Asplenium platyneuron plant. Similar buds have also been reported from the single-sorus spleenwort, "Asplenium monanthes". The species most similar to "Asplenium platyneuron" is the black-stemmed spleenwort, "A. resiliens". However, this stipe of this species is darker, and the pinnae are opposite, rather than alternate, along the rachis. Neither black-stemmed spleenwort nor the other pinnate American spleenworts have dimorphic fertile and sterile fronds. It might be confused with a young Christmas fern, "Polystichum acrostichoides", but that species is generally much larger and has a green, scaly stipe and rachis. It is very similar to Boydston's spleenwort, "Asplenium × boydstoniae", a backcross with Tutwiler's
Asplenium viride Asplenium viride Asplenium viride is known as the green spleenwort because of its green stipes and rachides. This feature easily distinguishes this species 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 "'" (rocks in Caernarfonshire). 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"". That name was later rejected in favour of William Hudson's later