The closest living relatives of "Agastache" are believed to be two very different lineages: One is a group of mostly Asian and usually strongly aromatic and rather robust plants, which contains the typical dragonheads ("Dracocephalum"), true hyssops ("Hyssopus"), West Asian dragonheads ("Lallemantia"), and Japanese catnip ("Schizonepeta"). By contrast, the other lineage unites the largely scentless and low-growing genera "Glechoma" and "Meehania" which occur widely across the Holarctic. These three lineages form a tight-knit radiation; as of 2016, it is not resolved with certainty which of the other two lineages is the sister taxon of "Agastache", but most data place the aromatic group slightly closer. The genus "Agastache" seems to have originated as a North American/trans-Beringian offshoot of its radiation about 25 million years ago, in the Late Oligocene.