Asplenium Platyneuron - Taxonomy

Taxonomy

The basionym for this species is Acrostichum platyneuros, published by Linnaeus in Species Plantarum in 1753. Linnaeus' treatment came from a 1745 dissertation by his student J. B. Heiligtag, which in turn drew on the descriptions by several earlier authorities. The first description listed was that of Gronovius in Flora Virginica, based on a specimen collected by John Clayton. The specific epithet platyneuros ("flat nerves") was drawn from a description by Leonard Plukenet. Unfortunately, only Clayton's specimen, now the lectotype for the species, represents the species now known as Asplenium platyneuron; the specimens upon which the other descriptions, including that of Plukenet which yielded the specific epithet, are based on a mixture of Pleopeltis polypodioides and Polypodium virginianum sensu lato. In 1789, the species was independently described by William Aiton in Hortus Kewensis, and given the name Asplenium ebeneum, referring to the ebony color of its stalk. The species was also independently described by Swartz in 1801, as Asplenium polypodioides, and by Michaux in 1803 as Asplenium trichomanoides; both these names were reduced to synonymy with Asplenium ebeneum by Willdenow.

It was Aiton's epithet, ebeneum, that was used by American botanists throughout most of the 19th century. The transfer of Linnaeus' specific epithet to form the name Asplenium platyneuron was mooted by D. C. Eaton in 1878, who attributed the combination to a pencil notation by William Oakes in the margin of a copy of Flora Virginica. Therefore, the combination has historically been attributed to Oakes or Oakes ex D.C.Eaton. However, in 1981, David B. Lellinger pointed out that Eaton had not, in fact, accepted the combination in 1878, preferring the more accurate epithet ebeneum to the less accurate through senior platyneuron. Eaton's use, therefore, was to be treated as a nomen provisiorum. The first valid publication of the combination, then, was that of Britton, Sterns, and Poggenburg in 1888, which implicitly references Linnaeus's basionym. Despite this, the name Asplenium ebeneum continued to be widely used through 1896, when Lucien Underwood, in Britton & Brown, used the name Asplenium platyneuron with explicit reference to the basionym.

The species has twice been placed in genera segregated from Asplenium: as Chamaefilix platyneuron by Farwell in 1931, and as Tarachia platyneura by Momose in 1960. Neither combination was widely accepted and current authorities do not recognize these segregate genera.