Herb: Swamp Horsetail

Latin name: Equisetum fluviatile

Synonyms: Equisetum heliocharis, Equisetum limosum

Family: Equisetaceae (Horsetail Family)

Medicinal use of Swamp Horsetail:

Horsetails have an unusual chemistry compared to most other plants. They are rich in silica, contain several alkaloids (including nicotine) and various minerals. The plant is styptic. The barren stems are used, they are most active when fresh but can also be dried and sometimes the ashes of the plant are used. A decoction applied externally will stop the bleeding of wounds and promote healing.

Description of the plant:


120 cm
(4 feet)

Habitat of the herb:

Shallow water in lakes, ponds and ditches.

Edible parts of Swamp Horsetail:

Strobil (the fertile shoots in spring) - cooked. Used as an asparagus substitute, though it is neither palatable nor nutritious. Caution is advised, see the notes above on toxicity. Roots - cooked. The roots contain a nutritious starch. Caution is advised, see the notes above on toxicity.

Propagation of the herb:

Spores - best collected as soon as they are ripe in the spring and surface-sown immediately on a sterile compost. Keep moist and pot up as soon as the plants are large enough to handle. Very difficult. Division. The plants usually spread very freely when well sited and should not really need any assistance.

Cultivation of Swamp Horsetail:

Shallow water in lakes, ponds and ditches.

Known hazards of Equisetum fluviatile:

Large quantities of the plant can be toxic. This is because it contains the enzyme thiaminase, a substance that can rob the body of the vitamin B complex. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. The enzyme is destroyed by heat or thorough drying, so cooking the plant will remove the thiaminase. The plant also contains equisetic acid - see the notes on medicinal uses for more information.

Plant information taken from the Plants For A Future.