Ophioglossum thermale is
a miniature fern found in inland wetlands or dry riverbeds; the
rhizomes are thin and short and bear a few leaves in bundles. The
leaves, 5-20cm long; trophophylls are small, measuring 0.7-3cm in
length, 0.3-1cm in width, in the shape of ranging from a linear to
ovate, with the tips from acute to rounded; sporophylls
are 6-9cm in length.