Login Logout
Jump to: navigation, search

Bidens pilosa


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.<ref name=pier>Bidens pilosa. Pacific Island Ecosystems at Risk (PIER). USFS.</ref>Template:Citation needed It is a tall branched weed with thin yellow flowers that develop into a cluster of barbed fruits.<ref>Template:Cite web</ref> Its many common names include black-jack,<ref name=BSBI07>Template:Cite web</ref> beggar-ticks, cobbler's pegs, farmer's friends<ref>https://www.survival.org.au/bf_bidens_pilosa.php</ref> and Spanish needle.<ref name=pier/><ref>Template:Cite web</ref><ref>Flora of China, 鬼针草 gui zhen cao Bidens pilosa Linnaeus, Sp. Pl. 2: 832. 1753. </ref><ref>Altervista Flora Italiana, Forbicina pelosa, Bidens pilosa L. includes photos and European distribution map</ref><ref>Atlas of Living Australia, Bidens pilosa L., Cobbler's Peg</ref> The fruits are like short, stiff hairs. They get stuck in feathers, fur, or socks, etc.<ref>Template:Cite web</ref><ref>Template:Cite web</ref> This bur is widespread throughout the warmer regions of the world.<ref>Template:Cite web</ref> Its little black fruits 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.<ref>Template:Cite web</ref> Each fruit has two to four barbed spines.<ref>Template:Cite web</ref> 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.<ref name="survival.org.au">Template:Cite web</ref><ref>Template:Cite web</ref><ref>Template:Cite web</ref> Although this plant is considered a weed in some parts of the world, in other parts it is a source of food or medicine.<ref name="prota">Grubben, G. J. H. & O. A. Denton. (2004) Plant Resources of Tropical Africa 2. Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen.</ref> For example, it is reportedly widely eaten in Africa,<ref name="survival.org.au"/> and in Vietnam, during the Vietnam War soldiers adopted the herb as a vegetable, which lead to it being known as the "soldier vegetable".<ref>Template:Cite book</ref>


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.<ref name=r>Flora of North America, Bidens pilosa Linnaeus, Sp. Pl. 2: 832. 1753. </ref>

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 fruits are transported by animals. This mechanism has helped the plant become a noxious weed in temperate and tropical regions.<ref name=r/>

Common names

This plant has many common names in different regions and languages, including:<ref name=pier/>

Traditional uses

In traditional Chinese medicine, this plant is considered a medicinal herb, called xian feng cao (Template:Zh).Template:Citation needed. In traditional Bafumbira medicine, this plant is applied on a fresh wound and is known to be a medicinal herb, called inyabalasanya.Template:Citation needed


Almost two hundred compounds have been isolated from B. pilosa, especially polyacetylenes and flavonoids.<ref>Silva, F. L., et al. (2011). Compilation of secondary metabolites from Bidens pilosa. Molecules 16(2), 1070-1102.</ref> The plant contains the chalcone okanin<ref>Presence of Compounds in Picao preto (Bidens pilosa). Raintree Nutrition.</ref> and ethyl caffeate, a hydroxycinnamic acid.<ref name=Chiang>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. Template:PMID</ref>

Extracts of B. pilosa suppressed the growth of isolated adult T-cell leukemia cells in vitro.<ref>Nakama, S., et al. (2011). .Anti-adult T-cell leukemia effects of Bidens pilosa. International Journal of Oncology 38(4), 1163-73. Template:PMID</ref>

See also



External links