| Horsetail or Common Mare's Tail | ||||||||||||||
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| Scientific classification | ||||||||||||||
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| Binomial name | ||||||||||||||
| Hippuris vulgaris | ||||||||||||||
The Horsetail or Common Mare's Tail, Hippuris vulgaris, is a common water plant of Eurasia and North America.
The horsetail is a creeping, perennial herb, found in shallow waters and mud flats. It roots under water, but most of its leaves are above water. Its leaves are in whorls of 6-12; those above water are 0.5 to 2.5 cm long and up to 3mm wide, whereas those under water are thinner and limper, and longer than those above water, especially in deeper streems. The stems are solid and unbranched but often curve, and can be up to 60cm long. In shallow water they project 20-30cm out of the water. It grows from stout rhizomes. The flowers are inconspicuous, and not all plants produce them.
Its distribution is circumboreal; in the United States it is found mainly in the north-east but extends southwards to New Mexico and Arizona. It prefers non-acidic waters.
In herbal medicine Horsetail has a number of uses, chiefly to do with healing wounds, e.g. stopping internal and external bleeding, curing stomach ulcers, and soothing inflammation of the skin. It has been said to absorb methane in large quantities and so to improve the air quality in the marshes where it is often found. It can however be a troublesome weed, obstructing the flow of water in rivers and ditches.