Nuphar lutea (L.) Sm.

A herb. It grows in water. It keeps growing from year to year. The rhizomes or underground stems are stout and 3-8 cm across. The leaf stalk is about 50 cm long. The leaf blade floats but can also be above the water. It is oval and 15-30 cm long by 10-22 cm wide. It is leathery. It can be hairy underneath. The base is heart shaped and the lobes are spreading. The flowers are above the water level. They occur singly in the axils of leaves. The flowers are 4-5 cm across. There are 6 sepals with the outer ones being green and the inner yellow. The fruit stalk is about 50 cm long. The sepals are 2-3 cm long. The petals are narrow. They are small and many. The fruit are about 2.5 cm across. There are 5-20 united in a group. The seeds are olive green and 5 mm across.

It grows in temperate places. It grows in permanent water to about 1 m deep. It grows in lakes and ponds in Xinjiang in China. It suits hardiness zones 4-9.

The flowers are used to make a drink. The roots and leaf-stalks are eaten. They are boiled. It is also the source of starch. Seed kernels are parched or roasted and eaten with salt. They can be ground into flour for bread. Caution: The rhizomes contain a mildly poisonous substance called nupharine that is destroyed on cooking.

Plants can be grown from seed or by dividing the clump.