| Green spleenwort | |
|---|---|
| |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | Polypodiophyta |
| Class: | Polypodiopsida |
| Order: | Polypodiales |
| Suborder: | Aspleniineae |
| Family: | Aspleniaceae |
| Genus: | Asplenium |
| Species: | A. viride
|
| Binomial name | |
| Asplenium viride | |
Asplenium viride is a species of fern known as the green spleenwort because of its green stipes and rachides. This feature easily distinguishes it from the very similar-looking maidenhair spleenwort, Asplenium trichomanes.
Green spleenwort was described by Carl Linnaeus in his 1753 Species Plantarum, under the name "Asplenium Trich. ramosum", with a type locality of "in Arvorniæ rupibus" (rocks in Caernarfonshire).[1] Under the rules of the International Code of Botanical Nomenclature, phrase names such as "Asplenium Trichomanes ramosum" are to be treated as orthographic errors – in this case, for "Asplenium ramosum".[2] That name was later rejected in favour of William Hudson's later name Asplenium viride,[3] which had a type locality of "in rupibus humidis in montibus Walliæ et in comitatibus Eboracensi et Westmorlandico" (damp rocks in the mountains of Wales, Yorkshire and Westmorland).[4]
A global phylogeny of Asplenium published in 2020 divided the genus into eleven clades,[5] which were given informal names pending further taxonomic study. A. viride belongs to the "A. viride subclade" of the "A. trichomanes clade".[6] The A. trichomanes clade has a worldwide distribution. Members of the clade grow on rocks and usually have once-pinnate leaf blades with slender, chestnut- to dark-brown stalks. The A. viride subclade, which contains only A. viride and its allopolyploid descendant A. adulterinum, is exceptional in having green stalks.[7]
A. viride is a native species of northern and western North America and northern Europe and Asia. It is a small rock fern, growing on calcareous rock. It is a diploid species, with n = 36, and hybridizes with Asplenium trichomanes to produce Asplenium × adulterinum, found on Vancouver Island, British Columbia.
