Mentha x verticillata
- Family: Mint Family – Lamiaceae (Labiatae)
- Growing form: Perennial herb.
- Height: 20–70 cm (8–28 in.). Stem branched, varyingly hairy, often reddish.
- Flower: Usually only imperfect pistillate flowers. Corolla slightly zygomorphic, light reddish, approx. 4 mm (0.16 in.) long, 4-lobed. Uppermost lobe broader than the rest, with notched tip. Calyx narrowly campanulate, 5-lobed, grooved, clearly 10-veined, scantly haired. Lobes triangular. Stamens 4, almost of even length, level with corolla lobes. Gynoecium composed of 2 fused carpels. Flowers in long-stemmed, whorled axillary groups, small leaf rosette in crown.
- Leaves: Opposite, stalked. Leaf blade quite broad, elliptic, often blunt, with serrated margin.
- Fruit: Does not develop.
- Habitat: Shores, stream banks, ditches and damp meadows.
- Flowering time: July–August.
Whorled mint is a sterile hybrid between water mint (M. aquatica) and corn mint (M. arvensis), but it spreads efficiently through underground runners along the banks of waterways. It has spread outside water mint’s current habitat, which is more restricted to the Åland Islands and is more common. A long, narrow, sharp-toothed, very clear-veined calyx is typical of watermint, while corn mint is branched and has longer gaps in the inflorescence. The hairiness varies according to the parent plants: both of water mint’s subspecies – ssp. aquatica and ssp. litoralis – have independently crossed with corn mint to produce whorled mint. The commonality of whorled mint is partly due to the fact that it is cultivated in gardens. The plants are used to produce a pleasing fragrance indoors rather than culinarily or medicinally. It was used with e.g. its relatives sage, lemon balm, lavender, thyme and southernwood from the daisy family in fragrant church bouquets which kept the congregation awake in the old days during long sermons and smothered unpleasant smells. Ornamental, fragrant and often still used in the kitchen, mints are well suited to the modern garden. And much to the delight of enthusiasts, they are highly attractive to bees and butterflies.