Myriopteris

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Myriopteris
Cheilanthes wootonii (beaded lip fern) (6744464787).jpg
Myriopteris wootonii , showing the highly-divided leaves and beadlike segments associated with the genus
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Division: Polypodiophyta
Class: Polypodiopsida
Order: Polypodiales
Family: Pteridaceae
Subfamily: Cheilanthoideae
Genus: Myriopteris
Fée
Type species
Myriopteris marsupianthes
Fée
Species

See text.

Synonyms

Myriopteris, commonly known as the lip ferns, is a genus of cheilanthoid ferns. Like other cheilanthoids, they are ferns of dry habitats, reproducing both sexually and apogamously. Many species have leaves divided into a large number of small, bead-like segments, the probable inspiration for the generic name. Hairs and/or scales are often present on both the upper and lower surfaces of the leaf, and their presence and appearance are useful in distinguishing between species. The genus is most diverse in Mexico, but species are found from southwestern Canada south to southern Chile, and one species is endemic to southern Africa.

Contents

Description

No single morphological character divides Myriopteris, as presently circumscribed, from the other cheilanthoids. Convergent evolution in arid environments is thought to be responsible for widespread homoplasy in the morphological characters traditionally used to classify this group. [1] While small, bead-like ultimate segments are associated with the genus, they only appear in about 40% of its species, [2] and appear in some cheilanthoids outside the genus as well. Cheilanthessensu stricto bears 32 spores per sporangium in sexual species and 16 in apogamous species; with the exception of a few species of Notholaena , Myriopteris and the other cheilanthoids bear 64 spores per sporangium when sexual and 32 per sporangium when apomictic. Myriopteris can also be separated from Cheilanthess.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. The small, bead-like ultimate segments are found in the core subclade of the covillei clade and also in M. gracilis , which is deeply nested in the alabamensis clade. [3] Circinate vernation (the unfolding of new leaves as fiddleheads) is found throughout the lanosa clade and also in M. wrightii , the most basal member of the alabamensis clade. [3] Most species have round rachises, although early diverging members of the alabamensis and lanosa clades have rachises deeply grooved on the upper surface and flattened rachises shallowly grooved near the frond tip, respectively. [2] Leaf indument (hairs and scales) is highly diverse across the genus and a key feature in species identification. [2]

Myriopteris covillei has large, prominent scales beneath the leaf. Cheilanthes covillei 6.jpg
Myriopteris covillei has large, prominent scales beneath the leaf.
Myriopteris gracillima growing on basalt in the lower Columbia River gorge, WA Myriopteris gracillima IMG 3892 crop.jpg
Myriopteris gracillima growing on basalt in the lower Columbia River gorge, WA

The base chromosome number for the genus appears to be x=30, except for a portion of the alabamensis clade, where x=29; the latter is typical for other cheilanthoids. Most species are either sexually reproducing diploids or apogamous triploids, with the exception of M. lendigera and some specimens of M. microphylla and M. scabra , which are sexually reproducing tetraploids. [4]

Taxonomy

The genus was first described in 1852 by A.L.A. 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. He typified it on Myriopteris marsupianthes . Fée described the division of the leaf into numerous small, beadlike segments, all capable of bearing spores, [5] which may have led him to choose the name Myriopteris; "myrio-" means "very many" [6] and "pteris" means "fern". 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. [7] However, most authors until the 21st century preferred to include the genus in Cheilanthes. [8]

The development of molecular phylogenetic methods showed that the traditional broad circumscription of Cheilanthes is polyphyletic. 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. [1]

A molecular phylogeny of 157 cheilanthoid species by Michael D. Windham et al. in 2009 revealed seven well-supported clades within the group. One of these included a number of mostly North American species usually placed in Cheilanthessensu lato. They informally referred to this group as the myriopterids, Myriopteris being the most senior genus whose type specimen was included in the clade. [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 . [10] After more extensive sampling within the clade, Amanda Grusz and Windham revived Myriopteris in 2013 and provided names in it for all species in the myriopterid clade. [1]

Further molecular studies by Grusz et al. confirmed the monophyly of this group and showed that its species can be divided among three well-supported clades. These were informally referred to by the epithet of a prominent species in the clade, without formal taxonomic rank; they are the alabamensis clade (A), covillei clade (C), and lanosa clade (L). [11]

The genus Cheilosoria was described by Conde Vittore Trevisan in 1877 to accommodate Cheilanthes allosuroides, now M. allosuroides , and a few other species of Cheilanthes with long sori along the veins and relatively unmodified false indusia. [12] That genus was lectotypified on C. allosuroides by Edwin Copeland in 1947. [13] If the alabamensis clade were to be treated as a separate genus, Cheilosoria would be the senior name for it. [14]

Species

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). [15] Letters in parentheses following the scientific names indicate which of the three clades the species belong to, if known.

Distribution and habitat

Myriopteris parryi growing in a rock outcrop in Death Valley. Cheilanthes paryii.jpg
Myriopteris parryi growing in a rock outcrop in Death Valley.

The greatest diversity of species occurs in Mexico. [16] Myriopteris species are mostly confined to the Americas, ranging from southwestern Canada [17] to southern Chile. M. rawsonii is endemic to Namibia and South Africa. [16] It is most closely related to M. parryi , [10] a species of the Sonoran and Mojave Deserts. [4]

Like other cheilanthoids, Myriopteris species occupy dry habitats, growing on rocks or soil. [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. [20]

Notes and references

Related Research Articles

<i>Myriopteris covillei</i> Species of fern

Myriopteris covillei, formerly known as Cheilanthes covillei, is a species of cheilanthoid fern known by the common name Coville's lip fern. Coville's lip fern is native to the southwestern United States and Mexico.

<i>Myriopteris clevelandii</i> Species of fern

Myriopteris clevelandii, formerly known as Cheilanthes clevelandii, is a species of lip fern known by the common name Cleveland's lip fern. It is native to southern California and Baja California in Mexico. The leaf is divided into small, bead-like segments densely covered with scales beneath. In M. clevelandii, some of these scales are reduced to hairlike structures, which help distinguish it from the closely related M. covillei. It is usually found growing on exposed rock, particularly igneous rock.

<i>Myriopteris gracilis</i> Species of fern

Myriopteris gracilis, formerly known as Cheilanthes feei, is a species of lip fern known by the common name slender lip fern or Fee's lip fern.

<i>Myriopteris cooperae</i> Species of fern

Myriopteris cooperae, formerly Cheilanthes cooperae, is a species of lip fern known by the common name Mrs. Cooper's lip fern, or simply Cooper's lip fern. Its leaves grow in clusters and are highly dissected into oblong segments, rather than the beadlike segments found in some other members of the genus. The axes of the leaves are dark and covered in long, flattened hairs. It is only known from California, where it grows in rocky habitats, usually over limestone. The species was named in honor of its collector, Sarah Paxson Cooper; according to Daniel Cady Eaton, who described it in 1875, it was the first fern species to be named for a female botanist.

<i>Myriopteris intertexta</i> Species of fern

Myriopteris intertexta, formerly Cheilanthes intertexta, is a species of lip fern known by the common name coastal lip fern. It is native to montane California and western Nevada, Oregon east of the Cascades, and with a disjunct population in central Utah. It grows in dry rocky habitats in sun, typically in rock cracks with little or no soil.

<i>Myriopteris newberryi</i> Species of fern

Myriopteris newberryi, formerly Cheilanthes newberryi, is a species of lip fern known by the common name Newberry's lip fern. It is native to southern California and Baja California.

<i>Myriopteris tomentosa</i> Species of fern

Myriopteris tomentosa, formerly known as Cheilanthes tomentosa, is a perennial fern known as woolly lipfern. Woolly lipfern is native to the southern United States, from Virginia to Arizona and Georgia, and Mexico.

<i>Myriopteris myriophylla</i> Species of fern

Myriopteris myriophylla, the Central American lace fern, is a species of lip fern. Despite its common name, this species is native as far south as Argentina. It is adapted to dry areas.

<i>Myriopteris lanosa</i> Species of fern

Myriopteris lanosa, the hairy lip fern, is a moderately-sized fern of the eastern United States, a member of the family Pteridaceae. Its leaves and stem are sparsely covered in hairs, but lack scales, hence its common name. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows in shallow, dry, soil, often in rocky habitats.

<i>Myriopteris alabamensis</i> Species of fern

Myriopteris alabamensis, the Alabama lip fern, is a moderately-sized fern of the United States and Mexico, a member of the family Pteridaceae. Unlike many members of its genus, its leaves have a few hairs on upper and lower surfaces, or lack them entirely. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes as Cheilanthes alabamensis until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows in shade on limestone outcrops.

Myriopteris aemula, the Texas lip fern or rival lip fern, is a moderately-sized fern of Texas and Mexico, a member of the family Pteridaceae. Unlike many members of its genus, its leaves have a few hairs on upper and lower surfaces, or lack them entirely. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes as Cheilanthes aemula until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows on limestone rock.

Myriopteris yatskievychiana is a small fern native to Mexico, a member of the family Pteridaceae. It is known only from a single collection in the Mexican state of Sonora. While superficially similar to golden lip fern, a widespread species in Mexico, differences in its coating of hairs and its small size make it distinctive. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes.

Myriopteris allosuroides is a moderately-sized fern of Mexico, a member of the family Pteridaceae. Unlike many members of its genus, its rachides are grooved on the upper surface and largely free of hairs or scales. One of the cheilanthoid ferns, it was usually classified in the genera Cheilanthes or Pellaea until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows on dry, rocky slopes over acidic, particularly basaltic, rock.

<i>Myriopteris aurea</i> Species of fern

Myriopteris aurea, the golden lip fern or Bonaire lip fern, is a moderately-sized fern native to the Americas, a member of the family Pteridaceae. Unlike many members of its genus, its leaf is only modestly dissected into lobed leaflets (pinnae), which are hairy both above and below. One of the cheilanthoid ferns, until 2013 it was classified in the genus Cheilanthes as Cheilanthes bonariensis, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows on dry, rocky slopes, and ranges from Mexico, where it is common and widespread, and the southwestern United States south and east through Central and South America as far as Chile and Argentina.

<i>Myriopteris rufa</i> Species of fern

Myriopteris rufa, commonly known as Eaton's lip fern, is a moderately-sized fern of Mexico and the southwestern United States, with outlying populations in Costa Rica and the Appalachian Mountains. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes, as Cheilanthes eatonii, until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows in rocky habitats, most frequently on limestone but also sometimes on basalt or shale.

Myriopteris longipila, formerly known as Cheilanthes longipila, is a species of fern native to Mexico. It is characterized by a dense covering of long whitish hairs.

<i>Myriopteris rawsonii</i> Species of fern

Myriopteris rawsonii, formerly known as Cheilanthes rawsonii, is a perennial fern native to Namaqualand in Southern Africa. Like many other cheilanthoid ferns, it is adapted to dry conditions, bearing a thick layer of pale hairs on the underside of its pinnate-pinnatifid leaves. It is the only African representative of its clade of cheilanthoids, the otherwise American genus Myriopteris. It spends much of the year in a dried-out, dormant state, rehydrating and putting out new growth during winter rains. Its name honors the botanist and civil servant Sir Rawson W. Rawson.

<i>Myriopteris yavapensis</i> Species of plant

Myriopteris yavapensis, formerly known as Cheilanthes yavapensis, is a species of cheilanthoid fern with the common name Yavapai lip fern native to the southwest United States.

Myriopteris chipinquensis is a fern endemic to Mexico, a member of the family Pteridaceae. One of the cheilanthoid ferns, it was classified in the genus Cheilanthes until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It grows in oak-pine forests of the Sierra Madre Oriental, often with the very similar and closely related Myriopteris tomentosa.

Myriopteris cinnamomea is a Central American fern. It is very similar to M. mickelii of southern Mexico and to other species in the "alabamensis clade" of Myriopteris. It is modestly sized, with leaves not more than 30 centimeters (12 in) long. They are divided into pinnae, which in turn are divided into lobed pinnules, and covered with pale brown hairs on the underside.

References

  1. 1 2 3 4 Grusz & Windham 2013, pp. 53–54.
  2. 1 2 3 Grusz et al. 2014, p. 709.
  3. 1 2 Grusz et al. 2014, p. 705.
  4. 1 2 Grusz et al. 2014, p. 708.
  5. Fée 1852, p. 152.
  6. Short & George 2013, p. 213.
  7. Smith 1857, p. 28.
  8. Grusz & Windham 2013, p. 53.
  9. Windham et al. 2009, pp. 128–131.
  10. 1 2 Eiserhardt et al. 2011, p. 1274.
  11. Grusz et al. 2014, pp. 702, 704.
  12. Trevisan 1877, p. 579.
  13. Copeland 1947.
  14. Grusz & Windham 2013, p. 52.
  15. Hassler, Michael & Schmitt, Bernd (November 2019). "Myriopteris". Checklist of Ferns and Lycophytes of the World. 8.11. Retrieved 2020-01-01.
  16. 1 2 Grusz & Windham 2013, p. 55.
  17. Kartesz 2014.
  18. Grusz & Windham 2013, p. 54.
  19. Grusz et al. 2014.
  20. Jepson Flora Project (eds.) 2022, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on September 20, 2022

Works cited