"Agastache" is divided into two sections, sect. "Agastache" and sect. "Brittonastrum". The former occurs in and around western to central North America, extending across the Bering Strait into East Asia. It is characterized by the upper lip of the corolla being small, causing the stalks of the stamina to protrude widely. Furthermore, two of the four stamina have curving stalks, which cross those of the other pair. Section "Brittonastrum" is found in and around southwestern North America, with the highest diversity in the uplands of northern Mexico. 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.