Dryopteris wattsii is an unusual species in the genus owing to its epiphytic habit, and large rhizome provided with an elongate ventral meristele. It is endemic to northern Queensland, Australia, and known only from a few populations. The Reverend W.W. Watts originally described Revwattsia fragilis in 1915 as a Polystichum, presumably because of its perceived similarity to Rumohra adiantiformis, which was then also included in Polystichum. The species was later moved to the monotypic genus Revwattsia by D.L. Jones. Chloroplast DNA sequence data however demonstrate that it belongs with Dryopteris.

McKeown, M., Sundue, M. and Barrington, D.S., 2012. Phylogenetic analyses place the Australian monotypic Revwattsia in Dryopteris (Dryopteridaceae). PhytoKeys, (14), p.43.