Argyrochosma

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Argyrochosma
Argyrochosma jonesii 3.jpg
Argyrochosma jonesii
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Division: Polypodiophyta
Class: Polypodiopsida
Order: Polypodiales
Family: Pteridaceae
Subfamily: Cheilanthoideae
Genus: Argyrochosma
(Sm.) Windham
Species

See text.

Argyrochosma is a genus of ferns known commonly as false cloak ferns. The genus is included in the Cheilanthoideae subfamily of the Pteridaceae. [1] Species now in this genus were previously treated as members of related genera Notholaena or Pellaea but were segregated into their own genus in 1987. These ferns, of which there are about 20 species, are mostly native to the Americas, from North to South and including the Caribbean, while one species, A. connectens, is known from Sichuan, China. [2] They are commonly found growing in cracks between rocks. Their leaves are generally shorter than 40 centimeters and have rounded bluish or grayish green segments. Often the lower surface of the segments is coated in a white dust, and the sporangia contain brown spores.

Contents

Species

As of December 2021, the Checklist of Ferns and Lycophytes of the World recognized the following species: [3]

Related Research Articles

<i>Pellaea</i> (plant) Genus of ferns

Pellaea is a genus of ferns in the Cheilanthoideae subfamily of the Pteridaceae. The genus name is derived from the Greek word πελλος (pellos), meaning "dark," and refers to the brown stems. Many members of the genus are commonly known as cliffbrakes. They primarily grow in rocky habitats, including moist rocky canyons, slopes, and bluffs.

<i>Notholaena</i> Genus of ferns

Notholaena, cloak fern, is a genus of ferns in the Cheilanthoideae subfamily of the Pteridaceae. Ferns of this genus are mostly epipetric or occurring in coarse, gravelly soils, and are most abundant and diverse in the mountain ranges of warm arid or semiarid regions. They typically have a creeping or erect rhizome and leaves that are pinnatifid to pinnate-pinnatifid with marginal sori protected by a false indusium formed from the reflexed margin of the leaf. Members of Notholaena also have a coating of whitish or yellowish farina on the surfaces of the leaves. The farina is often limited to the abaxial (lower) leaf surface, but may occur on the adaxial (upper) leaf surface as well.

<span class="mw-page-title-main">Pteridaceae</span> Family of ferns

Pteridaceae is a family of ferns in the order Polypodiales, including some 1150 known species in ca 45 genera, divided over five subfamilies. The family includes four groups of genera that are sometimes recognized as separate families: the adiantoid, cheilanthoid, pteridoid, and hemionitidoid ferns. Relationships among these groups remain unclear, and although some recent genetic analyses of the Pteridales suggest that neither the family Pteridaceae nor the major groups within it are all monophyletic, as yet these analyses are insufficiently comprehensive and robust to provide good support for a revision of the order at the family level.

<i>Argyrochosma jonesii</i> Species of fern in the family Pteridaceae

Argyrochosma jonesii, known as Jones' false cloak fern, is a species of fern native to the southwestern United States and Sonora, Mexico. It grows on calcareous rocks, and has small, finely-divided leaves with a leathery texture and dark axes connecting the leaf segments. Unlike many members of Argyrochosma, it does not secrete white powder on the underside of its leaves. First described as a species in 1917, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

<i>Jamesonia</i> Genus of ferns

Jamesonia is a genus of ferns in the subfamily Pteridoideae of the family Pteridaceae. It now includes the formerly separate genus Eriosorus.

<span class="mw-page-title-main">Cheilanthoideae</span> Subfamily of ferns

Cheilanthoideae is one of the five subfamilies of the fern family Pteridaceae. The subfamily is thought to be monophyletic, but some of the genera into which it has been divided are not, and the taxonomic status of many of its genera and species remains uncertain, with radically different approaches in use as of December 2019.

<i>Argyrochosma nivea</i> Species of fern in the family Pteridaceae

Argyrochosma nivea is an Andean fern species in the genus Argyrochosma.

<i>Argyrochosma dealbata</i> Species of fern in the family Pteridaceae

Argyrochosma dealbata, the powdery false cloak fern, is a small fern endemic to the central and southern United States. It grows on calcareous rocks, such as limestone. Its leaves are highly divided, with leaf segments joined by shiny, chestnut-brown axes, and their undersides are coated with white powder, giving the fern its name. First described as a species in 1814, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

Argyrochosma connectens is a small cheilanthoid fern endemic to Sichuan, China. It is the only member of its genus known from Asia. Relatively rare, it is found growing in the crevices of limestone rocks in hot, dry valleys. The species was long classified in the genus Pellaea, but after a phylogenetic study in 2015 was transferred to Argyrochosma.

Argyrochosma peninsularis is a fern endemic to Baja California Sur. It grows in dry, rocky places. First described as a species in 1939, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns". A dusting of powdery material and the presence of occasional scales on the central axis of its leaves help distinguish it from related species.

Argyrochosma pallens is a fern endemic to Mexico. It has narrow, divided leaves with brown axes; the leaves are dusted with white powder above and coated in it below. First described as a species in 1956, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

Argyrochosma chilensis is a fern endemic to the Juan Fernández Islands off the coast of Chile. It has leathery, thrice-divided leaves with dark brown axes; the leaves are coated with white powder below. First described as a species in 1853, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

Argyrochosma stuebeliana is a fern endemic to Peru. Its highly divided, leathery leaves are coated with white powder on their under surface. Originally described as a variety of Argyrochosma dealbata in 1909, based on a single leaf collected by Alphons Stübel, whom its name honors, it was recognized as a distinct species in 1961, distinguished from similar members of the genus largely by its round leaf segments. It was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

Argyrochosma lumholtzii is a rare fern in the family Pteridaceae known from Sonora, Mexico. It is quite similar to Jones' false cloak fern, but has black leaf axes and a less highly divided leaf. First described as a species in 1939, honoring the explorer Carl Sofus Lumholtz, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

<i>Argyrochosma fendleri</i> Species of fern in the family Pteridaceae

Argyrochosma fendleri, Fendler's false cloak fern, is a fern known from the western United States and northwestern Mexico. It grows in rocky habitats, and is distinguished from other members of the genus by its zig-zag leaf axes. Like many species in the genus, it bears white powder on the underside of its leaves. First described as a species in 1851, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

Argyrochosma incana, the hairy false cloak fern, is a fern known from the southwestern United States through Mexico to Guatemala, and from a disjunct population in the Dominican Republic. It grows on rocky slopes and steep banks, often in forests. Like many of the false cloak ferns, it bears white powder on the underside of its leaves. First described as a species in 1825, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

Argyrochosma pilifera is a fern endemic to Mexico. It has lance-shaped, divided leaves with dark purple axes; the undersides of the leaves are coated in white powder. First described as a species in 1956, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

Argyrochosma formosa is a fern known from eastern and central Mexico and Guatemala. It grows on rocky slopes, particularly on limestone. Unlike many members of the genus, it lacks white powder on the underside of its leaves. First described as a species in 1842, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

<i>Argyrochosma limitanea</i> Species of fern in the family Pteridaceae

Argyrochosma limitanea, the southwestern false cloak fern, is a species of fern native to the southwestern United States and Sonora, Mexico. It grows on calcareous rocks, and has small, finely-divided leaves with a leathery texture, dark axes connecting the leaf segments, and a heavy coating of white powder on the undersurface. It reproduces apogamously; two subspecies are recognized, which may have originated independently through the hybridization of other taxa not yet discovered. First described as a species in 1919, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

<i>Argyrochosma microphylla</i> Species of fern in the family Pteridaceae

Argyrochosma microphylla, the small-leaf false cloak fern, is a species of fern native to New Mexico, Texas and northern Mexico. It grows on limestone rocks and cliffs, and has finely-divided leaves with small leaf segments, often folded in half when dry, which lack the white powder present on the leaf underside of many related species. First described as a species in 1869, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

References

  1. Christenhusz, Maarten J. M.; Zhang, Xian-Chun; Schneider, Harald (18 February 2011). "A linear sequence of extant families and genera of lycophytes and ferns" (PDF). Phytotaxa . 19: 7–54. doi:10.11646/phytotaxa.19.1.2. ISSN   1179-3163.
  2. Wang, Wan; Yang, Wenli; Mao, Xingxing; Zhao, Ranran; Dou, Ping; Zhang, Gangmin (16 July 2015). "The phylogenetic affinities of Pellaea connectens, a rare endemic Chinese fern". Phytotaxa. 220 (1): 30. doi:10.11646/phytotaxa.220.1.2.
  3. Hassler, Michael (5 December 2021), "Argyrochosma", World Ferns. Synonymic Checklist and Distribution of Ferns and Lycophytes of the World, 12.8, retrieved 2021-12-30

Further reading