Nymphaea Tetragona, also known as Pygmy Water-lily, is a perennial aquatic herb. Pygmy waterlily grows in small ponds, lakes or even in a container feature, as it will thrive in water as shallow as 15cm deep. Nymphaea Tetragona has cup-shaped white flowers that bloom from July to August. The flowers are pollinated by flies and beetles. The leaves are elliptic in outline and are green above and green or purplish below. The flowers have no scent. They have four green sepals, 8 to 15 white petals and 20 to 40 yellow stamens. The shade cast by the leaves helps to check the spread of the algae, and also provides shelter for aquatic insects and larvae, such as tadpoles. Pygmy Water-lily fails to regenerate in nature because of incomplete development of the embryos, and because of pests and diseases. As a result the population of this plant species is on the verge of extinction. The plant requires a rich soil and a sunny position. Hardiness zone: 3-12