© 2015 Finnish Zoological and Botanical Publishing Board. Stachys harkerae sp. nova from western Mexico is characterized by its indumentum on stems, leaves and inflorescences composed of tiny glandular-capitate hairs, hirsute stems, and calyces relatively long-toothed surrounding corolla tube, which is rose to pale rose-orangish, exannulate inside and with the tube 6.7-8.2 mm long. Stachys harkerae is most similar to S. bigelovii but differs in having profusely hirsute stems, slightly larger leaves, shorter corolla tubes and a shorter lower corolla lip. It also differs in distribution and habitat; Stachys harkerae is adapted to wetter and warmer conditions below 1450 m a.s.l., whereas S. bigelovii occupies xeric environments, usually above 2200 m a.s.l. An identification key to Stachys in western Mexico is provided.