Nymphaea nouchali caerulea, also named Nymphaea caerulea, Nymphaea capensis, Blue water lily, Lady Lily of the Nile, Egyptian Lotus, is a perennial aquatic plant from South Africa. One plant can spread over an area of about 1 meter. This lovely aquatic plant with sky-blue flowers is South Africa's most commonly grown indigenous water lily. The Blue water lily was sacred to the ancient Egyptians. The God of the blue water lily was Nefertem, Lord of Perfume.
The plant has its roots firmly in the mud and sends out long stems to which their leaves are attached. The big circular leaves are floating at the surface and the flowers above it. The leaves are large and flat, rounded or oval in shape with notched margins, up to 40 cm in diameter, and cleft almost to the centre where the petiole is attached. They are relatively short lived and are replaced regularly throughout the growing season. They start out as a soft shiny green. As they age, they develop light brown or purple splashes which eventually cover the leaf, leaving only the veins green. The margins are slightly rolled inwards toward the uppermost side which helps keep the blades afloat. The veins act like a structural support for the leaves. The upper leaf surface is coated with a smooth waxy cuticle, which gives it the appearance of being leathery and shiny.
The variety name caerulea refers to the sky blue colour of the flowers. The large, elegant blue flowers are held well above the water at the tip of a sturdy green stalk and appear almost constantly from Spring until the end of Summer, the plant blooms repeatedly. They are bisexual, with 4 sepals, green on the outside and white to blue on the inside, and many blue petals. The flowers open in early to mid-morning and close completely in late afternoon and stay closed all night. A fully open flower measures 15-20 cm across and each flower lasts for about four days. The flowers are sweetly fragrant.
A few days after the Water Lily flower is pollinated, the flower stem tightens in a spiralling spring to bring the flower head underwater. The fruit develops underwater into a spongy berry with many seeds that are enclosed in arils. When ripe, many seeds are released from each fruit. Young seeds float as they contain air pockets. They are then dispersed by water currents or by water birds that eat them. As they become waterlogged, they sink into the mud to germinate. The plant also spreads by sprouting from the creeping rhizomes.
Hardiness zones 10-11, (1°C/35°F, 4°C/40°F) in Winter. Not very Winter hardy. Loves full sun but can grow in partial shade. It need very high moisture. The Lotus grows best in rich soil with 1/2 inch of rinsed gravel on top of the soil. The pot is completely submerge in calm freshwater.