Cheilanthoideae | |
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Myriopteris parryi | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Polypodiales |
Family: | Pteridaceae |
Subfamily: | Cheilanthoideae W.C.Shieh |
Genera | |
Synonyms | |
Cheilanthaceae B.K.Nayar |
Cheilanthoideae is one of the five subfamilies of the fern family Pteridaceae. [1] [2] 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 [update] .
The following phylogram shows a likely relationship between Cheilanthoideae and the other Pteridaceae subfamilies. [3]
Pteridaceae |
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Although subfamily Cheilanthoideae itself is thought to be monophyletic, many of the genera into which it has been divided (including Cheilanthes, Doryopteris, Notholaena, and Pellaea) have been shown to be polyphyletic. [4]
The division of the subfamily Cheilanthoideae into genera and species remains uncertain as of December 2019 [update] . Christenhusz et al. (2011), the Pteridophyte Phylogeny Group classification of 2016 (PPG I), and the November 2019 version of the Checklist of Ferns and Lycophytes of the World (World Ferns 8.11) agree on the following genera: [1] [2] [5]
Some other genera that have been included in the subfamily (or split off from genera included in the subfamily) are: [1] [2] [5]
Other sources take a radically different approach. As of December 2019 [update] , Plants of the World Online places all of the possible genera of the Cheilanthoideae in the single genus Hemionitis. [7] (Parahemionitis is treated as a synonym of Acrostichum , [8] a member of a different subfamily.)
While much work remains to be done in delineating monophyletic genera in the cheilanthoids (Cheilanthes, Doryopteris and Pellaea remaining notably polyphyletic), several major clades have been consistently recovered in phylogenetic analyses and given informal names, as shown here:
cheilanthoids |
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The order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas.
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. Members of the related Pentagramma genus have a similar lower leaf-surface farina.
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.
Aleuritopteris is a genus of ferns in the Cheilanthoideae subfamily of the Pteridaceae. As with some other genera of the Cheilanthoideae, molecular phylogenetic studies have suggested that it is not monophyletic, and so may need to be circumscribed differently in future.
Argyrochosma is a genus of ferns known commonly as false cloak ferns. The genus is included in the Cheilanthoideae subfamily of the Pteridaceae. 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. They are commonly found growing in cracks between rocks. Their leaves are generally shorter than 40 cm (16 in) 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.
Llavea is a monotypic genus of fern in the family Pteridaceae. The sole species is Llavea cordifolia. It is often cultivated as an ornamental foliage plant. The genus was named in honour of Pablo de La Llave, a Mexican naturalist.
Bommeria is a genus of small pteridaceous rock ferns, native to the New World. Genetic analysis has shown it to be a stem offshoot clade of all the cheilanthoid ferns, except for Doryopteris, which is an even more basal ("primitive") stem offshoot. for years, it was assumed that this genus was closely allied with Hemionitis, but genetic analysis has shown that genus to be a more advanced genus evolutionarily. The same set of analysis has shown many presumed genera within this family to be paraphyletic, but the small genus Bommeria appears to be monophyletic, or a natural genus.
Polypodioideae is a subfamily belonging to the fern family Polypodiaceae, which is a member of the suborder Polypodiineae in the Pteridophyte Phylogeny Group classification of 2016 (PPG I). Alternatively, the subfamily may be treated as the tribe Polypodieae within a very broadly defined family Polypodiaceae sensu lato.
Vittarioideae is a subfamily of the fern family Pteridaceae, in the order Polypodiales. The subfamily includes the previous families Adiantaceae and Vittariaceae.
Cryptogrammoideae is a subfamily of ferns in the family Pteridaceae. The subfamily contains three genera and about 23 species.
Parkerioideae, synonym Ceratopteridoideae, is one of the five subfamilies in the fern family Pteridaceae. It includes only the two genera Acrostichum and Ceratopteris. The following diagram shows a likely phylogenic relationship between the two Parkerioideae genera and the other Pteridaceae subfamilies.
Pteridoideae is one of the five subfamilies of the fern family Pteridaceae. This subfamily contains about 14 genera and around 400 species.
Doryopteris is a genus of ferns in the subfamily Cheilanthoideae of the family Pteridaceae.
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.
The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish a consensus on the classification of pteridophytes that reflects knowledge about plant relationships discovered through phylogenetic studies. In 2016, the group published a classification for extant pteridophytes, termed "PPG I". The paper had 94 authors.
Hemionitis is a genus of ferns in the subfamily Cheilanthoideae of the family Pteridaceae. Its circumscription varies greatly in different systems of fern classification. In the Pteridophyte Phylogeny Group classification of 2016, it was one of more than 20 genera in the subfamily Cheilanthoideae, and was said to have five species. Other sources treat it as the only genus in the subfamily, and so accept about 450 species. With the restricted circumscription, species are native to tropical America.
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 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 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 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".