Taxonomic name: Bidens pilosa L.
Synonyms: Bidens leucantha (L.) Willd., Bidens leucantha Willd. var. sundaica (Blume) Hassk., Bidens odorata, Bidens sundaica (Blume), Coreopsis leucantha L.
Common names: abissawa (Ivory Coast), acetillo (Spanish), adzrskpi (Ivory Coast), agberi-oku (Sierra Leone), akesan (Nigeria), alonga (Ivory Coast), alongoï (Ivory Coast), amonoablanfè (Ivory Coast), amor seco (Spanish), anansee mpaane (Ghana), anasipagné (Ivory Coast), arponcito (Spanish), aseduro (Ghana), asta de cabra (Spanish), batimadramadramatakaro (Fijian), beggar's tick (English), bident hérissé (French), bident poilu (French), bidente pilosa (Spanish), black fellows (English), black jack (English), broom stick (English), broom stuff (English), cacha de cabra (Spanish), cadillo (Spanish), carrapicho-deagulha (Portuguese), cobbler's peg (English), dada (Sierra Leone), dadayem (Ibatan), devil's needles (English), diaani (Ivory Coast), diandu (Ivory Coast), dinenkui (Ivory Coast), dwirantwi (Ghana), dzani pipi (Ghana), eyinata (Nigeria), fisi'uli (Tongan), gonoretti (Ivory Coast), gyinantwi (Ghana), hairy beggar ticks (English), herbe d'aiguille (French), herbe villebague (French), hierba amarilla (Spanish), iréné (Ivory Coast), iuna (Ivory Coast), kamik tuarongo (Maori), kandane (Sierra Leone), kete kete (Nigeria), ki (Hawaiian), ki nehe (Hawaiian), ki pipili (Hawaiian), kichoma mguu (Swahili), kichoma nguo (Swahili), kiradale (Ivory Coast), klakuo, kofetoga (Niuean), kofetonga (Niuean), kokosa (Ivory Coast), ko-sendagusa (Japanese), kukwe kwo (Ivory Coast), kurofidie (Ghana), lebason (Ivory Coast), légué (Ivory Coast), manamendigo (Ivory Coast), masquia (Spanish), matua kamate (Fijian), mazote (Spanish), mbatikalawau (Fijian), mbatimandramandra (Fijian), nana (Sierra Leone), nangua (Ivory Coast), nanguadian (Ivory Coast), nehe (Hawaiian), nguad, niani (Liberia), nidul-lif (Sierra Leone), niroa (Maori), papunga chipaca (Spanish), passoklo (Ivory Coast), pega-prga (Spanish), perca (Spanish), pétéoré (Ivory Coast), picão-preto (Portuguese), pilipili, piquants noirs (French), piripiri (Maori), piripiri, piripiri kerekere (Maori), piripiri niroa (Maori), pisau-pisau, puriket, rosilla (Spanish), sanyi (Sierra Leone), sanyina (Sierra Leone), sirvulaca (Spanish), sornet (French), sosolé (Ivory Coast), Spanish needle (English), tabason (Ivory Coast), tagiaani (Ivory Coast), tebasson (Ivory Coast), tombo-maga (Sierra Leone), zagaï zagagbé (Ivory Coast), zagoi ini (Ivory Coast), zebeyuzébogue (Ivory Coast), zegbei zegbagwè (Ivory Coast), zikilli wissi, Zweizhan (German)
Organism type: herb
Bidens pilosa is a cosmopolitan, annual herb which originates from tropical and Central America. Its hardiness, explosive reproductive potential, and ability to thrive in almost any environment have enabled it to establish throughout the world. Generally introduced unintentionally through agriculture or sometimes intentionally for ornamental purposes, B. pilosa is a major crop weed, threat to native fauna, and a physical nuisance.
Bidens pilosa is an erect, annual herb which stands from 0.3-2 m high and bears opposite, pinnately compound, broadly ovate, (3-)5-9-lobed leaves 3-20 cm long and 2.5-12 cm wide. Leaf segments ovate to lanceolate lobed or bilobed at the base with margins crenate-serrate and apices acute. Stems are reddish tinged; 4-angled, simple, or branched. Heads solitary or in lax paniculate cymes at the ends of the main stem and lateral branches, usually radiate, 5 – 12 mm broad. Heads with 2 rows of involucral bracts, outer ones 7-10, spathulate, reflexed at anthesis, 3-4 mm long, inner ones ovate lanceolate; ray flowers absent or 4-8, sterile, corolla 7-15 mm long, white to yellow or pinkish, disk flowers with 3.5 – 5 mm long, yellow corolla. Achenes are black, 4-8 ribbed, linear, 6-16 mm long, with 2-3(-5) retrorsely barbed bristles of 2-4 mm long (Aluka, undated; PIER 2007).
agricultural areas, natural forests, planted forests, range/grasslands, riparian zones, ruderal/disturbed, scrub/shrublands, urban areas, wetlands
Bidens pilosa is a hardy weed capable of invading a vast range of habitats ranging from moist soil, sand, limerock, or dry, infertile soil and low to high altitudes of up to 3,600 m. It thrives in disturbed areas, high sunlight, and moderately dry soils, but is known to invade grassland, heathland, forest clearings, wetlands, plantations, streamlines, roadsides, pasture, coastal areas, and agriculture areas. B. pilosa is capable of surviving severe droughts with a required annual rainfall range is 500-3500 mm. It is tolerant to a pH range of 4-9 and high salinities of up to 100 mM NaCl. It prefers temperatures above 15°C and below 45°C but is tolerant to frosts with roots capable of withstanding and regenerating after temperatures as low as -15°C. B. pilosa is not fire tolerant but is known to quickly invade burnt areas (PIER, 2007; Aluka, undated; DPI, 2008).
Bidens pilosa is a problematic species for many reasons throughout its range. A troublesome weed to at least 30 crops in over 40 countries, B. pilosa is known to significantly reduce crop yields. One study found that dry bean, Phaseolus vulgaris, harvests were reduced by 48% in Uganda and 18-48% in Peru due to impacts by B. pilosa. It forms dense stands that can out compete, out grow, and eliminate crop and native vegetation, specifically the lower vegetative strata, over large areas. B. pilosa prevents the regeneration of these plants as well, given its allelopathic properties. Leaf and root extracts are known to significantly suppress germination and seedling growth of many plants and are believed to remain active throughout decomposition. Furthermore, B. pilosa grows three times faster than similar plant species. All of these properties render it a quite formidable competitor.
Its thick stands impede access to roads, trails, and recreational areas, are a nuisance to travellers and tourists, and inflict damage to pavements and walls. Its burrs are a nuisance to people, as well as, sheep and other fleece producing livestock. The burrs are also a troublesome seed contaminant as they are difficult to separate. Bidens pilosa is also a host and vector to harmful parasites such as Root knot nematodes (Meloidogyne sp.) and Tomato spotted wilt virus (Schlerotinia sclerotiorum) (DPI, 2008; Mvere, 2004).
Bidens pilosa is used as a medicinal plant in areas of Africa, Asia, and tropical America. Its roots, leaves, and seeds are reported to have antibacterial, antidysenteric, anti-inflammatory, antimicrobial, antimalarial, diuretic, heptoprotective, and hypotensive properties. In Africa, B. pilosa is used to treat headaches, ear infections, hangovers, diarrhoea, kidney problems, malaria, jaundice, dysentery, burns, arthritis, ulcers, and abdominal problems. It is also used as an anaesthetic, coagulant, and treatment to ease child birth. In sub-Saharan Africa, its fresh or dried shoots and young leaves are eaten as a leaf vegetable, especially in times of food scarcity. B. pilosa is also an ingredient of sauces eaten with many staple foods there (Mvere, 2004).
Native range: Antigua and Barbuda, Argentina, Australia, Barbados, Belize, Bolivia, Brazil, Chile, Coasta Rica, Columbia, Cuba, Dominica, Dominican Republic, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Monteserrat, Nicaragua, Panama, Peru, Puerto Rico, St. Kitts, St. Lucia, St. Vincent and Grenadines, Suriname, Uruguay, Venezuela, Virgin Islands (USA)
Known introduced range: American Somoa, Austria, Azores, Belgium, Benin, Botswana, British Indian Ocean Territory (BIOT), Cambodia, Cameroon, Canada, Canarias, China, Christmas Island (Indian Ocean), Cook Islands, Congo, Cote d' Ivoire, Cyprus, Czech Republic, England, Estonia, Federated States of Micronesia (FSM), Fiji, France, French Polynesia, Gaum, Greece, Indonesia, Israel, Italy, Japan, Kenya, Kiribati, Liberia, Madeira, Mauritius, Malawi, Malaysia, Marshall Islands, Mzoambique, New Caledonia (Nouvelle Calédonie), New Zealand, Nigeria, Niue, Norfolk Island, Northern Mariana Islands, Palau, Papua New Guinea, Philippines, Pitcairn, Portugal, Samoa, Scotland, Seychelles, Sierra Leone, Slovenia, Soloman Islands, Taiwan, Tanzania, Thailand, Tonga, Uganda, United Kingdom (UK), United States (USA), United States Minor Outlying Islands, Vanuatu, Viet Nam (Vietnam), Wallis and Futuna, Zambia, Zimbabwe
Introduction pathways to new locations
Agriculture: Bidens pilosa has been introduced to many new locations by man for agricultural or ornamental purposes (Carlquist, 1966).
For ornamental purposes: Bidens pilosa has been introduced to many new locations by man for agricultural or ornamental purposes (Carlquist, 1966).
Local dispersal methods
For ornamental purposes (local): People have been known to plant Bidens pilosa on vacant land for ornamental purposes (Zunsontiporn, undated).
On animals: The burred seeds of Bidens pilosa readily attach to clothing, fur, and feathers for dispersal (PIER, 2007).
On clothing/footwear: The burred seeds of Bidens pilosa readily attach to clothing, fur, and feathers for dispersal (PIER, 2007).
Water currents: Bidens pilosa seeds may also be dispersed by water currents (PIER, 2007).
Physical: Bidens pilosa is susceptible to hand weeding. Germination may be prevented by mulches if they are thick enough (PIER, 2007).
Chemical: B. pilosa is susceptable to several types of herbicides. Residual herbicides: diuron, bromacil, atrazine, simazine, ropazine, hexazinone, oryzalin, and ametryn; translocated herbicides: 2,4-D, glyphosate, amitrole, metribuzin, and dicamba; and contact herbicides bentazone, diquat, and paraquat have all been evaluated as effective means of controlling B. pilosa when applied at standard rates. B. pilosa is thought susceptible to the majority of broad-leafed plant herbicides (PIER, 2007).
Sexual by self or cross-pollination. A single plant may produce 3,000-6,000 seeds per year which are spread by attaching to animals, birds, and people or dispersal by wind and water. Its full reproductive cycle may be completed in 57-70 days and be completed 5-6 times a years in some areas. Seeds are reported to have no dormancy, remain viable for 5-6 years, and a 74% germination rate in the field (PIER, 2007; Zungsontiporn, undated; DPI, 2008)
Bidens pilosa grows quickly. Plants flower 4 months after germination and produce mature seeds 4 weeks after flowering. Plants typically bear 80 flower heads with seeds with potential production of 3000 plants in a generation and 4 generations per year (DPI, 2008; Mvere, 2004; PIER, 2007).
Reviewed by: Johan van Valkenburg, Dutch Plant Protection Service.
Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Monday, 30 August 2010