Horsemint is Mentha longifolia
http://ecommons.cornell.edu/handle/1813/1346 Horsemint, Mentha longifolia, has 7 subspecies - 1. Mentha longifolia subsp. longifolia . Europe, northwest Africa. 2. Mentha longifolia subsp. capensis (Thunb.) Briq. Southern Africa. 3. Mentha longifolia subsp. grisella (Briq.) Briq. Southeastern Europe. 4. Mentha longifolia subsp. noeana (Briq.) Briq. Turkey east to Iran. 5. Mentha longifolia subsp. polyadena (Briq.) Briq. Southern Africa. 6. Mentha longifolia subsp. typhoides (Briq.) Harley. Northeast Africa, southwest Asia. 7. Mentha longifolia subsp. wissii (Launert) Codd. Southwestern Africa. The British garden site Shoot provides a few more common names: Wild mint, Kruisement, Horsemint, and Buddleja mint. www.plantzafrica.com It spreads by underground rhizomes, provides lots of bee and pollinator pollen as well as having culinary and medicinal uses. "Found in most parts of the country and easy to harvest, wild mint is a popular traditional medic...