Mentha canadensis L.

Source of mint oil. Used in cigarettes, pharmaceuticals, and oral preparations.

Plants rhizomatous, perennial. Stems erect, 50-100 cm, striate, densely retrorse pubescent along angles, little branched. Petiole 0.5-1.5 cm; leaf blade elliptic-lanceolate, (2.5-)4-9 × 1-3.5 cm, glandular, ciliate, puberulent on veins, base attenuate, margin shallow serrate, apex acute. Verticillasters axillary, many flowered, globose, to 1.5 cm in diam., short pedunculate; floral leaves subsessile, sublanceolate; bracteoles linear to linear-lanceolate, 3-4 mm, ciliate. Pedicel ca. 2 mm, glabrous. Calyx campanulate, ca. 1.5 mm, densely pilose, yellow glandular, mouth and teeth pilose inside; teeth narrowly triangular, ca. 1.5 mm, apex acute. Corolla purplish or purplish red, ca. 4 mm, pilose; lobes ovate-oblong, upper emarginate. Anterior stamens slightly longer, ca. 5 mm. Nutlets yellow-brown, oblong, glabrous, ribbed. Fl. Jul-Aug, fr. Sep.

Plants rhizomatous, perennial. Stems erect, 30-60 cm, puberulent, much branched. Petiole 2-10 mm; leaf blade ovate-lanceolate to oblong, 3-5(-7) × 0.8-3 cm, puberulent, base cuneate to rounded, margin remotely coarse dentate-serrate above base, apex acute. Verticillasters axillary, globose, ca. 1.8 cm in diam.; peduncle 0-3 mm. Pedicel slender, 2.5 mm. Calyx tubular-campanulate, ca. 2.5 mm, puberulent, glandular, obscurely 10-veined; teeth narrowly triangular-subulate, apex acuminate, ca. 1 mm. Corolla purplish or white, ca. 4 mm, puberulent; upper lobe largest, 2-lobulate; other lobes subequal, oblong, obtuse. Stamens ca. 5 mm. Nutlets yellow-brown, small pitted. Fl. Jul-Sep, fr. Oct.

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

In all provinces [Cambodia, Japan, Korea, Laos, Malaysia, Myanmar, Russia, Thailand, Vietnam; North America]

Wet grasslands near rivers, lakes; 200-1100 m.

Wet areas; 0-3500 m.

Mentha arvensis Linnaeus subsp. haplocalyx Briquet var. sachalinensis Briquet ex Miyabe & Miyake, Fl. Saghalin 361. 1916; M. arvensis var. piperascens Holmes; M. sachalinensis (Briquet) Kudo var. arguta Kitagawa.

Mentha arvensis Linnaeus var. canadensis (Linnaeus) Maximowicz; M. arvensis f. chinensis Debeaux; M. arvensis subsp. haplocalyx (Briquet) Briquet; M. arvensis var. haplocalyx (Briquet) Briquet; M. haplocalyx Briquet; M. haplocalyx Briquet f. alba X. L. Liu & X. H. Guo; M. pedunculata Hu & Tsai.