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
Type (biology) species of the section ... After studying the diverse forms, I came to consider them as belonging to the one and the same specific type. In botanical nomenclature, a "type" ("typus", "nomenclatural type"), "is that element to which the name of a taxon is permanently attached." (article 7.1) In botany a type is either a specimen or an illustration. A specimen is a real plant (or one or more parts of a plant or a lot of small plants), dead and kept safe, "curated", in a herbarium (or the equivalent for fungi). Examples of where an illustration may serve as