The Chadwicks, in their first edition of their book on The Classic Cattleyas, have a fascinating account of the history of the species (pp.153-157, 2006). It was in the 19th century described by preeminent botanists as Cattleya (e.g. Lemaire, Beer) as well as Laelia (Lindley). The Chadwicks rather wittily likened the chaotic status of the species' classification to "... a game of botanical checkers" (p. 156).
The Chadwicks chastisize Lindley's taxonomic position to place purpurata within the genus Laelia (later on to be codified by Bentham and Hooker, supported by Veitch) for only taking into account the number of pollinias, while neglecting other important features, such as geographical distribution ( Mexico vs. the South of Brazil) and other morphological features: "... it's pseudobulbs and flower spikes [are] like the typical South American large-flowered Cattleya species, not the Mexican laelias" (p. 155). That placing purpurata within Cattleya now furthermore is supported by emerging genetic evidence, no matter how misty, is to be considered, but only another piece of the puzzle.
The Chadwicks ascribe the circumstance that no one during the entire 20th century did challenge the classification, that kept the species purpurata out of the genus Cattleya, "despite its atrocious logic" to the fact, that "... even a child of three or four could tell the difference between four and eight".
In their words, "It... took modern science in a new millennium to separate Brazil from Mexico" (p. 156) - or, maybe, phrased in another way, that it is with the distinction behind the classification within laelia as it is with the Emperor's new clothes in the eponymous tale by my illustrious compatriot, where the Emperor was, indeed, wearing nothing, but the costume, God had made for Adam!