[4] The classification of Perilla is confused, partly because botanists struggled with distinguishing the two distinct cultigens as different species or variations.

[6] An early example of dividing the two cultigens into different species is found in Matsumura's 1884 nomenclature book, where the synonym P. arguta Benth.

Recent genetic research confirms that the cultigens are of a common gene pool, corroborating the taxonomists' claim for consolidating the two crops into one species.

crispa had been dubbed P. nankinensis,[5] and this label was used throughout the 19th century in the West following the introduction of the species for ornamental planting.

crispa fragrance may turn out to be present or absent in the individual or population, and this is not differentiable from outward appearance alone.

Three wild species that are endemic to Japan are recognized as genetically distinct from the cultivated P. frutescens var.