Domenic Cirillo first described
Lamium bifidum in his
Plantarum Rariorum Regni Neapolitani, published in 1788.
John Isaac Briquet's 1897 taxonomy placed the species within the subsection
Amplexicaulia, within the larger section
Pollichia.
Jacob Mennema's 1989 revision of the genus narrowed its close relations, placing it instead within the Subgenus Lamium, in a smaller Section Lamium on the basis of morphological similarities, namely a straight
corolla tube and presence of
bracteoles. This section consists of
L. bifidum as well as
Lamium purpureum and
Lamium confertum. 21st century
phylogenetic studies brought this change into question however, finding a closer genetic relationship between
L. bifidum and
Lamium amplexicaule var.
amplexicaule and
Lamium incisum. A 2016 study of
pollen structuring provided further evidence for this closer relation to the species of section
Amplexicaule rather than section
Lamium. Authors have identified as many as four subspecies: • subsp.
bifidum • subsp.
albimontanum Rech. f. - endemic to Crete • subsp.
balcanicum Velen. endemic to the Balkan Peninsula & Romania, specifically the west Moesian-south Dacian area • subsp.
gevorense Gómez Hern. - endemic to Spain - identified in 1977, but proposed in 2005 to be raised as a separate species,
Lamium gevorense The
albimontanum and
balcanicum subspecies are distinguished from the type species by their pink or purple flowers.
Lamium bifidum var.
clandestinum was previously raised to the separate species of
Lamium cryptanthum, but this is now merely regarded as a synonym. ==Distribution==