Myriopteris is a genus of ferns in the family Pteridaceae, comprising roughly 43 accepted species as of mid-2025. Members are widely known as lip ferns — a name they share with the closely related Cheilanthes, referring to the lip-like false indusia that fold inward over the marginal sporangia. The genus name itself is built from the Greek myrio- ("very many") and pteris ("fern"), a nod to the densely divided fronds and the multitude of small, often bead-like ultimate segments that characterize many species.
Plants in this genus typically produce finely dissected leaves with very small pinnules, frequently arranged like rows of tiny beads along the rachis — a trait expressed in roughly 40% of species. Foliage is commonly clothed in hairs, scales, or both, and the precise pattern of indument is one of the principal characters used to separate species. Most members are small to medium-sized rock ferns of distinctly drought-adapted habit, with leathery or curling fronds that can shrivel during dry periods and rehydrate after rain.
The genus is centered on the New World. Its diversity is greatest in Mexico, but the overall range stretches from southwestern Canada south to southern Chile, with strong representation across the arid southwestern United States — Arizona, New Mexico, California, and Texas hold many of the best-known species. A single outlier, Myriopteris rawsonii, is endemic to Namibia and South Africa, the only confirmed African member of the genus.
Although Fée first described Myriopteris in 1852, the name spent most of the 20th century subsumed within a broadly circumscribed Cheilanthes. Molecular phylogenetic work in the early 21st century showed that traditional Cheilanthes was paraphyletic, comprising at least four distinct lineages. In 2013, Grusz and Windham formally revived Myriopteris to accommodate one of those clades — principally New World species — and many former Cheilanthes names were transferred into the resurrected genus. Some taxonomic databases (notably GBIF) still cross-list Myriopteris relative to Hemionitis, reflecting ongoing debate over generic limits within the cheilanthoid ferns.
Ecologically, these are quintessential xerophytic ferns. They grow on rocks or thin soil, often wedged into crevices on cliffs, boulders, and rock outcrops in hot, dry climates. This rock-loving, drought-tolerant habit sets Myriopteris apart from the moisture-loving ferns most gardeners picture, and explains why so many species cluster in the desert ranges of the American Southwest and Mexican highlands.
Etymology
The genus name Myriopteris combines the Greek myrio-, meaning "very many," with pteris, meaning "fern." Together they describe the numerous small, often bead-like ultimate segments that adorn the densely divided fronds typical of the genus. The English common name "lip ferns" — used for both Myriopteris and the related Cheilanthes — refers instead to the lip-like false indusia formed by the recurved leaf margins that fold inward to protect the sporangia along the underside of the pinnules.
Distribution
Myriopteris is overwhelmingly a New World genus. Its center of diversity lies in Mexico, and its overall range extends from southwestern Canada south through the western United States, Mexico, Central America, and the Andes to southern Chile. The arid southwestern United States — particularly Arizona, New Mexico, California, and Texas — hosts many of the best-known species, including M. clevelandii, M. cooperae, M. covillei, M. fendleri, M. gracilis, M. parryi, and M. wrightii. One species, M. rawsonii, breaks the pattern entirely: it is endemic to southern Africa, occurring in Namibia and South Africa, and is the only confirmed African member of the genus.
Ecology
Species of Myriopteris are characteristic xerophytic, rock-dwelling ferns. They occupy dry habitats, growing on rocks or thin soil, and many specialize in crevices on cliffs, boulders, and rocky outcrops. This rupicolous habit is closely tied to the genus's strong association with hot, arid climates — particularly the deserts and dry highlands of the American Southwest and Mexican plateau. Drought tolerance, leathery or hair-covered fronds, and an ability to dry down and rehydrate make these ferns conspicuous components of fern floras in environments where most other ferns cannot persist.
Taxonomy notes
Myriopteris was first described by A.L.A. Fée in 1852, with Myriopteris marsupianthes as the type species, but the name fell into disuse during much of the 20th century when its species were absorbed into a broadly circumscribed Cheilanthes. Molecular phylogenetic studies later demonstrated that traditional Cheilanthes is highly paraphyletic, splitting into at least four generically distinct clades; in 2013 Grusz and Windham resurrected Myriopteris to accommodate one of these lineages, made up principally of New World species. GBIF places the genus in family Pteridaceae, order Polypodiales, class Polypodiopsida, and notes that some treatments have synonymized Myriopteris under Hemionitis — a competing generic concept that has yet to be universally adopted. Chromosome counts give a base number of x = 30 for most species, with members of the alabamensis clade showing x = 29.
History
Although established by Fée in 1852, Myriopteris spent more than a century as a little-used name while its species were placed in Cheilanthes. The early 21st century saw a wave of taxonomic restructuring among the cheilanthoid ferns: molecular evidence drove the splitting of Cheilanthes into multiple genera, with many New World species moving into the newly described Gaga and the revived Myriopteris. The 2013 reinstatement by Grusz and Windham brought Myriopteris back into active botanical use, where it now houses roughly 43 species.
Conservation
The Global Invasive Species Database holds no record for Myriopteris, indicating that no member of the genus has been flagged as an invasive of international concern. Genus-level Red List, NatureServe, or regional protection status was not located in the consulted sources; individual species may carry separate conservation assessments not summarized here.
