Convergent evolution in arid environments is thought to be responsible for widespread homoplasy in the morphological characters traditionally used to classify this group.

Myriopteris can also be separated from Cheilanthes s.s., although less reliably, by spores bearing crests or wrinkles (rather than spines or bumps) and a lack of enlarged vein endings (rather than prominent hydathodes).

[1] The three subgroups of the genus, informally called the alabamensis, covillei, and lanosa clades, likewise lack unique defining features.

Fée, who separated it from Cheilanthes proper by the presence of red hairs among the sporangia and a scarious (hardened) indusium formed from the leaf margin.

John Smith recognized Myriopteris in his Cultivated Ferns of 1857, noting the "minute, orbicular or cuneiform, concave" ultimate segments typical of species in the genus.

Many of the morphological characters that have traditionally been used to separate the cheilanthoid ferns into genera, including Cheilanthes, are homoplasious; that is, they have appeared independently in unrelated groups, probably as a result of convergent evolution in arid environments.

[9] Further phylogenetic analysis by Eiserhardt et al., in the course of a study on cheilanthoid evolutionary radiation in the Cape Floristic Region, also supported the existence of the myriopterid clade and showed that Cheilanthes rawsonii, an African endemic, was deeply nested in it, its closest relative being C. parryi.

[14] The following species (including two hybrids) are those recognized by Grusz & Windham in 2013, with some additions from the Checklist of Ferns and Lycophytes of the World (version 18.3).

[18] The closely related species M. gracillima, M. intertexta, M. covillei, and M. clevelandii [19] all grow mostly in rock crevices, with western North American ranges that overlap in increasingly hot and dry climates.