7. Mentha X piperita Linnaeus, Sp. Pl. 2: 576. 1753.
辣薄荷 la bo he
Stems erect-ascending, 30-100 cm tall, branched, purple-red, glabrous or angles sparsely minutely hispid. Petiole 1-2 mm, purple; leaf blade lanceolate to ovate-lanceolate, 2.5-3 × 0.8-2 cm, glabrous or abaxially minutely hispid on veins, densely glandular, base rounded to shallow cordate, margin unequally acute serrate, apex acute. Verticillasters in cylindric terminal spikes, interrupted at base; bracts linear-lanceolate, slightly longer than calyx, ciliate. Pedicel ca. 1 mm. Calyx tubular, tinged purple, puberulent or subglabrous, glandular outside; teeth 5, linear-subulate, ca. 1 mm, ciliate. Corolla white, tinged red on lobes, ca. 4 mm, tube nearly as long as calyx; lobes subequal, upper emarginate. Nutlets brown, obovoid, ca. 0.7 mm, apex glandular. Fl. Jul, fr. Aug.
Beijing Shi, Nanjing Shi, and other cities [India, Japan, Kyrgyzstan, Russia, Tukmenistan; SW Asia, Europe, North America]
Cultivated in China. Source of peppermint oil, an essential oil used for flavoring confectionary, candies, liqueur, and chewing gum. The dried plant is used medicinally as a carminative, nervine, and stimulant, while menthol is used in nasal sprays.
A hybrid: Mentha aquatica Linnaeus X M. spicata Linnaeus.