Mints are aromatic, rhizome-bearing perennial herbs with all leaves growing in opposite pairs on the stem. The flowers are arranged in whorls supported by leaves or more or less reduced bracts, the whorls being crowded or not apparent, often forming spikelike flower clusters. The calyx is 10-nerved, regular or slightly 2-lipped, with the 5 teeth equal or unequal in length. The corolla has a short tube and nearly regularly 4-lobed limb, with the upper lobe formed by the fusion of the two lobes of the upper lip, and tending to be broader than the other lobes, and often shallowly notched at the tip. The 4 stamens are equal in length, usually protruding outside the other parts. The pollen sacs are parallel. The genus represents about 15 original species worldwide, one circumboreal, the rest equally divided between Eurasia, America and Australia. The name comes from the Latin menta, Greek minthe, mint, perhaps eventually from the Greek nymph Minthe.
Guide to Identify Presented Species of Genus Mentha
FLOWERS CLUSTERED IN LEAF AXILS
M. arvensis Wild Mint Aromatic, glandular-dotted plant, 20-80 cm tall. Moist to wet sites.
Flowers pinkish, 4-7 mm long, 4-lobed, in dense clusters from upper leaf axils.
Leaves opposite, 2-8 cm long, lance-shaped, sharp-toothed, mostly stalkless.
FLOWERS IN DENSE TERMINAL CLUSTERS
M. spicata Spear Mint Stems single, erect, 30-100 cm tall. Ditches and streambanks.
Flowers whitish, 2-4 mm long, tubular, 4-lobed, clustered in dense, tall spikes.
Leaves opposite, broadly lance-shaped, sharp-toothed, pointed, 2-7 cm long.