Omnia SanaEquisetum sylvaticum
Common names in 23 European languages →
The complete database record: 4 documented constituents, 1 pharmacological action, with 9 cited sources.
Botanical Description
Perennial, spore-bearing plant distinguished within the horsetail genus by its finely and repeatedly branched sterile stems, in which each primary whorled branch itself bears further fine side-branches, giving the plant an especially soft, feathery, almost fern-like appearance. It shares the deep black jointed rhizome typical of the genus.
Height: 20-50 cm
Habit: Perennial, spore-bearing herb with finely, repeatedly branched, feathery sterile stems
Leaves: Reduced to small, fused, toothed sheaths at each stem node
Flowers: None; reproduces by spores borne in a cone on separate fertile stems in spring
Stem: Slender, hollow, jointed, with repeatedly branched, feathery whorled branches
Root: Deep, black, jointed rhizome
Fruit: Spores released from the fertile cone, not a true fruit
Flowering Period: Not applicable (spore-bearing); fertile stems appear in spring
Habitat & Distribution
Grows in damp woodland, woodland margins and shaded, boggy ground, typically in cooler northern and upland regions; found across Europe, Asia and North America.
Harvesting
The aerial (sterile) stems are cut in summer and dried; because this species is easily confused with other horsetails, including the more toxic marsh horsetail, careful identification is essential before wild-harvesting.
Parts: Aerial parts, Stem
Season: Summer
Key Constituents
Pharmacological Actions
Traditional Use & History
Wood horsetail shares the broader horsetail genus's traditional folk reputation as a diuretic, astringent and wound-healing herb, though the species itself is very little studied and has no dedicated clinical evidence base of its own.
Safety, Cautions & Contraindications
Safety noteCaution
Wood horsetail (Equisetum sylvaticum) shares the horsetail genus's traditional reputation as a diuretic, astringent and wound-healing herb, but the species itself is very little studied and no clinical data exist. As with other horsetails, prolonged use is cautioned because the genus contains the enzyme thiaminase, which can degrade vitamin B1; thiaminase-inactivated preparations are preferred. Not evaluated for safety in pregnancy or lactation.
Dangerous Lookalikes
Confused Part: Sterile green stems gathered and dried for horsetail tea; toxic marsh horsetail looks very similar and grows in the same damp ground.
Confusion Context: Wood horsetail (Equisetum sylvaticum) is gathered for horsetail tea, but horsetails are notoriously hard to tell apart, and marsh horsetail (Equisetum palustre) - one of the most poisonous plants of wet grasslands - grows in the same damp habitat and looks very similar. Marsh horsetail contains the alkaloids palustrine and palustridiene plus high thiaminase (which destroys vitamin B1); it is a well-known livestock poison, and peer-reviewed work stresses that medicinal horsetail must be properly authenticated and differentiated from the more toxic marsh horsetail, which can adulterate herbal material. Because the species are so alike, unverified wild horsetail is a real hazard.
Distinguishing Features: Branch teeth: marsh horsetail (the toxic one) has 5-6 teeth on each branch sheath that lie flat (appressed) against the branch. Broad, spreading teeth in threes or fours indicate a non-toxic horsetail rather than marsh horsetail., Branches solid vs hollow: marsh horsetail has hollow branches, whereas field horsetail's branches are solid. A hollow first branch segment is a warning sign., First branch segment vs sheath: on marsh horsetail the lowest segment of each side branch is short - shorter than or about equal to the stem sheath it emerges from. A first branch segment clearly longer than the sheath indicates it is NOT marsh horsetail. Marsh horsetail also favours wet, marshy ground and fens.
Key Test: Because horsetails are so alike and marsh horsetail is poisonous, only use wild horsetail if you can positively exclude marsh horsetail (Equisetum palustre): confirm branch sheaths have 3-4 spreading teeth (not 5-6 flat-lying ones), solid (not hollow) branches, and a first branch segment longer than the stem sheath. If you cannot confirm all of these - or the plant grows in wet, marshy ground - do not use it.
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07
Harvest Readiness
[6]
Part: stem
Signals: Cut the green, fully branched sterile stems once the whorls of slender branches have expanded - that is, after the cone-bearing stems have shed their spores and themselves greened up and branched.
Basis: traditional
Source Quote: both types produced at the same time, but those bearing cones remaining non-green and unbranched until after spore dispersal, and only later becoming green and branching so as to resemble the sterile stems vegetatively
Species Confirmed: 1
Notes: Horsetails of Britain and Ireland (DELTA/Intkey) species account for Equisetum sylvaticum L. (REF-3375) - a species-specific flora, so no congener timing is inherited from Equisetum arvense. PFAF had given only 'The barren stems are used, they are most active when fresh' (a freshness note, not a stage) plus spore dates. Single lineage -> provisional. SAFETY: marsh horsetail (Equisetum palustre) is a toxic lookalike - see Dangerous Lookalikes.
External Identifiers
References & Sources
- Wang, Z., Tian, Y., Sugimoto, S., Yamano, Y., Kawakami, S., Otsuka, H. and Matsunami, K (2022) 'Four new glucosides from the aerial parts of Equisetum sylvaticum', Journal of Natural Medicines, 76(4), pp. 832-841. doi:10.1007/s11418-022-01643-0 Preclinical
https://doi.org/10.1007/s11418-022-01643-0 - Batir-Marin, D., Boev, M., Cioanca, O., Mircea, C., Burlec, A.F., Beppe, G.J., Spac, A., Corciova, A., Hritcu, L. and Hancianu, M (2021) 'Neuroprotective and antioxidant enhancing properties of selective Equisetum extracts', Molecules, 26(9), pp. 2565. doi:10.3390/molecules26092565 Preclinical
https://doi.org/10.3390/molecules26092565 - Batir-Marin, D., Mircea, C., Boev, M., Burlec, A.F., Corciova, A., Fifere, A., Iacobescu, A., Cioanca, O., Verestiuc, L. and Hancianu, M (2021) 'In vitro antioxidant, antitumor and photocatalytic activities of silver nanoparticles synthesized using Equisetum species: a green approach', Molecules, 26(23), pp. 7325. doi:10.3390/molecules26237325 Preclinical
https://doi.org/10.3390/molecules26237325 - Patova, O.A., Smirnov, V.V., Golovchenko, V.V., Vityazev, F.V., Shashkov, A.S. and Popov, S.V (2019) 'Structural, rheological and antioxidant properties of pectins from Equisetum arvense L. and Equisetum sylvaticum L', Carbohydrate Polymers, 209, pp. 239-249. doi:10.1016/j.carbpol.2018.12.098 Preclinical
https://doi.org/10.1016/j.carbpol.2018.12.098 - Fry, S.C., Nesselrode, B.H.W.A., Miller, J.G. and Mewburn, B.R (2008) 'Mixed-linkage (1->3,1->4)-beta-D-glucan is a major hemicellulose of Equisetum (horsetail) cell walls', New Phytologist, 179(1), pp. 104-115. doi:10.1111/j.1469-8137.2008.02435.x Preclinical
https://doi.org/10.1111/j.1469-8137.2008.02435.x - Dallwitz, M. J. and Paine, T. A. and Zurcher, E. J 'Horsetails of Britain and Ireland - Equisetum sylvaticum L'. Available at: https://www.delta-intkey.com/britht/www/sylvatic.htm Traditional / reference
https://www.delta-intkey.com/britht/www/sylvatic.htm - NatureSpot 'Marsh Horsetail - Equisetum palustre'. Available at: https://www.naturespot.org/species/marsh-horsetail Traditional / reference
https://www.naturespot.org/species/marsh-horsetail - Muller, J. and Puttich, P.M. and Beuerle, T (2020) 'Variation of the Main Alkaloid Content in Equisetum palustre L. in the Light of Its Ontogeny', Toxins, 12(11), pp. 710. doi:10.3390/toxins12110710 Preclinical
https://doi.org/10.3390/toxins12110710 - Ibi, A. and Du, M. and Beuerle, T. and Melchert, D. and Solnier, J. and Chang, C (2022) 'A Multi-Pronged Technique for Identifying Equisetum palustre and Equisetum arvense - Combining HPTLC, HPLC-ESI-MS/MS and Optimized DNA Barcoding Techniques', Plants, 11(19), pp. 2562. doi:10.3390/plants11192562 Preclinical
https://doi.org/10.3390/plants11192562
Selected studies & references
PreclinicalIn vitro antioxidant, antitumor and photocatalytic activities of silver nanoparticles synthesized using Equisetum species: a green approach source↗ (2021)
PreclinicalNeuroprotective and antioxidant enhancing properties of selective Equisetum extracts source↗ (2021)
PreclinicalStructural, rheological and antioxidant properties of pectins from Equisetum arvense L. and Equisetum sylvaticum L. source↗ (2019)
PreclinicalMixed-linkage (1->3,1->4)-beta-D-glucan is a major hemicellulose of Equisetum (horsetail) cell walls source↗ (2008)
All 5 studies in the Knowledge Finder →
Educational use only. This profile summarises traditional and scientific sources for reference. It is not medical advice and not a substitute for a qualified practitioner. Some plants carry safety cautions and drug interactions - always check before use.
This profile is assembled automatically from the Omnia Sana plant database, which we curate by hand. How this site is built.
This profile is assembled automatically from the Omnia Sana plant database, which we curate by hand. How this site is built.