| Asplenium australasicum | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | Polypodiophyta |
| Class: | Polypodiopsida |
| Order: | Polypodiales |
| Suborder: | Aspleniineae |
| Family: | Aspleniaceae |
| Genus: | Asplenium |
| Species: | A. australasicum |
| Binomial name | |
| Asplenium australasicum | |
Asplenium australasicum, the bird's nest fern or crow's nest fern, is an epiphytic Australasian species of fern in the family Aspleniaceae. [1]
Asplenium australasicum was originally described by English botanist John Smith in 1857 as Neottopteris australasica. [2] He had reclassified the already known A. nidus in its own genus Neottopteris. Other botanists reclassified the genus as a section, Thamnopteris, within the genus Asplenium , [3] and William Jackson Hooker gave it its current binomial name in 1859. [4] Although the section Thamnopteris is distinctive, defining the species has been difficult as the morphology of the plants is so simple. [3] A. australasicum has been confused with (and called) A. nidus, [5] and Japanese populations which were considered to be A. australasicum by their morphology have been found to be genetically distinct and reclassified as a new species, A. setori . [3]
A global phylogeny of Asplenium published in 2020 divided the genus into eleven clades, [6] which were given informal names pending further taxonomic study. A. australasicum belongs to the "Neottopteris clade", [7] members of which generally have somewhat leathery leaf tissue. While the subclades of this group are poorly resolved, several of them share a characteristic "bird's-nest fern" morphology with entire leaves and fused veins near the margin. [8] Both the 2020 study [8] and a 2015 molecular study found that A. australasicum is polyphyletic, meaning that some populations were not closely related to others—A. australasicum from Fiji and Vanauatu were not closely related to A. australasicum from Australia and New Caledonia. Hence a revision with sampling of the species across its range was required to delineate the taxon and identify cryptic species. [9] A. australasicum forms a clade with the morphologically similar A. nidus sensu lato , but other bird's-nest ferns such as A. antiquum and A. phyllitidis form a separate subclade which is not particularly closely related. [7]
Asplenium australasicum grows as shrubby plant, with a rosette of yellow-green fronds which are 60 to 80 cm (24–32 in) long and 3 to 21 cm (1.2–8.4 in) wide. [10] It can be distinguished from A. nidus by its prominent midrib under its fronds, giving the fronds a keeled appearance. [3] The spores form in parallel lines which run in parallel with the veins and oblique to the midrib. [5]
A. australasicum grows on rocks or as an epiphyte on trees and is native to eastern New South Wales and Queensland. [10] The clumps can reach a large size, with the centre of the fern acting as a reservoir for debris. [5] The colonial botanist William Woolls wrote "... as a caution to fern gatherers, sometimes a species of black snake coils itself up in the centre" (of the birds nest fern). [11]
Asplenium australasicum specimens were taken from logged areas, which helped them become popular in horticulture. [5] It adapts readily to cultivation, as long as it has good drainage. Poor drainage renders it vulnerable to rotting. [12] It can be grown in a tub or barrel. [1] In cultivation it is occasionally attacked by white coconut scale on the underside of the fronds. [1]
Apart from its use as an ornamental plant, bird's nest fern is also a popular vegetable in Taiwan, particularly in the Eastern part of the island, where the young emerging fronds of both A. australasicum and A. nidus are used as a leafy vegetable, from either wild or cultivated plants. [13]
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.
Asplenium nidus is an epiphytic species of fern in the family Aspleniaceae, native to tropical southeastern Asia, eastern Australia, Hawaii, Polynesia, Christmas Island, India, and eastern Africa. It is known by the common names bird's-nest fern or simply nest fern.
Asplenium scolopendrium, commonly known as the hart's-tongue fern, is an evergreen fern in the family Aspleniaceae native to the Northern Hemisphere.
Asplenium bulbiferum, known as mother spleenwort, is a fern species native to New Zealand only. It is also called hen and chicken fern and, in the Māori language, pikopiko, mouku or mauku. Its fronds are eaten as a vegetable.
Asplenium ruprechtii, which goes by the common name Asian Walking Fern, is a rare, hardy, low-lying fern native to East Asia. It is a close relative of Asplenium rhizophyllum which is found in North America and also goes by the common name of walking fern. The species should not be confused with Asplenium sibiricum which is a synonym of Diplazium sibiricum.
Asplenium ceterach is a fern species commonly known as rustyback.
Asplenium septentrionale is a species of fern known by the common names northern spleenwort and forked spleenwort. It is native to Europe, Asia and western North America, where it grows on rocks. Its long, slender leaves give it a distinctive appearance. Three subspecies exist, corresponding to a tetraploid and a diploid cytotype and their triploid hybrid.
Asplenium vespertinum is a species of fern known by the common name western spleenwort. It is native to southern California and Baja California, where it grows in moist, shady, rocky places, such as the shadows beneath cliff overhangs.
Asplenium flaccidum is a species of fern in the family Aspleniaceae. The plant common name is drooping spleenwort or weeping spleenwort, and the species name flaccidum derives from the Latin root meaning drooping. An example occurrence of A. flaccidum is within a Nothofagus-Podocarp forest at Hamilton Ecological District on New Zealand's North Island in association with other fern species understory plants, crown fern, Blechnum discolor being an example.
Asplenium antiquum is a fern of the group known as bird's-nest ferns. In Japanese it is known by ō-tani-watari and tani-watari. It grows on cliffs, in dark forests, and on tree trunks in China, Japan, Korea, and Taiwan. It is classified as an endangered species in both South Korea and Japan.
Asplenium ruta-muraria is a species of fern commonly known as wall-rue. It is a very small epipetric species, growing exclusively on limestone and other calcareous rocks. Its fronds are bluish-green and are heavily sub-divided, becoming up to 12 cm in length.
Asplenium anceps is a diploid fern of family Aspleniaceae and one of the ancestors of the ferns that form the trichomanes complex. It lives exclusively in the three northernmost archipelagoes of the Macaronesian region, that is, is an endemic macaronesian fern. Its fronds are leathery and plastic and rachis is very thick, bright reddish brown and is traversed throughout its length of three wings, two on the upper surface to draw a groove and a third on the lower surface which is characteristic and unique to this species, since all other species of the trichomanes complex without. A typical feature of this fern, which he shares with all its hybrid offspring is the existence of a small atrium on the basis of medium and less pinnae directed toward the apex of the blade with one or two sori on its underside.
Asplenium goudeyi is a fern only found on Lord Howe Island. A common plant growing in a variety of situations. On trees, or rocks, boulders, cliff faces and sometimes in exposed positions. The wavy edged fronds are 50 to 75 cm long, and 12 to 18 cm wide.
Asplenium pteridoides is a species of terrestrial fern in the family Aspleniaceae. It is endemic to Australia's subtropical Lord Howe Island in the Tasman Sea. It is restricted to the cool, moist understorey of the forest on the island's southern mountains.
Asplenium surrogatum is a species of fern in the family Aspleniaceae. It is endemic to Australia's subtropical Lord Howe Island in the Tasman Sea. It grows both terrestrially and as an epiphyte. It occurs in forest at high elevations on the island's mountains.
Asplenium difforme is a plant in the spleenwort group of ferns. Its habitat is cracks in rocky headlands beside the sea. It is found in eastern Australia and Norfolk Island. Its fronds are thick and waxy to protect it from sea spray.
Asplenium fontanum, commonly known as fountain spleenwort or smooth rock spleenwort, is a species of fern in the family Aspleniaceae, native to rocky areas in Western Europe.
Asplenium hookerianum, commonly known as Hooker's spleenwort, rocklax and maidenhair fern, is a small fern native to New Zealand and Australia.
Asplenium gracillimum is a fern species native to Australia and New Zealand, also found in Stewart Island and the Chatham Islands. The specific epithet gracillimum refers to the slender and graceful appearance of this fern.
Asplenium haughtonii, also known as the Barn fern, is a species of fern in the family Aspleniaceae. It is native to Saint Helena.