It forms hybrids with a number of other spleenworts. The hybrid with mountain spleenwort (A. montanum) has been collected only rarely, but on multiple occasions, this hybrid has undergone chromosome doubling to give rise to the fertile species known as Bradley's spleenwort (A. bradleyi). A backcross between A. bradleyi and A. platyneuron is believed to have been collected once, from a now-destroyed site in Pennsylvania.[18] The hybrid with walking fern (A. rhizophyllum), known as Scott's spleenwort (A. × ebenoides) regularly appears where the two parent species grow together. At one locality, in Havana Glen, Alabama, A. × ebenoides has undergone chromosome doubling to produce a fertile species, Tutwiler's spleenwort (A. tutwilerae). The backcross between A. platyneuron and A. tutwilerae is known as Boydston's spleenwort (A. × boydstoniae), occurring in nature only with A. tutwilerae at Havana Glen, Alabama.[19] It is also known to hybridize with lobed spleenwort (A. pinnatifidum), a descendant of mountain spleenwort and walking fern, to produce the rare Kentucky spleenwort (A. × kentuckiense).

The preceding hybrids form part of the so-called "Appalachian Asplenium complex". A. platyneuron can also hybridize outside the complex with wall-rue (A. ruta-muraria), forming Morgan's spleenwort (A. × morganii), and with maidenhair spleenwort (A. trichomanes) to form Virginia spleenwort (A. × virginicum). [Wikipedia]

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