Wood Horsetail, Woodland horsetail

Equisetum sylvaticum

Physical Characteristics

Equisetum sylvaticum is a PERENNIAL growing to 0.6 m (2ft). See above for USDA hardiness. It is hardy to UK zone 2. The seeds ripen from April to May. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland). It prefers moist soil.

Distribution

Temperate regions of Europe, including Britain, N. America and Asia.

Habitats

Woodland Garden Dappled Shade; Shady Edge;

Edible Uses

Edible Parts: Root Shoots Stem Edible Uses: Strobil (the fertile shoots in spring) - cooked[177]. An asparagus substitute, though it is neither very palatable nor very nutritious. Caution is advised, see the notes above on toxicity. Roots - cooked. A source of starch[177]. Caution is advised, see the notes above on toxicity.

Medicinal Uses

Astringent Diuretic Haemostatic Kidney Poultice Styptic 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 astringent, diuretic and styptic. The barren stems are used, they are most active when fresh but can also be dried and sometimes the ashes of the pant are used. The plant is a useful diuretic when taken internally and is used in the treatment of kidney and bladder problems, internal bleeding. A decoction applied externally will stop the bleeding of wounds and promote healing.

Known Hazards

Large quantities of the plant can be toxic. This is because it contains the enzyme thiaminase[172], a substance that can rob the body of the vitamin B complex[65]. 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[172]. The plant also contains equisetic acid - see the notes on medicinal uses for more information[213].