Microsorum pteropus on lava stone.
Microsorum pteropus is a water fern from Asia, 15-30 cm tall, which should be grown on a root or stone, attached with fishing line until it has gained a hold. If it is planted in the bottom, do not cover the rhizome because it will rot. Easy to propagate by splitting the horizontal rhizome. A hardy plant which grows in all conditions. The black spots under the leaves are sporangia (reproductive organs), not signs of disease as many believe.
Height 15 - 30+cm