Plant Comparison

Japanese knotweed vs Turkey tail

A side-by-side comparison of two medicinal plants — every documented constituent, action, use, safety note and cited source, assembled automatically from the Omnia Sana database.

First plant
Second plant
Show:
Plant AJapanese knotweedReynoutria japonicaPolygonaceaeFull monograph →
Plant BTurkey tailTrametes versicolorPolyporaceaeFull monograph →

At a glance

Japanese knotweed and Turkey tail: they share 4 indicated uses (arthritis / joint pain, cancer (anticancer research), inflammation (general), …); 3 pharmacological actions in common.

Japanese knotweedTurkey tail
Constituents43
Pharmacological actions36
Indicated uses58
Safety notes22
Cited sources1417
Indicated uses
Only Japanese knotweed
Cardiovascular / heart health
Shared (4)
Arthritis / joint painCancer (anticancer research)Inflammation (general)Skin irritation
Only Turkey tail
Cold & fluImmune supportInfection (general)Wounds
Pharmacological actions
Only Japanese knotweed
none
Shared (3)
Anti-inflammatoryAnticancer (preclinical)Antioxidant
Only Turkey tail
AntimicrobialAntiviralImmunomodulator / immune support

Evidence face-off — shared uses

ConditionJapanese knotweedTurkey tailVerdict
Arthritis / joint pain2/105/10Stronger for Turkey tail
Cancer (anticancer research)2/109/10Stronger for Turkey tail
Inflammation (general)7/105/10Stronger for Japanese knotweed
Skin irritation1/105/10Stronger for Turkey tail

Evidence scores (1–10) are computed from the tier of each cited source. “Comparable” means the two scores are within one point. Follow a score to its detailed sources.

Key Constituents

Stilbenes (resveratrol, piceid)[1, 6]

Considered the principal bioactive constituents, responsible for much of the antioxidant, anti-inflammatory and cardioprotective activity attributed to this root.

Anthraquinones (emodin, physcion)[1]

Emodin has laxative and anti-inflammatory activity at typical concentrations but can cause gastrointestinal upset at high doses.

Anthraquinones
Polysaccharides[5]

Studied for immunomodulatory and other bioactivities.

Polysaccharides
Phenolic glycosides[8]

Minor phenolic constituents of the rhizome.

GlycosidesPhenolic compounds
Beta-glucan polysaccharides[11, 12]

The principal immunomodulating constituents, forming the basis of PSK/PSP extracts.

Polysaccharides
Polysaccharopeptide (PSK/PSP, protein-bound polysaccharide)[12]

Protein-bound polysaccharide complex studied extensively as an adjunct immunotherapy.

Polysaccharides
Phenolic compounds and triterpenes[13]

Minor antioxidant constituents.

Phenolic compoundsTerpenes / terpenoids

Pharmacological Actions

Anti-inflammatory[1, 2, 3, 5, 6, 9, 11, 12, 13]
Anticancer (preclinical)[1, 3, 6, 7, 11, 12, 13]
Antioxidant[1, 3, 5, 6, 11, 12, 13]
Anti-inflammatory[11, 12, 13]
Anticancer (preclinical)[1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13]
Antimicrobial[11, 12, 13]
Antioxidant[8, 9, 10, 11, 12, 13]
Antiviral[11, 12, 13]
Immunomodulator / immune support[1, 2, 3, 4, 5, 6, 7, 9, 11, 12, 13]

Traditional & Indicated Uses

Arthritis / joint pain[9, 11, 12, 13]Traditional · 2/10

inferred from anti-inflammatory action

Evidence: 2
Label: Arthritis / joint pain
Cancer (anticancer research)[7]Traditional · 2/10

inferred from anticancer action

Evidence: 2
Label: Cancer (anticancer research)
Cardiovascular / heart health[6, 11, 12, 13]Traditional · 1/10
Evidence: 1
Label: Cardiovascular / heart health
Inflammation (general)[2, 11, 12, 13]Good · 7/10

inferred from anti-inflammatory action

Evidence: 7
Label: Inflammation (general)
Skin irritation[11, 12, 13]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Skin irritation
Arthritis / joint pain[11, 12, 13]Moderate · 5/10

inferred from anti-inflammatory action

Evidence: 5
Label: Arthritis / joint pain
Cancer (anticancer research)[1, 2, 3, 4, 6, 12]Strong · 9/10

inferred from anticancer action

Evidence: 9
Label: Cancer (anticancer research)
Cold & flu[11, 12, 13]Moderate · 5/10

inferred from antiviral action

Evidence: 5
Label: Cold & flu
Immune support[11, 12, 13]Moderate · 5/10
Evidence: 5
Label: Immune support
Infection (general)[11, 12, 13]Moderate · 5/10

inferred from antimicrobial action

Evidence: 5
Label: Infection (general)
Inflammation (general)[11, 12, 13]Moderate · 5/10

inferred from anti-inflammatory action

Evidence: 5
Label: Inflammation (general)
Skin irritation[11, 12, 13]Moderate · 5/10

inferred from anti-inflammatory action

Evidence: 5
Label: Skin irritation
Wounds[11, 12, 13]Moderate · 5/10

inferred from antimicrobial action

Evidence: 5
Label: Wounds

Safety, Cautions & Contraindications

Safety note[11, 12, 13]Caution

Japanese knotweed root contains resveratrol and emodin; high doses of emodin may cause GI discomfort and have laxative effects. Not recommended during pregnancy (emodin has potential teratogenic effects in animal studies). May interact with anticoagulants and antiplatelet medications. Quality control of commercial preparations is important as invasive weed extracts vary significantly.

Safety note[11, 12, 13, 14]Info

Duke (2002) rates Japanese knotweed (listed as Hu-Zhang, Fallopia japonica) as +++ and highlights its rich content of resveratrol and emodin. Experimental evidence (score 1) supports COX-2 inhibitory, antioxidant, anti-inflammatory, hepatoprotective, and lipid-lowering activities — largely attributed to resveratrol. Duke notes its use in traditional Chinese medicine for fractures, burns, abscesses, and gynecological conditions. No significant clinical trials were available at time of publication, but resveratrol's biological activity is well-documented in vitro (Duke, 2002).

Safety note[11, 12, 13]Caution

Generally very safe and well tolerated. Rare cases of digestive upset or allergic reaction. No significant known drug interactions at normal doses. The PSK pharmaceutical form is used safely alongside standard cancer treatments. Suitable for most adults.

Safety note[11, 12, 13, 14]Info

Duke (2002) does not include a dedicated entry for Turkey tail mushroom (Trametes versicolor) in the Handbook of Medicinal Herbs, Second Edition.

External Ids

Gbif: 2889173
Wikidata: Q18421053
Gbif: 2548311
Wikidata: Q753833

Botanical Description

Vigorous, invasive rhizomatous perennial (Polygonaceae) with hollow, bamboo-like, jointed stems 1-3 m tall (occasionally taller), speckled reddish-purple. Leaves are broad, heart- to shovel-shaped with a flat base. Abundant sprays of small, creamy-white flowers appear in late summer, followed by small winged fruit.[6]

Height: 1-3 m (occasionally to 4 m+)
Habit: Vigorous, invasive, rhizomatous perennial
Leaves: Broad, heart- to shovel-shaped, flat-based
Flowers: Small, creamy-white, in abundant sprays
Stem: Hollow, bamboo-like, jointed, reddish-purple speckled
Root: Extensive, deep, aggressively spreading rhizome
Fruit: Small winged achenes
Flowering Period: August-October

Bracket fungus (not a true plant) forming thin, tough, fan-shaped, overlapping shelves on dead or decaying hardwood, with a velvety, concentrically zoned upper surface in bands of brown, tan, cream, blue-grey and rust, and a white, minutely pored underside.

Height: Individual brackets 2-8 cm across, forming overlapping clusters
Habit: Bracket (shelf) fungus growing directly from dead wood, in tiered, overlapping clusters
Leaves: Not applicable (fungus); the fruiting body is a thin, tough bracket
Flowers: Not applicable (fungus); reproduces via spores released from pores on the underside
Stem: No true stem; the bracket attaches directly to the wood
Root: Not applicable; mycelium threads through the wood substrate
Fruit: Fan-shaped fruiting body (bracket) with a white, densely pored underside
Flowering Period: Fruiting bodies present year-round, most abundant in autumn

Habitat

Native to East Asia (Japan, China, Korea), now a notorious invasive species across Europe and North America, growing in disturbed ground, riverbanks, roadsides and waste land, spreading aggressively via an extensive rhizome network.[6]

Grows on dead, dying or fallen hardwood logs, stumps and branches in woodlands worldwide, including Europe, Asia and North America.

Harvesting

The rhizome/root, the main medicinal part, is dug in autumn or winter when resveratrol content is highest; young spring shoots (stems) are also edible and used. Strict containment is required when harvesting, given the plant's severe invasiveness.[6]

Parts: Root, Stem
Season: Root in autumn/winter; young stems in spring

Fresh brackets are harvested by cutting from the wood; for medicinal use the tough fruiting body is typically dried and then decocted (simmered) for a long time, or extracted, since the beneficial polysaccharides are not well-extracted by simple infusion.

Parts: Mycelium, Whole Plant
Season: Year-round, most abundant in autumn

Traditional Uses

Known as Hu Zhang in Traditional Chinese Medicine, Japanese knotweed root has a centuries-old use for inflammation, infections, jaundice and menstrual complaints. Modern interest centres on its resveratrol and emodin content, now studied (as Polygonum cuspidatum extract) for antioxidant, anti-inflammatory, cardioprotective and hepatoprotective activity, and more recently for supportive use in acute respiratory infections.[2, 3, 6]

Turkey tail has a long history of use in traditional Chinese medicine (as yun zhi) and is one of the most researched medicinal mushrooms, with standardized polysaccharide-K (PSK) and polysaccharopeptide (PSP) extracts used clinically in Japan and China alongside conventional cancer treatment to support immune function.[11, 12, 13]

Preparations

Decoction[6]

Dried rhizome simmered in water, the classic Traditional Chinese Medicine preparation.

Standardised resveratrol extract (capsule)[1]

The modern commercial supplement form, standardised for resveratrol content.

Long decoction[11]

Dried fruiting body simmered in water for an extended period (often 1-2 hours) to extract the beta-glucan polysaccharides, then strained.

Standardized extract (PSK/PSP)[12]

Standardized polysaccharide-K (PSK) or polysaccharopeptide (PSP) extract, the pharmaceutical-grade forms used in clinical research.

Dosage

Standardised extract[11, 12, 13]

Duke (2002) and general phytotherapy guidance treat this as an experimentally supported herb without a single agreed clinical dose; commercial resveratrol-standardised extracts should be dosed per product labelling. Educational reference only, not a prescription; avoid in pregnancy.

Standardized extract[12]

Clinical research on PSK commonly uses around 3 g daily in divided doses. Educational reference only, not a prescription.

References

REF-0979, REF-0980, REF-0981, REF-0982, REF-0983, REF-0984, REF-0985, REF-0986, REF-0987, REF-0988
REF-1582, REF-1583, REF-1584, REF-1585, REF-1586, REF-1587, REF-1588, REF-1589, REF-1590, REF-1591

Lookalikes Review

Outcome: none-known
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07
Outcome: has-lookalikes
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07

Dangerous Lookalikes

Not documented

Safety note[15, 16, 17]Caution
Dangerous Plant: stereum-hirsutum
Confused Part: The whole fan-shaped bracket (the concentrically zoned shelf growing on dead hardwood), especially the top surface, which looks almost identical from above.
Confusion Context: False turkey tail (Stereum hirsutum, and the near-identical Stereum ostrea) is the commonest fungus mistaken for medicinal turkey tail. Seen from above the two are near-identical: overlapping, fan-shaped, concentrically banded, fuzzy-topped brackets on dead wood. Stereum is NOT poisonous - it is simply inedible (too thin and leathery) and there are no documented poisonings. The problem is that it is a crust fungus lacking the medicinal polysaccharides of true turkey tail, so anyone who brews it gets a worthless tea. This record exists to prevent a wasted, ineffective harvest, not to warn of poisoning.
Distinguishing Features: UNDERSIDE (decisive): true turkey tail has a whitish PORE surface underneath, densely covered with tiny pores/tubes (about 2-5 per mm, visible with a hand lens). False turkey tail (Stereum) has a completely SMOOTH, poreless underside - it is a crust fungus, not a polypore., Underside colour: true turkey tail's pore surface is white to off-white. Stereum's smooth underside is typically tan, yellowish, greyish or pale reddish-brown; a coloured, non-white underside is a red flag., Texture: true turkey tail is thin and flexible; Stereum tends to be tougher, more leathery and often wavier at the margin.
Key Test: Turn the bracket over and look at the underside with a hand lens. Genuine turkey tail shows a white surface densely covered in tiny pores (roughly 2-5 per mm). If the underside is SMOOTH and poreless (and often tan/orange/brown rather than white), it is false turkey tail (Stereum) - discard it. Smooth underside = not turkey tail.
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07

References & Sources

  1. Dong, X., Fu, J., Yin, X., Cao, S. and others (2016) 'Emodin: A Review of its Pharmacology, Toxicity and Pharmacokinetics', Phytotherapy Research, 30(8), pp. 1207-1218. doi:10.1002/ptr.5631 Traditional / reference
    https://doi.org/10.1002/ptr.5631
  2. Wang, S., Yang, Y., Sun, L., Qiao, G. and others (2022) 'Reynoutria japonica Houtt for Acute Respiratory Tract Infections in Adults and Children: A Systematic Review', Frontiers in Pharmacology, 13, pp. 787032. doi:10.3389/fphar.2022.787032 Meta-analysis / review
    https://doi.org/10.3389/fphar.2022.787032
  3. Ke, Y., Zhan, L., Lu, T., Zhou, C. and others (2023) 'Advances for pharmacological activities of Polygonum cuspidatum (Reynoutria japonica) - A review', Pharmaceutical Biology, 61(1), pp. 177-188. doi:10.1080/13880209.2022.2158349 Traditional / reference
    https://doi.org/10.1080/13880209.2022.2158349
  4. Zhang, Q., Zhao, Y., Zhang, M., Zhang, Y. and others (2021) 'Bioactive amides from Reynoutria japonica', Journal of Asian Natural Products Research, 23(3), pp. 228-234. doi:10.1080/10286020.2021.1873298 Preclinical
    https://doi.org/10.1080/10286020.2021.1873298
  5. Lai, Y., Zhou, C., Huang, P., Dong, Z. and others (2024) 'Polygonum cuspidatum polysaccharide: A review of its extraction and purification, structure analysis, and biological activity', Journal of Ethnopharmacology, 331, pp. 118079. doi:10.1016/j.jep.2024.118079 Traditional / reference
    https://doi.org/10.1016/j.jep.2024.118079
  6. Peng, W., Qin, R., Li, X. and Zhou, H (2013) 'Botany, phytochemistry, pharmacology, and potential application of Polygonum cuspidatum Sieb. et Zucc.: a review', Journal of Ethnopharmacology, 148(3), pp. 729-745. doi:10.1016/j.jep.2013.05.007 Traditional / reference
    https://doi.org/10.1016/j.jep.2013.05.007
  7. Wang, X., Liang, L., Yan, J., Li, Z. and others (2023) 'Citri Reticulatae Pericarpium-Reynoutria japonica Houtt. herb pair suppresses breast cancer liver metastasis by targeting ECM1-mediated cholesterol biosynthesis pathway', Phytomedicine, 116, pp. 154896. doi:10.1016/j.phymed.2023.154896 Preclinical
    https://doi.org/10.1016/j.phymed.2023.154896
  8. Jiang, Y., Liu, Y., Zhang, X. and others (2020) 'New phenolic glycosides from Reynoutria japonica', Journal of Asian Natural Products Research, 22(1), pp. 17-23. doi:10.1080/10286020.2019.1646730 Preclinical
    https://doi.org/10.1080/10286020.2019.1646730
  9. Liu, Y., Wang, J., Li, Q. and others (2024) 'The Possibility of Polygonum cuspidatum against Osteoarthritis based on Network Pharmacology', Current Computer-Aided Drug Design, 20(2), pp. 121-133. doi:10.2174/1573409919666230403114131 Preclinical
    https://doi.org/10.2174/1573409919666230403114131
  10. Espinosa-Andrews, H., Morales-Hernandez, N., Garcia-Marquez, E. and others (2025) 'Physicochemical and rheological characteristics of commercial Greek-style yogurt enriched with Polygonum cuspidatum roots or the P. cuspidatum beta-cyclodextrin inclusion complex', Food Research International, 203, pp. 115854. doi:10.1016/j.foodres.2025.115854 Preclinical
    https://doi.org/10.1016/j.foodres.2025.115854
  11. Burns, J., Yokota, T., Ashihara, H., Lean, M.E.J. and Crozier, A (2002) 'Plant foods and herbal sources of resveratrol', 50(11), pp. 3337--3340. doi:10.1021/jf0112973 Traditional / reference
    https://doi.org/10.1021/jf0112973
  12. Royal Botanic Gardens, Kew (n.d.). Available at: https://powo.science.kew.org Traditional / reference
    https://powo.science.kew.org
  13. World Health Organization (2007) 'WHO Monographs on Selected Medicinal Plants'. Traditional / reference
    https://scholar.google.com/scholar?q=WHO%20Monographs%20on%20Selected%20Medicinal%20Plants
  14. Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
    https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition
  1. Pilkington, K., Wieland, L.S., Teng, L., Jin, X.Y. and others (2022) 'Coriolus (Trametes) versicolor mushroom to reduce adverse effects from chemotherapy or radiotherapy in people with colorectal cancer', Cochrane Database of Systematic Reviews, 11(11), pp. CD012053. doi:10.1002/14651858.CD012053.pub2 Meta-analysis / review
    https://doi.org/10.1002/14651858.CD012053.pub2
  2. Habtemariam, S (2020) 'Trametes versicolor (Synn. Coriolus versicolor) Polysaccharides in Cancer Therapy: Targets and Efficacy', Biomedicines, 8(5), pp. 135. doi:10.3390/biomedicines8050135 Meta-analysis / review
    https://doi.org/10.3390/biomedicines8050135
  3. Fritz, H., Kennedy, D.A., Ishii, M., Fergusson, D. and others (2015) 'Polysaccharide K and Coriolus versicolor extracts for lung cancer: a systematic review', Integrative Cancer Therapies, 14(3), pp. 201-211. doi:10.1177/1534735415572883 Meta-analysis / review
    https://doi.org/10.1177/1534735415572883
  4. Tsang, K.W., Lam, C.L., Yan, C., Mak, J.C. and others (2003) 'Coriolus versicolor polysaccharide peptide slows progression of advanced non-small cell lung cancer', Respiratory Medicine, 97(6), pp. 618-624. doi:10.1053/rmed.2003.1490 Randomized trial
    https://doi.org/10.1053/rmed.2003.1490
  5. Ng, T.B (1998) 'A review of research on the protein-bound polysaccharide (polysaccharopeptide, PSP) from the mushroom Coriolus versicolor (Basidiomycetes: Polyporaceae)', General Pharmacology, 30(1), pp. 1-4. doi:10.1016/s0306-3623(97)00076-1 Meta-analysis / review
    https://doi.org/10.1016/s0306-3623(97)00076-1
  6. Kowalczewska, M., Piotrowski, J., Jedrzejewski, T. and Kozak, W (2016) 'Polysaccharide peptides from Coriolus versicolor exert differential immunomodulatory effects on blood lymphocytes and breast cancer cell line MCF-7 in vitro', Immunology Letters, 174, pp. 37-44. doi:10.1016/j.imlet.2016.04.010 Preclinical
    https://doi.org/10.1016/j.imlet.2016.04.010
  7. Jedrzejewski, T., Piotrowski, J., Kowalczewska, M., Wrotek, S. and Kozak, W (2015) 'Polysaccharide peptide from Coriolus versicolor induces interleukin 6-related extension of endotoxin fever in rats', International Journal of Hyperthermia, 31(6), pp. 626-634. doi:10.3109/02656736.2015.1046953 Preclinical
    https://doi.org/10.3109/02656736.2015.1046953
  8. Scarpari, M., Reverberi, M., Parroni, A., Scala, V. and others (2017) 'Tramesan, a novel polysaccharide from Trametes versicolor. Structural characterization and biological effects', PLoS One, 12(8), pp. e0171412. doi:10.1371/journal.pone.0171412 Preclinical
    https://doi.org/10.1371/journal.pone.0171412
  9. Lysakowska, P., Sobota, A. and Wirkijowska, A (2023) 'Medicinal Mushrooms: Their Bioactive Components, Nutritional Value and Application in Functional Food Production - A Review', Molecules, 28(14), pp. 5393. doi:10.3390/molecules28145393 Meta-analysis / review
    https://doi.org/10.3390/molecules28145393
  10. Wang, K.F., Sui, K.Y., Guo, C. and Liu, C.Z (2017) 'Quorum sensing molecule-farnesol increased the production and biological activities of extracellular polysaccharide from Trametes versicolor', International Journal of Biological Macromolecules, 104(Pt A), pp. 377-383. doi:10.1016/j.ijbiomac.2017.06.053 Preclinical
    https://doi.org/10.1016/j.ijbiomac.2017.06.053
  11. Chu, K.K., Ho, S.S. and Chow, A.H (2002) 'Coriolus versicolor: a medicinal mushroom with promising immunotherapeutic values', 42(9), pp. 976--984. doi:10.1177/0091270002042009004 Traditional / reference
    https://doi.org/10.1177/0091270002042009004
  12. Standish, L.J., Wenner, C.A., Sweet, E.S., Bridge, C., Nelson, A., Martzen, M., Novack, J. and Torkelson, C (2008) 'Trametes versicolor mushroom immune therapy in breast cancer', 6(3), pp. 122--128. Traditional / reference
    https://scholar.google.com/scholar?q=Trametes%20versicolor%20mushroom%20immune%20therapy%20in%20breast%20cancer
  13. Wasser, S.P (2011) 'Current findings, future trends, and unsolved problems in studies of medicinal mushrooms', 89(5), pp. 1323--1332. doi:10.1007/s00253-010-3067-4 Randomized trial
    https://doi.org/10.1007/s00253-010-3067-4
  14. Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
    https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition
  15. Macalester College, Katharine Ordway Natural History Study Area 'Turkey Tail Fungus (Trametes versicolor)'. Available at: https://www.macalester.edu/ordway/biodiversity/inventory/turkeytailfungus/ Traditional / reference
    https://www.macalester.edu/ordway/biodiversity/inventory/turkeytailfungus/
  16. Missouri Department of Conservation 'False Turkey Tail (Stereum ostrea)'. Available at: https://mdc.mo.gov/discover-nature/field-guide/false-turkey-tail Traditional / reference
    https://mdc.mo.gov/discover-nature/field-guide/false-turkey-tail
  17. Kuo, Michael 'Stereum ostrea (False Turkey Tail)'. Available at: https://www.mushroomexpert.com/stereum_ostrea.html Traditional / reference
    https://www.mushroomexpert.com/stereum_ostrea.html

Generated automatically from the Omnia Sana plant database and its cited sources. For educational purposes only — not medical advice. Always consult a qualified practitioner before using medicinal plants.