Eichhornia natans

Eichhornia natans is a herbaceous aquatic plant mainly of West Africa, occasionally also of Tanzania and Madagascar.¹ Recorded sites in West Africa were fully sunlit pools and sluggish streams up to approx. 1 m deep.¹ Under water it bears sessile, linear leaves of 3–8 cm; vigorous plants also form heart-shaped floating leaves.¹

In the aquarium it is considered difficult: even with plenty of light the lower parts of the stem usually turn blackish; nutrient-rich, soft to medium-hard water and a nutritious substrate are recommended.¹ Without flowers it can hardly be told apart from E. diversifolia; its bluish-violet flowers have no yellow spot.¹² In one keeper's view, the plant grown in earlier years was mostly E. diversifolia; his own specimen is said to be largely orange even in ordinary lighting.³