Agastache derives from the Ancient Greek words ἄγαν (ágan) "very much" and στάχυς (stákhus) "ear of grain",[5] describing the flower spikes.

[6] The genus was established in 1762 by Jan Frederik Gronovius in the second edition of his controversial Flora Virginica, based on the specimens and notes of John Clayton.

The Nepetinae are robustly supported by cladistic analyses of morphological and DNA sequence data, and were recognized as early as the mid-late 19th century.

[11][12] The sister group of this clade is the core of the Nepetinae, the more or less robust and typically aromatic catmints (Nepeta) and their close relatives[13] which occur mainly in and around western Asia.

The plesiomorphic appearance of Agastache is underscored by the fact that some of its species were formerly placed in Lophanthus and even Cedronella; essentially, the genus as recognized today was distributed piecemeal across the entire Nepetinae.

In general, the evolutionary pattern of the subtribe is a mostly eastward expansion from an origin in the southern or the eastern Mediterranean region, which spread across much of the Old World and with three genera reached North America.

Its members have a more well-developed upper corolla lip, under which the stamina run parallel to each other without crossing, and are entirely hidden from view or only protrude with the anthers and stalk tips.