Microsorum pteropus Wood

Microsorum pteropus grown on wood.

Microsorum pteropus is an Asian aquatic fern, 15–30 cm tall. Grow on a root ball or stone, attaching it with fishing line until it becomes established. If planted on the bottom, do not cover the rhizome, as it will rot. It is easy to propagate by dividing the horizontal rhizome.
A hardy plant that thrives in all conditions. The black spots under the leaves are sporangia (reproductive organs), not signs of disease, as many believe.