Bidens pilosa (Asteraceae) Blackjack, Spanish Needle, Hairy Beggarticks

Bidens pilosa, commonly known as blackjack, Spanish needle, or hairy beggarticks, is an annual herbaceous plant native to the Americas, now widely distributed across tropical and subtropical regions worldwide. It is a member of the Asteraceae family, the largest family of flowering plants, and is often considered a weed due to its invasive nature and ability to thrive in disturbed soils. Despite this reputation, it has been a cornerstone of traditional medicine for centuries, used across Latin America, Africa, Asia, and Oceania to treat a wide range of ailments. It is known as a remedy for over 40 disorders, including inflammation, diabetes, wounds, and infectious diseases, making it a plant of immense ethnobotanical significance . Today, modern science is validating these traditional uses, revealing a plant with a complex and potent pharmacological profile driven by a diverse array of bioactive compounds.

1. Taxonomic Insights

Species: Bidens pilosa L.

Family: Asteraceae

The Asteraceae family, also known as the daisy or sunflower family, is the largest family of flowering plants, comprising over 32,000 known species. The family is characterised by its inflorescence, which is a composite head (capitulum) of many small florets, often surrounded by bracts. The genus Bidens includes approximately 230-240 species of flowering plants distributed globally, many of which are known for their barbed seeds (achenes) that easily attach to clothing and animal fur, facilitating their spread .

Taxonomic Note: The species was first described by Carl Linnaeus in 1753. The genus name Bidens is derived from the Latin bis (two) and dens (tooth), referring to the two barbed awns found on the seeds of many species. The specific epithet pilosa is Latin for "hairy," a reference to the fine hairs covering the plant's stems and leaves. This annual herb can grow up to 1.8-2 metres in height and is easily recognised by its branched, ridged stems, its opposite, pinnate leaves with serrated, ovate leaflets, its capitulum inflorescence of white ray petals and yellow centres, and its characteristic brown to black barbed seeds .

Related Herbs from the Same Family:

· Artemisia annua (Sweet Wormwood): A plant native to Asia, known for its potent antimalarial compound, artemisinin. It shares a similar traditional use for fevers and has significant medicinal value.

· Calendula officinalis (Pot Marigold): A plant widely used in traditional medicine for its anti-inflammatory and wound-healing properties, similar to the topical uses of B. pilosa.

· Echinacea purpurea (Purple Coneflower): A plant native to North America, renowned for its immunomodulatory properties and use in treating infections, a property also attributed to B. pilosa.

· Taraxacum officinale (Common Dandelion): A plant known for its diuretic and hepatoprotective effects, which are also among the pharmacological activities reported for B. pilosa.

2. Common Names

Scientific Name: Bidens pilosa | English: Blackjack, Spanish Needle, Hairy Beggarticks, Cobbler's Pegs, Railway Daisy, Farmer's Friend, Pitchfork | Hindi: Kumra, Kumur, Bultikna | Manipuri: Sampakpi | Chinese: Gui Zhen Cao (鬼针草) | Spanish: Amor Seco, Saetilla, Picón, Aceitilla, Chipaca | French: Bident Pileux, Sornet, Herbe Villebague | Portuguese (Brazil): Picão Preto | Indonesian: Ajeran, Hareuga | Thai: Puen Noksai, Kee Nok Sai | Vietnamese: Dơn Buốt, Tử Tô Hoang, Quỷ Trâm Thảo | Swahili: Kichoma Mguu

3. Medicinal Uses

Primary Actions: Anti-inflammatory, Antioxidant, Antidiabetic, Antitumor, Antimicrobial

Secondary Actions: Hepatoprotective, Immunomodulatory, Antimalarial, Antipyretic, Wound-healing, Analgesic

Medicinal Parts:

The whole plant, aerial parts (leaves, flowers, seeds, and stems), and roots are the primary parts used medicinally .

· Leaves and Aerial Parts: The most widely used parts in traditional medicine. They are commonly prepared as a decoction, tea, or infusion. They are used for treating inflammation, diabetes, respiratory infections, gastrointestinal disorders, wounds, and as a general health tonic.

· Roots: Used traditionally for their antimalarial and anti-inflammatory properties.

· Whole Plant: Used in various preparations for a wide spectrum of ailments, including fever, dysentery, and hepatitis .

4. Phytochemicals Specific to the Plant and Their Action

The phytochemistry of Bidens pilosa is remarkably diverse, with a complex profile of polyphenols, flavonoids, polyacetylenes, and other bioactive compounds, concentrated in its leaves and roots.

· Flavonoids and Polyphenols: The plant is exceptionally rich in flavonoids and polyphenols, which are responsible for its potent antioxidant and anti-inflammatory activities. Key compounds include quercetin, kaempferol, myricetin, isorhamnetin, and their glycoside derivatives, alongside apigenin, acacetin, and luteolin derivatives . These compounds help neutralise free radicals and reduce oxidative stress.

· Polyacetylenes: These are a group of bioactive compounds, particularly phenylheptatriyne, found in the plant's essential oils, that contribute significantly to its antimicrobial, antimalarial, and anticancer activities .

· Other Bioactive Compounds: The plant contains a wide range of other phytochemicals, including phenolic acids, terpenoids, steroids (including lupene-3,28-diol/botulin and sitostenone), fatty acids (oleic and palmitic acids being major), alkaloids, and coumarins .

5. Traditional and Ethnobotanical Uses Covering the Medicinal Uses

Madhumeha (Diabetes)

Formulation: Leaf decoction or tea.

Preparation and Use: One of the most well-documented traditional uses of B. pilosa is for managing diabetes, reported across multiple continents, including Latin America, Africa, Asia, and Oceania. This independent recurrence suggests a reproducible underlying mechanism . In traditional Chinese medicine, it is used for this purpose, and dried herbs are sold commercially for diabetes management .

Reasoning: The antidiabetic effect is attributed to the high content of flavonoids and polyphenols, which may inhibit aldose reductase, an enzyme involved in diabetic complications, and help regulate blood glucose levels .

Kshata (Wounds) and Skin Disorders

Formulation: Leaf poultice, juice, or topical application.

Preparation and Use: The leaves are used topically to promote wound healing. In many cultures, a poultice of crushed leaves is applied to external wounds, cuts, and burns to prevent infection and speed up tissue regeneration. The juice from fresh leaves is also used for this purpose. It is also used to bathe babies and children in Trinidad and Tobago for its antimicrobial and soothing effects .

Reasoning: Studies have confirmed that leaf extracts promote cell migration in keratinocytes (skin cells), a crucial aspect of wound healing . The wound-healing properties are due to the synergistic action of flavonoids, which possess antimicrobial, antioxidant, and anti-inflammatory properties, effectively combating pathogens and reducing inflammation .

Jwara (Fever) and Shwasa (Respiratory Disorders)

Formulation: Whole plant or leaf decoction.

Preparation and Use: A decoction of the whole plant or leaves is widely used in many traditional systems to treat fevers, colds, flu, coughs, and pharyngitis. This use is documented across Latin America, Africa, and Asia .

Reasoning: The antipyretic (fever-reducing) and antimicrobial properties are attributed to the anti-inflammatory and immunomodulatory effects of various compounds, which help the body fight off infection and reduce fever .

Rakta Vikara and Granthi (Tumours and Cancer)

Formulation: Whole plant extract or decoction.

Preparation and Use: In Cuba and other regions, B. pilosa is known as an antitumor agent . It is used traditionally to address various growths and is one of the documented traditional uses for tumours and cancer .

Reasoning: Modern research has validated this use, showing that the extract suppresses cell proliferation in a concentration-dependent manner against various cancer cell lines, including SNB-19 and SK-MEL-5 . This activity is attributed to its ability to inhibit kinase enzymes and aldose reductase, which are involved in cell proliferation pathways .

6. Healing Recipes, Decoctions, and Preparations

Antidiabetic Leaf Tea

Purpose: To support healthy blood sugar levels.

Preparation and Use:

1. Take one to two teaspoons of dried Bidens pilosa leaves.

2. Steep in a cup of hot water for 10 minutes.

3. Strain and drink the tea twice daily as an adjuvant therapy for diabetes management.

Anti-inflammatory Leaf Decoction

Purpose: To reduce inflammation and support respiratory health.

Preparation and Use:

1. Take a handful of fresh or a small amount of dried leaves.

2. Boil in 500 ml of water for about 10 minutes.

3. Strain and drink the decoction warm, 2-3 times a day, to alleviate symptoms of colds, flu, and pharyngitis.

Wound-Healing Topical Poultice

Purpose: Topical application for minor wounds, cuts, and skin irritations.

Preparation and Use:

1. Crush a handful of fresh B. pilosa leaves into a paste.

2. Apply this paste directly onto the wound or affected area.

3. Cover with a clean cloth and change twice daily.

Culinary Uses of Bidens pilosa

Bidens pilosa is not only a medicinal plant but also a highly nutritious wild food.

1. Leafy Vegetable and Tea

Preparation and Use: The young shoots and leaves, fresh or dried, are used in sauces, teas, and as a cooked vegetable. The United Nations FAO promoted its cultivation in Africa due to its ease of growth, edibility, and safety . They are a good source of protein, fibre, calcium, and carotene.

Flavour Profile: The leaves have a mild, earthy flavour and are a nutritious addition to meals.

Foraging and Preparation Notes

Harvesting: The young shoots must be harvested in spring before they become tough and fibrous. It is crucial to be aware that B. pilosa is a known hyperaccumulator of heavy metals; therefore, harvesting for medicinal or culinary use should be done with caution from clean, unpolluted areas .

Sustainability: As an invasive species, B. pilosa is abundant and easy to find. However, sustainable harvesting is still important to allow for regrowth and to avoid the spread of this invasive weed.

7. In-Depth Phytochemical Profile and Clinical Significance of Bidens pilosa

Introduction

Bidens pilosa, the common blackjack, is a classic example of a plant whose traditional significance is now being thoroughly validated by modern science. While it is often considered a weed, its leaves and roots are a nutritional and medicinal powerhouse. Its therapeutic identity is shaped by a unique and rich profile of flavonoids, polyacetylenes, and other bioactive compounds that exert powerful antioxidant, anti-inflammatory, antimicrobial, and antiproliferative effects. The validation of its traditional use for diabetes, wounds, inflammation, and tumours makes it a highly relevant subject in the search for natural, effective, and safe therapeutic agents.

1. Flavonoids and Polyphenols: The Antioxidant and Anti-inflammatory Arm

Key Compounds: Quercetin, Kaempferol, Myricetin, Isorhamnetin, Apigenin, Luteolin, and their glycoside derivatives.

Quantitative Profile: These flavonoids are abundant, with a high proportion of flavonol aglycones and glycosides . The major content of flavonoids reflects the plant's diverse biological activities.

Actions and Clinical Relevance:

· Anti-inflammatory: The traditional use of B. pilosa for inflammation is strongly supported by the anti-inflammatory activity of its polyphenols. These compounds help reduce the production of pro-inflammatory cytokines .

· Antioxidant: The polyphenols and flavonoids are powerful antioxidants that scavenge free radicals and reduce oxidative stress, which is a primary cause of cellular damage and chronic diseases .

2. Polyacetylenes: The Antimicrobial and Anticancer Arm

Key Compounds: Phenylheptatriyne and other polyacetylene derivatives.

Pharmacological Profile: These compounds are particularly important for their antimicrobial, antimalarial, and anticancer activities. They are a key component of the plant's essential oils .

Actions and Clinical Relevance:

· Antimicrobial and Antimalarial: Polyacetylenes contribute to the plant's traditional use against infectious diseases and malaria .

· Antitumor: They play a role in the plant's antiproliferative and cytotoxic effects against cancer cells .

3. Antiproliferative and Antidiabetic Effects

Key Compounds: Flavonoids (especially quercetin derivatives) and other bioactive compounds.

Pharmacological Profile: The extract has shown significant antiproliferative activity against cancer cell lines and antidiabetic potential by inhibiting aldose reductase .

Actions and Clinical Relevance:

· Antiproliferative: B. pilosa extract suppresses cell proliferation in a concentration-dependent manner against SNB-19 and SK-MEL-5 cell lines. The molecular docking studies show promising binding affinities to kinase and aldose reductase enzymes, which rationalise their antiproliferative activity .

· Antidiabetic: The inhibition of aldose reductase helps in managing diabetic complications, supporting its traditional use for diabetes .

An Integrated View of Healing in Bidens pilosa

· For Diabetes Management: B. pilosa is a prime example of a plant whose traditional use for diabetes is supported by its ability to inhibit enzymes involved in glucose metabolism and diabetic complications, making it a promising nutraceutical.

· For Wound Healing and Skin Health: The potent antimicrobial, antioxidant, and cell-migration-promoting effects of its extracts validate its widespread traditional use as a wound-healing agent .

· For Inflammation and Infections: Its use as an anti-inflammatory and antimicrobial agent is rooted in its rich polyphenol and polyacetylene content, which helps the body fight off infections and manage inflammatory conditions .

· For Overall Wellness: The high nutritional content and its immunomodulatory and antioxidant properties make it a valuable plant for promoting overall health.

Toxicological Profile and Quality Control

Safety Profile: Bidens pilosa is generally considered safe for consumption in culinary doses and traditional medicinal preparations. However, a critical safety concern is its ability to hyperaccumulate heavy metals and arsenic from contaminated soil . Therefore, harvesting for medicinal use must be done with caution. As with any medicinal plant, it should be used under the guidance of a qualified healthcare professional, especially for children and pregnant or nursing women. Comprehensive toxicity assessments are still required .

Quality Control Parameters: The identification of specific flavonoids, such as quercetin derivatives, and polyacetylenes provides a basis for standardising extracts. Analysis by techniques like UPLC-MS/MS and GC-MS ensures the consistency and potency of herbal products .

Conclusion: Bidens pilosa is a truly remarkable plant that seamlessly integrates nutrition, traditional medicine, and modern pharmacological promise. Its journey from a global weed to a valuable medicinal and nutraceutical resource highlights its immense potential. The modern rediscovery and validation of its anti-inflammatory, antioxidant, antimicrobial, and antiproliferative properties is a powerful testament to the enduring wisdom of traditional knowledge. It stands as a highly promising candidate for further research, especially in the fields of diabetology, oncology, and infectious disease, representing a vital link between folk tradition and modern science.

Disclaimer:

Bidens pilosa is generally considered safe for moderate use, but comprehensive safety data, particularly for concentrated extracts and long-term use, are still emerging. A critical safety concern is its ability to hyperaccumulate heavy metals and arsenic from contaminated soil; harvesting must be from clean areas. Pregnant or nursing women should consult a qualified healthcare professional before use. Always consult a qualified healthcare professional before using this plant for medicinal purposes. This information is for educational use only and is not a substitute for professional medical advice.

8. Reference Books, Books for In-depth Study

· "Plant Resources of South-East Asia" (PROSEA) - for taxonomic and distribution details.

· "Journal of Pharmaceutical Innovation" (2025) - for a comprehensive review on phytochemistry and pharmacological potential .

· "Phytochemistry Reviews" (2025) - for a mechanistic insight into pharmacological effects of secondary metabolites .

· "Applied Biochemistry and Biotechnology" (2025) - for a study on quercetin derivatives and antiproliferative activity .

· "Diversity" (2026) - for a review on diverse utilization and sustainable management .

· "Evidence-Based Complementary and Alternative Medicine" (2013) - for a foundational review on botanical properties, traditional uses, phytochemistry, and pharmacology .

9. Further Study: Plants That Might Interest You Due to Similar Medicinal Properties

1. Artemisia annua (Sweet Wormwood)

· Species: Artemisia annua | Family: Asteraceae

· Similarities: A plant from the same family, native to Asia, known for its potent antimalarial compound, artemisinin, and for its traditional use for fevers. It shares a similar anti-inflammatory and antipyretic profile.

2. Achillea millefolium (Yarrow)

· Species: Achillea millefolium | Family: Asteraceae

· Similarities: A herbaceous perennial native to temperate regions, known for its aerial parts' wound-healing and anti-inflammatory properties. Like B. pilosa, it is rich in flavonoids and has strong antimicrobial and antioxidant activities.

3. Calendula officinalis (Pot Marigold)

· Species: Calendula officinalis | Family: Asteraceae

· Similarities: A plant widely used in traditional medicine for its anti-inflammatory and wound-healing properties, similar to the topical uses of B. pilosa.

4. Taraxacum officinale (Common Dandelion)

· Species: Taraxacum officinale | Family: Asteraceae

· Similarities: A plant known for its diuretic and hepatoprotective effects, which are also among the pharmacological activities reported for B. pilosa.

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