Myriopteris covillei | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Polypodiales |
Family: | Pteridaceae |
Subfamily: | Cheilanthoideae |
Genus: | Myriopteris |
Species: | M. covillei |
Binomial name | |
Myriopteris covillei | |
Synonyms | |
|
Myriopteris covillei, formerly known as Cheilanthes covillei, [1] 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. [2]
Leaf bases are closely spaced along the rhizome, which is typically 2 to 4 millimeters (0.08 to 0.2 in) in diameter. [3] [4] It is covered with persistent scales about 2 millimeters (0.08 in) long, [5] which are linear to narrowly lanceolate, straight or slightly twisted, and tightly appressed (pressed against the surface of the rhizome). [3] They are a uniform dark brown to black in color, or in some cases have paler, narrow margins of a light brown color, [3] [4] [6] and lack marginal teeth. [6]
The fronds spring up in clusters; they do not unfold as fiddleheads like typical ferns (noncircinate vernation). When mature, they are 5 to 30 centimeters (2.0 to 12 in) long. [3] [5] The stipe (the stalk of the leaf below the blade) is 3 to 17 centimeters (1.2 to 6.7 in) long [6] and less than 2 millimeters (0.08 in) wide, [7] rounded on the upper surface, [3] dark brown [3] to dark reddish-brown in color. [6] It is covered with white to red-brown, lanceolate to linear scales. [6] [7]
The leaf blades are lanceolate to ovate-deltate in shape, [3] typically 1.5 to 5 centimeters (0.59 to 2.0 in) [3] [7] or even 6 centimeters (2 in) [7] wide and tripinnate to tetrapinnate (cut into pinnae, pinnules, pinnulets, and sometimes into divisions of pinnulets) at the base. [3] [7] The rachis (leaf axis) is rounded, rather than grooved, on its upper surface, dark in color, with some scales but no hairs. No distinct joint is present where the pinnae attach to the rachis, the dark color of the latter continuing into the base of the costa (pinna axis). [3] Each pinna is equilateral in shape, and the lowest pair of pinnae is not significantly enlarged compared to the others. [3] Aside from the dark base, the upper surface of the costae is green along much of their length. [3] The lower surface of the costae is covered in conspicuous scales. These are ovate-lanceolate in shape, and deeply cordate (notched at the base to appear heart-shaped). The largest scales are 0.4 to 1.5 millimeters (0.02 to 0.06 in) wide. The scales overlap each other, and sometimes conceal the final subdivisions of the leaf from below. Only the basal lobes of the scales are ciliate. [3]
This fern has dark to medium green leaves (fronds) which may be up to 4-pinnate (made up of leaflets that subdivide up to 3 times), such that the leaflets are layered with overlapping rounded segments. The leaves as a whole have a bumpy, cobbled look when viewed from above. The edges of the leaflets are curled under (forming a false indusium) and their undersides have wide scales which are lengthened outgrowths of the epidermis. Tucked under the scales and false indusium are the sporangia, which make the spores. [2] Myriopteris covillei can be distinguished from its very similar relative Myriopteris intertexta by the scales on the underside of the leaflets. These scales are up to 3 mm wide at their base in M. covillei, giving them an elongated triangular papery appearance, whereas those of M. intertexta are 1 mm wide, appearing more like a flattened thread. [2]
Coville's lip fern is native to California, Baja California, Arizona, Oregon, and Utah. [8]
It grows in rocky crevices in the mountains and foothills. In California it is found in chaparral, yellow pine forest, pinyon-juniper woodland, and Joshua tree woodland habitats. [2]
Myriopteris covillei was first described by William Ralph Maxon in 1918, as Cheilanthes covillei, based on material collected in the Panamint Range by Frederick Vernon Coville and Frederick Funston on the United States Department of Agriculture's Death Valley expedition in 1891. The epithet presumably honors Coville. [9] By a strict application of the principle of priority, Oliver Atkins Farwell transferred the species to the genus Allosorus as Allosorus myriophyllus var. covillei in 1931, that genus having been published before Cheilanthes . [10] Farwell's name was rendered unnecessary when Cheilanthes was conserved over Allosorus in the Paris Code published in 1956.
Rodolfo Pichi-Sermolli, in 1977, advocated the revival of the genus Myriopteris for a small group of species usually placed in Cheilanthes, [11] although this was not widely accepted by his contemporaries. [1] Áskell and Doris Löve, his collaborators in a cytotaxonomy-based revision of fern genera, [1] transferred C. covillei to this genus as Myriopteris covillei in the same year. [12]
The development of molecular phylogenetic methods showed that the traditional circumscription of Cheilanthes, including that used by Maxon, is polyphyletic. Convergent evolution in arid environments is thought to be responsible for widespread homoplasy in the morphological characters traditionally used to classify it and the segregate genera, such as Myriopteris, that have sometimes been recognized. On the basis of molecular evidence, Amanda Grusz and Michael D. Windham again advocated for the revival of Myriopteris in 2013, with a broader circumscription than that of Pichi-Sermolli and Löve & Löve, including M. covillei. [1]
In 2018, Maarten J. M. Christenhusz transferred the species to Hemionitis as H. covillei, as part of a program to consolidate the cheilanthoid ferns into that genus. [13]
Based on plastid DNA sequence, Myriopteris covillei is part of Myriopteris clade C (covillei clade) and is most closely related to Myriopteris clevelandii and Myriopteris gracillima. [14] In addition, Myriopteris covillei is one of the parents of the fertile allotetraploid Myriopteris intertexta . [15] [1] [14]
While globally apparently secure (G4), M. covillei is threatened in the northern part of its range. NatureServe considers it to be critically imperiled in Oregon, imperiled in Utah, and vulnerable in Nevada. [16]
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.
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 endemic to 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.
Myriopteris gracillima, formerly known as Cheilanthes gracillima, is a species of lip fern known by the common name lace lip fern. It is native to western North America, where it grows in rocky habitat from British Columbia to California to Montana.
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.
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.
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.
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.
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 maxoniana is a species of cheilanthoid fern endemic to the Mexican state of Tamaulipas. It is known only from one collection. It closely resembles Myriopteris longipila and was not described as a distinct taxon until 2004.
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 endemic to the Mexican state of Sonora, a member of the family Pteridaceae. It is known only from a single collection. 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 endemic to 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.
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.
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 wootonii, formerly known as Cheilanthes wootonii, is a species of fern in the Pteridaceae family with the common name Wooton's lace fern.
Myriopteris fendleri, formerly known as Cheilanthes fendleri, is a species of fern in the Pteridaceae family with the common name Fendler's lip fern. It is native to the southwest United States and northern Mexico.
Myriopteris lindheimeri, formerly known as Cheilanthes lindheimeri, is a species of fern in the Pteridaceae family with the common name fairy swords.
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.
Myriopteris mickelii is a fern endemic to southern Mexico. It is very similar to M. cinnamomea of Central America, from which it was separated when described in 1980, and to other species in the "alabamensis clade" of Myriopteris. Named after the pteridologist John T. Mickel, it grows on dry, lightly shaded slopes and banks.