Nymphaea rubra, Pink Water lily seeds

Nymphaea rubra seeds

Nymphaea rubra belongs to the family of the Nymphaceae. It is native to Thailand, India and the Nile delta. It is cultivated in Europe as an aquarist plant. The leaves show the so called heterophyllie, which means that the leaves that are under the water surface look different than those which are on the water surface. First of all the redish leaves under the watersurface develop. They are heart shaped, acute and the petiole grows nearly in the middle of the lamina. The leaves on the water surface are first redish than dark green and dentate at the leaf edge.
The flowers are red with 15 cm in diameter. If one does not like to have flowers one has to remove the leaves on the surface. The plant then builds more leaves under the surface. The flowers open at night and close again in the morning. This occurs only on 4 days. The flowers show proterogyny which means that first of all the female organs get fertile and on the next day the pollen is released. This inhibits self fertilization and promotes outcrossing.
The fruit gets ripe under water. It is brown green and reaches 4 to 6 cm in diameter. The seeds are elliptic, black and get just 1, 8 mm long. The seeds are surrounded by an arrilus, it includes air and so the seeds are able to swim. They are dispersed by wind or stream and when the arrilus is destroyed it sinks to the ground for germination. The roots are rhizomes which is good for rooting in the muddy ground. It can built stolones.

Cultivation
N. rubra needs a basic water pH of 6 to 8. The water temperature should be between 22°C and 30°C.