Mentha aquatica

Mentha aquatica
Plant in flower
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Lamiales
Family:	Lamiaceae
Genus:	Mentha
Species:	M. aquatica
Binomial name
Mentha aquatica L.

Mentha aquatica (Water Mint; syn. Mentha hirsuta Huds.^[1]) is a perennial plant in the genus Mentha native throughout Europe except for the extreme north, and also northwest Africa and southwest Asia.^[1][2]

It is a herbaceous rhizomatous perennial plant growing to 90 centimetres (35 in) tall. The stems are square in cross section, green or purple, and variably hairy to almost hairless. The rhizomes are wide-spreading, fleshy, and bear fibrous roots. The leaves are ovate to ovate-lanceolate, 2 to 6 centimetres (0.79 to 2.4 in) long and 1 to 4 centimetres (0.39 to 1.6 in) broad, green (sometimes purplish), opposite, toothed, and vary from hairy to nearly hairless. The flowers are tiny, densely crowded, purple, tubular, pinkish to lilac in colour; flowering is from mid to late summer. Water Mint is pollinated by insects, and also spreads by underground rhizomes, like other species of mint. All parts of the plant have a distinctly minty smell.^[2][3][4]

As the name suggests, Water Mint occurs in the shallow margins and channels of streams, rivers, pools, dikes, ditches, canals, wet meadows, marshes and fens. If the plant grows in the water itself, it rises above the surface of the water. It generally occurs on mildly acid to calcareous (it is common on soft limestone) mineral or peaty soils.^[2][3] M. aquatica can occur in certain fen-meadow habitats such as the Juncus subnodulosus-Cirsium palustre plant association.^[5]

It hybridises with Mentha spicata (Spearmint) to produce Mentha × piperita (Peppermint), a sterile hybrid; with Mentha suaveolens (Apple Mint) to produce Mentha × suavis; with Mentha arvensis (Corn Mint) to produce Mentha × verticillata; and with both M. arvensis and M. spicata to give the tri-species hybrid Mentha × smithiana.^[2]

Image gallery

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  corolla mauve, leaves opposite ^[6]

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References

1. ^ ^{a b} Euro+Med Plantbase Project: Mentha aquatica
2. ^ ^{a b c d} Flora of NW Europe: Mentha aquatica
3. ^ ^{a b} Blamey, M. & Grey-Wilson, C. (1989). Flora of Britain and Northern Europe. ISBN 0-340-40170-2
4. ^ Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan ISBN 0-333-47494-5.
5. ^ C. Michael Hogan. 2009. Marsh Thistle: Cirsium palustre, GlobalTwitcher.com, ed. N. Strömberg
6. ^ Rose, Francis (1981). The Wild Flower Key. Frederick Warne & Co. pp. 310. ISBN 0-7232-2419-6.