Definition of pod fern in US English:

pod fern

noun

rare
  • A pantropical aquatic fern, Ceratopteris thalictroides (family Parkeriaceae), in which the rolled leaf margins of the fertile fronds enclose the spores to give the impression of a seed pod.

Origin

Mid 19th century; earliest use found in John Loudon (1783–1843), landscape gardener and horticultural writer.