Bidens pilosa

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Bidens pilosa[1]
Bidens pilosa var minor001.jpg
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Genus: Bidens
Species: B. pilosa
Binomial name
Bidens pilosa
L. 1753
Immature fruiting head

Bidens pilosa is a species of flowering plant in the aster family. It is native to the Americas but it is known widely as an introduced species of other regions, including Eurasia, Africa, Australia, and the Pacific Islands.[3] It is a tall branched weed with thin yellow flowers that develop into a cluster of barbed seeds.[4] Its many common names include black-jack,[5] beggar-ticks, cobbler's pegs, and Spanish needle.[3][6][7][8][9] The seeds are like short, stiff hairs. They get stuck in feathers, fur, or socks, etc.[10][11] This bur is widespread throughout the warmer regions of the world.[12] Its little black seeds hook onto clothes or horses and thereby the bur spreads itself around. It is susceptible to hand weeding if small enough, even then must be bagged, and thick mulches may prevent it from growing.[13] Each seed has two barbed spines.[14] A weed of gardens, woodlands, and waste areas, a person who brushes against it will end up covered in the burs and need to pick them off one by one.[15][16][17] Although this plant is considered a weed in some parts of the world, in other parts it is a source of food or medicine.[18] For example, it is reportedly widely eaten in Africa.[19]


Bidens pilosa is an annual forb of gracile habit, growing up to 1.8 meters tall. It grows aggressively on disturbed land and often becomes weedy. The leaves are oppositely arranged and pinnate in form with three to five dentate, ovate-to-lanceolate leaflets. The petioles are slightly winged.[6]

The plant may flower at any time of the year, but in temperate regions it blooms mainly in summer and autumn. Flowers are borne in small heads on relatively long peduncles. The heads bear about four or five broad white ray florets, surrounding many tubular yellow disc florets. The fruits are slightly curved, stiff, rough black rods, tetragonal in cross section, about 1 cm long, with typically two to three stiff, heavily barbed awns at their distal ends. The infructescences form stellate spherical burrs about one to two centimeters in diameter. The barbed awns catch onto fur or clothing, and can injure flesh. It is an effective means of seed dispersal by zoochory, as the seeds are transported by animals. This mechanism has helped the plant become a noxious weed in temperate and tropical regions.[6]

Common names[edit]

This plant has many common names in different regions and languages, including:[3]

Traditional uses[edit]

In traditional Chinese medicine, this plant is considered a medicinal herb, called xian feng cao (Chinese: 咸豐草).[citation needed]. In traditional Bafumbira medicine, this plant is applied on a fresh wound and is known to be a medicinal herb, called inyabalasanya.[citation needed]


Almost two hundred compounds have been isolated from B. pilosa, especially polyacetylenes and flavonoids.[21] The plant contains the chalcone okanin[22] and ethyl caffeate, a hydroxycinnamic acid.[23]

Extracts of B. pilosa suppressed the growth of isolated adult T-cell leukemia cells in vitro.[24]

See also[edit]


  1. ^
  2. ^ The Plant List, Bidens pilosa L.
  3. ^ a b c Bidens pilosa. Pacific Island Ecosystems at Risk (PIER). USFS.
  4. ^ [1]
  5. ^ "BSBI List 2007" (xls). Botanical Society of Britain and Ireland. Retrieved 2014-10-17. 
  6. ^ a b c Flora of North America, Bidens pilosa Linnaeus, Sp. Pl. 2: 832. 1753.
  7. ^ Flora of China, 鬼针草 gui zhen cao Bidens pilosa Linnaeus, Sp. Pl. 2: 832. 1753.
  8. ^ Altervista Flora Italiana, Forbicina pelosa, Bidens pilosa L. includes photos and European distribution map
  9. ^ Atlas of Living Australia, Bidens pilosa L., Cobbler's Peg
  10. ^ [2]
  11. ^ [3]
  12. ^ [4]
  13. ^ [5]
  14. ^ [6]
  15. ^ [7]
  16. ^ [8]
  17. ^ [9]
  18. ^ Grubben, G. J. H. & O. A. Denton. (2004) Plant Resources of Tropical Africa 2. Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen.
  19. ^ [10]
  20. ^ "Plant Use Details of Bidens pilosa". Landcare Research. Retrieved November 20, 2012. 
  21. ^ Silva, F. L., et al. (2011). Compilation of secondary metabolites from Bidens pilosa. Molecules 16(2), 1070-1102.
  22. ^ Presence of Compounds in Picao preto (Bidens pilosa). Raintree Nutrition.
  23. ^ Chiang, Y., et al. (2005). Ethyl caffeate suppresses NF-κB activation and its downstream inflammatory mediators, iNOS, COX-2, and PGE2 in vitro or in mouse skin. Br J Pharmacol. 146(3) 352–63. PMID 16041399
  24. ^ Nakama, S., et al. (2011). .Anti-adult T-cell leukemia effects of Bidens pilosa. International Journal of Oncology 38(4), 1163-73. PMID 21318218

External links[edit]