport oxygen to the rhizome. Often there is mass flow from the young leaves into the rhizome, and out through the older leaves. The rhizomes are often consumed by muskrats. The flower is solitary, terminal, held above the water surface; it is hermaphrodite, 2–4 cm diameter, with five or six large bright yellow sepals and numerous small yellow petals largely concealed by the sepals. Flowering is from June to September, and pollination is entomophilous, by flies attracted to the alcoholic scent. The flower is followed by a green bottle-shaped fruit, containing numerous seeds which are dispersed by water currents. The species is less tolerant of water pollution than water-lilies in the genus Nymphaea.

Taxonomy

Some botanists have treated Nuphar lutea as the sole species in Nuphar, including all the other species in it as subspecies and giving the species a holarctic range, but the genus is now more usually divided into eight species (see Nuphar for details).

Symbolism

Stylized red leaves of the yellow water lily, known as seeblatts or pompeblêden are used as a symbol of Frisia. The flag of the Dutch province of Friesland features seven pompeblêden.