12. Mentha pulegium Linnaeus, Sp. Pl. 2: 577. 1753.
唇萼薄荷 chun e bo he
Pulegium vulgare Miller.
Herbs. Stolons with scalelike leaves. Stems ascending, rarely erect or trailing, 15-30(-50) cm, hirtellous, striate, tinged red-purple, much branched, internodes generally longer than leaves. Leaf blade ovate-orbicular to ovate, 0.8-1.3 cm × 5-7 mm, herbaceous, puberulent, base rounded, margin entire or sometimes remotely crenate, apex obtuse. Verticillasters 10-30-flowered, globose, 1-1.5 cm in diam., few, widely spaced; floral leaves sessile, recurved, shorter than verticillasters. Pedicel 2-3 mm. Calyx tubular, 2-lipped, 2.5-3 mm, hirtellous, glandular, throat bearded, ± conspicuously 10-veined, tube ca. 1.5 mm; upper lip 3-toothed, teeth lanceolate-triangular, ca. 1 mm; lower lip 2-toothed, teeth subulate, ca. 1.5 mm. Corolla rose, purple or rarely white, ca. 4.5 mm, puberulent; tube ca. 3 mm, abruptly saccate at apex; lobes oblong, ca. 1.5 mm, entire, upper lanceolate. Ovary glabrous. Fl. Sep.
Beijing Shi, Nanjing Shi, and other cities [Russia, Tajikistan, Turkmenistan; SW Asia, Europe]
Cultivated in China. Source of oil of pennyroyal. Employed in the manufacture of soaps and synthetic menthol. Used medicinally for flatulent colic, stomach ailments, and as a diaphoretic.