Cryptocoryne lingua

Cryptocoryne lingua is a water trumpet that grows to approximately 8-15 cm in height. Its somewhat succulent leaves are spatulate to ovate, 2 to 7 cm in length, 1 to 3.5 cm in width. Their upperside is waxy and smooth, and of a light green colour. The leaf stalk grows to 4 to 10 cm, and thus as long or longer than the leaf blade.
This species is found in the Malaysian part of Borneo (Sarawak) in the freshwater tidal zone of rivers near the coast. The populations of that plant are regularly flooded by the tides. Other than Cryptocoryne ciliata, which lives in similar habitats, no marine water reaches the locations where C. lingua is found, but only dammed-up freshwater. [1]

C. lingua sometimes is sold in the aquarium trade, however, it does not survive when cultivated constantly submersed and thus is not suitable as aquarium plant. It can be cultivated emersed, however, in loamy substrate. [1]