''Bidens pilosa'' is an annual species of

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

flowering plant in the daisy family

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

. Its many common names include hitch hikers, black-jack, beggarticks, farmer's friends and Spanish needle, but most commonly referred to as cobblers pegs. It is native to the

Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...

but is widely distributed as an

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

in other regions including

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

and the

Pacific Islands The Pacific islands are a group of islands in the Pacific Ocean. They are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of several ...

,''Bidens pilosa''.
Pacific Island Ecosystems at Risk (PIER). USFS. and is classified as an

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

in some regions of the world.

Description

''Bidens pilosa'' is a branched annual

forb A forb or phorb is a herbaceous flowering plant that is not a graminoid (grass, sedge, or rush). The term is used in botany and in vegetation ecology especially in relation to grasslands and understory. Typically, these are eudicots without woo ...

of gracile

habit A habit (or wont, as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously. A 1903 paper in the '' American Journal of Psychology'' defined a "habit, from the standpoint of psychology, ...

, growing up to 1.8 meters tall. It grows aggressively on disturbed land and often becomes weedy. The leaves are all oppositely arranged and range from simple to

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ...

in form, the upper leaves with three to five dentate,

ovate Ovate may refer to: * Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe * Ovates, one of three ranks of membership in the Welsh Gorsedd * Vates or ovate, a term for ancient Celtic bards ...

-to-

lanceolate The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...

leaflets. The petioles are slightly winged.Flora of North America, ''Bidens pilosa'' Linnaeus, Sp. Pl. 2: 832. 1753.
/ref> The plant may flower at any time of the year, but mainly in summer and autumn in temperate regions. The flowers are small heads borne on relatively long peduncles. The heads consist of about four or five broad white

ray florets Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger fa ...

(ligules), surrounding many tubular yellow

disc floret Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger fa ...

s without ligules that develop into barbed fruits. The fruits are slightly curved, stiff, rough black rods, tetragonal in cross section, about 1 cm long, typically with two to three stiff, heavily barbed awns at their

distal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

ends. The

infructescence In botany, infructescence (fruiting head) is defined as the ensemble of fruits derived from the ovaries of an inflorescence. It usually retains the size and structure of the inflorescence. In some cases, infructescences are similar in appearance ...

s form stellate spherical burrs about one to two centimeters in diameter. The barbed spines of the achenes get stuck in the feathers, fur, fleeces, clothing, etc. of people or animals that brush against the plant. It is an effective means of

seed dispersal In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

by zoochory, as the fruits are transported by animals. This mechanism has helped the plant become a

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is harmful to agricultural or horticultural crops, natural habitats or ecosystems, or humans or lives ...

in temperate and tropical regions.

Distribution

The species is native to tropical America, widely naturalized throughout the warm temperate and tropical regions of the world. A weed of gardens, woodlands and waste areas.

Common names

Its many English common names include black-jack, beggarticks, hairy beggarticks, cobbler's pegs, devil's needles, hairy bidens, Spanish needle, farmers friend, Devils Pitchfork, hitch hikers and sticky beaks.

Uses

Although ''Bidens pilosa'' is primarily considered a

weed A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Pla ...

, in many parts of the world it is also a source of

food Food is any substance consumed by an organism for Nutrient, nutritional support. Food is usually of plant, animal, or Fungus, fungal origin and contains essential nutrients such as carbohydrates, fats, protein (nutrient), proteins, vitamins, ...

and

alternative medicine Alternative medicine refers to practices that aim to achieve the healing effects of conventional medicine, but that typically lack biological plausibility, testability, repeatability, or supporting evidence of effectiveness. Such practices are ...

.Grubben, G. J. H. & O. A. Denton. (2004) Plant Resources of Tropical Africa 2. Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen. The leaves have a resinous flavor, are eaten raw or in stews or dried for storage. In eastern Africa it is used for medicinal purposes for its healing power for wounds. During the Vietnam War, soldiers adopted the herb as a vegetable, which led to it being known as the "soldier vegetable". It is susceptible to hand weeding if small enough. Even then it must be bagged, and thick mulches may prevent it from growing. Extracts from ''Bidens pilosa'' are used in Southern Africa for malaria.

Chemistry

Almost 200 compounds have been isolated from ''B. pilosa'', especially

polyacetylene Polyacetylene (IUPAC name: polyethyne) usually refers to an organic polymer with the repeating unit . The name refers to its conceptual construction from polymerization of acetylene to give a chain with repeating olefin groups. This compound is ...

s and

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s.Silva, F. L., et al. (2011). Compilation of secondary metabolites from ''Bidens pilosa''. ''Molecules'' 16(2), 1070-1102. The plant contains

ethyl caffeate Ethyl caffeate is an ester of a hydroxycinnamic acid, a naturally occurring organic compound. Natural occurrences It can be found in ''Bidens pilosa'', in ''Polygonum amplexicaule var. sinense''. It is also found in Huáng bǎi, one of the fif ...

, a

hydroxycinnamic acid Hydroxycinnamic acids (hydroxycinnamates) are a class of aromatic acids or phenylpropanoids having a C6–C3 skeleton. These compounds are hydroxy derivatives of cinnamic acid. In the category of List of phytochemicals in food, phytochemicals tha ...

.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.

References

External links

Plant Resources of Tropical Africa Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars f ...

(PROTA). Retrieved on 12 April 2010. {{Taxonbar, from=Q814421

pilosa The Order (biology), order Pilosa is a clade of xenarthran placental mammals, native to the Americas. It includes anteaters and sloths (which include the extinct ground sloths). The name comes from the Latin word for "hairy". Origins and taxon ...

Flora naturalised in Australia Flora of Northern America Plants described in 1753 Taxa named by Carl Linnaeus