Water hyacinth, is a distinctive floating plant that is suitable for indoor ponds and large open aquariums. It is also used as a summer plant in European garden ponds. Its size depends on the nutrients in the water and the light intensity. In open aquariums containing pure water it forms decorative miniature plants. It is now distributed all over the tropics and has become a menace, covering lake surfaces. In favourable conditions it forms an amazingly beautiful hyacinth-like flower.