Asplenium

Asplenium is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other authors consider Hymenasplenium separate, based on molecular phylogenetic analysis of DNA sequences, a different chromosome count, and structural differences in the rhizomes. The type species for the genus is Asplenium marinum.

The most common vernacular name is spleenworts, applied to the more "typical" species. A. nidus and several similar species are called bird's-nest ferns, the Camptosorus group is known as walking ferns, and distinct names are applied to some other particularly well-known species.

Etymology

From New Latin ("spleenworts"), Linnaeus's adjustment of Latin ("spleenwort"), from Ancient Greek (, "spleenwort"), from ἀ- (a-, "un-") + (, "spleen") + -ον (-on, "-um"), from its use to cure anthrax in livestock.

Taxonomy and genetics

Many groups of species have been separated from Asplenium as segregate genera. These include Camptosorus, Ceterach, Phyllitis, and Tarachia, but these species can form hybrids with other Asplenium species and because of this are usually included in a more broadly defined Asplenium.

Some of the older classifications elevate the Aspleniaceae to the taxonomic rank of order as Aspleniales. The newer classifications place it in the subordinal group called eupolypods within the order Polypodiales. Within the eupolypods, Aspleniaceae belongs to a clade informally and provisionally known as eupolypods II.

It has been found that in some species, the chloroplast genome has evolved in complex and highly unusual ways. This makes standard cladistic analyses unsuited to resolve the phylogeny of that particular group of ferns, and even very sophisticated computational phylogenetics methods yield little information. In addition to hybridization running rampant in parts of this genus, there are also some species like the mother spleenwort (A. bulbiferum) or A. viviparum which mainly reproduce asexually, essentially cloning themselves over and over again. While most are diploid or tetraploid, some species (e.g. A. shuttleworthianum) are octoploid.

Uses

Both the scientific name and the common name "spleenwort" are derived from an old belief, based on the doctrine of signatures, that the fern was useful for ailments of the spleen, due to the spleen-shaped sori on the backs of the fronds. "-wort" is an ancient English term that simply means "plant" (compare German -wurz). The plants were thought to cause infertility in women.

Asplenium × kenzoi - oni-hinokishida, cultivated in Japan
Asplenium komarovii - Akasawa
Asplenium laciniatum
Asplenium lamprophyllum Carse
Asplenium laserpitiifolium – Johnston River fern
Asplenium lepidum C.Presl
Asplenium listeri – Christmas Island spleenwort
Asplenium longissimum
Asplenium lucidum
Asplenium lunulatum – Hen-and-chicks
Asplenium lyallii
Asplenium macedonicum
Asplenium majoricum
Asplenium marinum – sea spleenwort
Asplenium × microdon T Moore – Moore's spleenwort (hybrid between Asplenium scolopendrium and Asplenium obovatum subsp lanceolatum)
Asplenium milnei Carruth
Asplenium montanum – mountain spleenwort
Asplenium musifolium
Asplenium nidus – bird's-nest fern
Asplenium normale
Asplenium obliquum
Asplenium oblongifolium Colenso – shining spleenwort (= A. lucidum auct. non Burm.f., sensu G.Forst.)
Asplenium obovatum
Asplenium obtusatum G.Forst.
Asplenium obtusatum ssp. northlandicum (Brownsey) Ogle (possibly distinct species)
Asplenium obtusatum 'Chile' (possibly distinct species, sometimes included in A. obliquum)
Asplenium oligolepidum C.Chr. (= A. lucidum auct. non Burm.f., sensu G.Forst.)
Asplenium oligophlebium
Asplenium onopteris L. – western black spleenwort, Irish spleenwort (sometimes included in A. adiantum-nigrum)
Asplenium pacificum
Asplenium paleaceum R.Br. – chaffy spleenwort
Asplenium palmeri
Asplenium parvum
Asplenium petrarchae
Asplenium pinnatifidum – lobed spleenwort
Asplenium planicaule
Asplenium platybasis Kunze ex Mett.
Asplenium platyneuron – ebony spleenwort
Asplenium polyodon G.Forst. – sickle spleenwort
Asplenium praemorsum
Asplenium prolongatum Hook.
Asplenium pteridoides Baker
Asplenium resiliens – black-stemmed spleenwort
Asplenium rhizophyllum – American walking fern (sometimes in Camptosorus)
Asplenium richardii
Asplenium ruprechtii – Asian walking fern (sometimes in Camptosorus)
Asplenium ruta-muraria L. – wall-rue
Asplenium rutifolium
Asplenium sagittatum – Mule's spleenwort (sometimes in Phyllitis)
Asplenium sandersonii Hook.
Asplenium × sarniense Sleep Guernsey Spleenwort
Asplenium schizotrichum Copel.
Asplenium schweinfurthii
Asplenium scleroprium
Asplenium scolopendrium – hart's-tongue fern (sometimes in Phyllitis)
Asplenium scolopendrium var. americanum – American Hart's-tongue
Asplenium seelosii
Asplenium septentrionale – forked spleenwort, northern spleenwort
Asplenium septentrionale × trichomanes Wulf.
Asplenium serra
Asplenium serratum – wild bird's-nest fern
Asplenium sessilifolium
Asplenium shuttleworthianum Kunze
Asplenium simplicifrons F.Muell.
Asplenium splendens
Asplenium surrogatum P.S.Green
Asplenium tenerum G.Forst.
Asplenium terrestre
Asplenium theciferum (Kunth) Mett.
Asplenium thunbergii
Asplenium trichomanes – maidenhair spleenwort
Asplenium trichomanes ssp. quadrivalens D.E. Meyer
Asplenium trichomanes ssp. trichomanes
Asplenium trichomanes subsp. coriaceifolium
Asplenium trilobum Cav.
Asplenium tutwilerae B.R.Keener & L.J.Davenport
Asplenium unisorum (Wagner) Viane
Asplenium vespertinum
Asplenium vieillardii Mett.
Asplenium virens
Asplenium viride – green spleenwort
Asplenium vittiforme
Asplenium viviparum
Asplenium yoshinagae Makino

Etymology

Taxonomy and genetics

Uses

See also

References