Mentha dahurica Fisch. ex Benth.

Plants rhizomatous, perennial. Stems erect, 30-60 cm, rarely branched, base leafless, retrorse puberulent, sometimes purplish. Petiole 7-10 mm; leaf blade ovate to oblong, ca. 3 × 1.3 cm, glabrous or sparsely puberulent, abaxially glandular on veins, base broadly cuneate to rounded, margin shallow crenate-serrate to subentire, apex acute to obtuse. Verticillasters 5-13-flowered, generally 2, in terminal capitate inflorescences longer than floral leaves; peduncle 2-10 mm, puberulent; bracteoles linear, curved upward. Pedicel 1-3 mm. Calyx tubular-campanulate, ca. 2.5 mm, veins conspicuous, puberulent; teeth broadly triangular, ca. 0.5 mm, apex acute; fruiting calyx broadly campanulate. Corolla reddish or rose purplish, ca. 5 mm, glabrous, throat puberulent, gradually dilated from base; lobes circular, ca. 1 mm, obtuse, upper lobe conspicuously 2-lobulate. Anterior stamens equal to slightly longer than corolla. Ovary brown, glabrous. Fl. Jul-Aug.

Heilongjiang, Jilin, Nei Mongol [Japan, Russia].

Meadows; ca. 600 m.

Mentha dahurica, or Dahurian thyme, is a mint species within the genus Mentha, native to Siberia, the Russian Far East, Japan, and northeastern China.

The epithet honors the Daur people of Inner Mongolia.