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Alsophila is a genus of tree ferns in the family Cyatheaceae.[1] It has also been considered to be a section in the subgenus Cyathea of the genus Cyathea.
Species of Alsophila have a treelike growth habit, with an erect trunk that rarely branches, or sometimes a more shrublike habit, with a creeping stem. Their fronds are large, with a strawlike stalk (stipe), dark brown or black in colour. Brown or dark brown scales are present, with distinct margins. The blade (lamina) of the frond is divided one to three times (one- to three-pinnate). The sori (spore-producing structures) are rounded and borne on smaller veins on the lower surface of the frond. An indusium (a covering to the sori) may or may not be present; if present initially, it may be lost as the frond ages.[2]
Alsophila is now separated from the other genera in the family Cyatheaceae primarily on the basis of molecular phylogenetic studies.[1] The scales on the stalks (petioles) provide a morphological distinction. Alsophila has scales with distinct margins, unlike Sphaeropteris, and with an apical hair or spine (seta), unlike Cyathea. The ornamentation of the spores also distinguishes Alsophila and Cyathea.[3][4]
The genus Alsophila was erected by Robert Brown in 1810.[5] It is placed in the family Cyatheaceae.[1] The division of the family into genera has had a long and controversial history.[4] Three or four clades have been suggested based on molecular phylogenetic studies. The Pteridophyte Phylogeny Group classification of 2016 (PPG I) accepts three genera, placing the Gymnosphaera clade within Alsophila.[1] In 2018, Dong and Zuo proposed the relationship shown in the cladogram below, and provided names in Gymnosphaera for species they considered to belong in this genus.[6]
Cyatheaceae Alsophila sensu latoAlsophila sensu stricto
Gymnosphaera
Older sources, such as the New Zealand Organisms Register as of October 2000 and Large and Braggins (2004), place Alsophila within a broadly defined Cyathea.[7][8]
The Pteridophyte Phylogeny Group classification of 2016 (PPG I) accepted the genus Alsophila with 275 species.[1] As of July 2021, Plants of the World Online accepted 296 species.[9]
The genus Alsophila is native in tropical and subtropical areas, from North and South America, through Africa, Madagascar and tropical Asia, to eastern Australasia as far south as the subantarctic Auckland Islands.[9][2] It is found in moist montane forests, on slopes or in ravines, forming part of the lower canopy, middle understorey, or ground layers.[2]
Alsophila species all require frost-free or virtually frost-free, permanently moist, shaded conditions. Those which have been grown in Europe outside their native habitat include A. australis, A. cunninghamii, A. dealbata, A. leichhardtiana and A. rebeccae.[11] Other species are grown in their native regions. In Australia, A. australis is commonly grown and is a robust species, capable of tolerating some sun if kept in moist soil.[12] A. dregei is a popular garden plant in South Africa, with plants being collected for use from the wild sufficiently often to cause it to become extinct in some areas.[13]
The silver fern, Alsophila dealbata has become a widely recognised symbol of New Zealand, although it is not an official national symbol.[14]
In the 1971 comedy film A New Leaf, Henrietta Lowell (played by Elaine May) is a botanist whose dream is to classify a new species of fern. On a honeymoon trip, she indeed discovers a new species which she names Alsophila grahami after her new husband Henry Graham (Walter Matthau). She describes the plant as having a vestigial indusium.
Unfurling frond of Alsophila dealbata (silver fern) Alsophila is a genus of tree ferns in the family Cyatheaceae. It has also been considered to be a section in the subgenus Cyathea of the genus Cyathea.
Alsophila es una sección en el subgénero Cyathea. El nombre fue originalmente aplicado al género de helechos arbóreos y que ahora se consideran sinónimos con Cyathea.
Datos: Q17198593
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Especies: Alsophila (Cyatheaceae)
Alsophila es una sección en el subgénero Cyathea. El nombre fue originalmente aplicado al género de helechos arbóreos y que ahora se consideran sinónimos con Cyathea.
Le genre Alsophila regroupe des espèces de fougères arborescentes de la famille des Cyatheaceae. C'est un genre probablement synonyme au genre Cyathea.
Le genre Alsophila regroupe des espèces de fougères arborescentes de la famille des Cyatheaceae. C'est un genre probablement synonyme au genre Cyathea.
Alsophila est sectio subgeneris Cyatheae. Nomen ad genus Cyatheacearum primum adhibitum est quod idem generi Cyatheae nunc habetur.
Situs scientifici: Tropicos • GRIN • ITIS • NCBI • Biodiversity • Plant Name Index • Flora of China • USDA Plants Database 
Haec stipula ad biologiam spectat. Amplifica, si potes! Alsophila est sectio subgeneris Cyatheae. Nomen ad genus Cyatheacearum primum adhibitum est quod idem generi Cyatheae nunc habetur.
Alsophila is een botanische naam in de rang van geslacht. De naam is afgeleid uit het Grieks 'alsos' = "bos", 'phileein' = "bevriend zijn met".
Een geslacht onder deze naam wordt niet algemeen erkend. De planten die hier ingedeeld worden kunnen ook beschouwd worden als een ondergeslacht (Cyathea subg. Alsophila). In die opvatting zullen in het geslacht Cyathea niet alleen het geslacht Alsophila ingevoegd worden maar ook Hemitelia en Sphaeropteris.
Het gaat om circa twee- à driehonderd soorten in vochtige, tropische en warmgematigde gebieden. Het zijn typische boomvarens met een duidelijke stam en grote, dubbel of meermalen geveerde bladeren met vliezige schubben aan de bladsteel. De sori liggen aan de onderzijde van de bladeren op de nerven en bezitten geen indusium.
Bekende soorten uit dit geslacht zijn:
Alsophila eller Alsophilaslekten er en slekt av store tre-bregner; én av fire slekter innen den tropiske eller subtropiske familien Cyatheaceae innen ordenen Cyatheales. Det er om lag 270 kjente arter og en håndfull hybrider i denne slekten.
Disse bregnene vokser opprett og bare unntaksvis krypende. De oppstod i jura og er således svært gamle planter, men mange av dagens arter er atskillig yngre, fra tertiær.
Tre-bregnene er verdens største bregner. Bladene kan bli ettpar meter lange og har skjellaktig dekke i stedet for plantehår.
Nedenfor gjengis et utvalg av de om lag 270 artene i denne slekten:
Alsophila eller Alsophilaslekten er en slekt av store tre-bregner; én av fire slekter innen den tropiske eller subtropiske familien Cyatheaceae innen ordenen Cyatheales. Det er om lag 270 kjente arter og en håndfull hybrider i denne slekten.
Disse bregnene vokser opprett og bare unntaksvis krypende. De oppstod i jura og er således svært gamle planter, men mange av dagens arter er atskillig yngre, fra tertiær.
Tre-bregnene er verdens største bregner. Bladene kan bli ettpar meter lange og har skjellaktig dekke i stedet for plantehår.
