A global phylogeny of
Asplenium published in 2020 divided the genus into eleven clades, which were given informal names pending further taxonomic study.
A. haughtonii belongs to the "
A. cordatum subclade" of the "
Schaffneria clade". The
Schaffneria clade has a worldwide distribution, and members vary widely in form and habitat. There is no clear morphological feature that unites the
A. cordatum subclade. The sister species of
A. haughtonii is
A. phillipsianum from
Socotra, and the two together are sister to the African
A. cordatum. These three are scaly ferns of dry habitats; the other two species in the subclade are sister to them, and are
walking ferns, with long undivided leaves and proliferating leaf tips. == Etymology ==