Common Name: Beggar's Ticks

General Information

Bidens pilosa is an annual plant producing an erect, much-branched stem up to 100cm tall, though the plant can often flower, seed and then die when much smaller.
The plant is gathered from the wild for local use as a food and medicine. In parts of Africa, the plant is allowed to remain as a weed in cultivated ground, and it is also sometimes cultivated[].
Bidens pilosa is a hardy weed capable of invading a vast range of habitats at elevations from sea level up to 3,600 metres[]. It thrives in disturbed areas, high sunlight, and moderately dry soils, it is known to invade grassland, heathland, forest clearings, wetlands, plantations, streamlines, roadsides, pasture, coastal areas, and agriculture areas[]. Bidens pilosa is a problematic species for many reasons throughout its range. A troublesome weed to at least 30 crops in over 40 countries, it is known to significantly reduce crop yields by almost 50% in some cases. It forms dense stands that can out compete, out grow, and eliminate crop and native vegetation, specifically the lower vegetative strata, over large areas. It 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, it 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 and wild life. The burrs are also a troublesome seed contaminant as they are difficult to separate from grain. The plant is also a host and vector to harmful parasites Root knot nematodes (Meloidogyne sp.) and Tomato spotted wilt virus (Schlerotinia sclerotiorum)[].

Known Hazards

The roots, leaves and flowers are strongly phototoxic, the achenes weakly so[]. Substances isolated from the leaves can kill human skin in the presence of sunlight at concentrations as low as 10ppm[].

Botanical References

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Range

Throughout S. America, C. America and the Caribbean to southern N. America. Widely naturalized elsewhere.

Habitat

Damp lowland fields and wasteland, North and Kermadec Islands[]. Moist, open neglected places at elevations of 700 - 2000 metres in Nepal[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	0.60 m
Pollinators	Bees, Hoverflies, Self
Self-fertile	Yes
Cultivation Status	Cultivated, Semi-cultivated, Wild

Cultivation Details

Bidens pilosa is a pantropical weed, often also extending into the temperate zone, where it can be found at elevations up to 3,600 metres[]. It prefers temperatures above 15°c and below 45°c, but is tolerant to frosts and has roots capable of withstanding and regenerating after short-lived temperatures falling as low as -15°c[]. It can succeed in areas where the mean annual rainfall is in the range 500 - 3,500mm[].
Succeeds in any moderately fertile moisture-retentive soil in full sun[]. Plants can grow in a vast range of habitats ranging from moist soil, sand, lime rock, or dry, infertile soil[]. Plants are tolerant of a pH range from 4 - 9 and also highly saline soils[]. Plants can tolerate severe droughts[].A fast-growing plant, flowering starts 6 weeks after emergence and continues until plant senescence 2 - 3 months later[].
The plants are ready for harvesting within 4 - 6 weeks of emergence, before seed setting. Harvesting is done by hand picking, cutting or uprooting. If the plants are topped, a second harvest can follow after 2 weeks. Up to 6 harvests are possible[]. There may be 4 or 5 successive plantings within a year[]. If it is grown for harvesting the leaves as antimalaria medicine, deflowering is necessary to retard senescence and maintain growth[].
Yields of up to 30 tonnes per hectare can be obtained[].
The plant is not fire tolerant but is known to quickly invade burnt areas by means of its seeds[].

Edible Uses

Leaves and young shoots - raw or cooked[, ]. A resinous flavour[]. Added to salads or steamed and added to soups and stews, they can also be dried for later use[]. A good source of iodine[]. A nutritional analysis is available[].
Young shoot tips are used to make a tea[].

Medicinal

Beggar's ticks is commonly used in traditional medicine in the treatment of a wide range of complaints, often being used to soothe pain[].
The leaves are considered to be alterative, antiinflammatory, carminative, styptic and vermifuge[]. Taken as an infusion or decoction, or as a juice of the leaves, it is used to treat a range of digestive problems, including stomach aches, bloat, constipation, diarrhoea, and intestinal worms; as well as coughs, angina, headache, fever, diabetes, muscular pains etc[, ]. Eating the leaves as a vegetable in the daily diet has been observed to prevent goitre in the Philippines[].
A juice made from the leaves is used to dress wounds and ulcers[, ]. The leaf sap is used for treating burns, sores, itchy skin etc, and as an eyewash for itching and tired eyes[, ].

The whole plant is antirheumatic, it is also used in enemas to treat intestinal ailments[]. An infusion is used to treat diabetes, thrush, the oesophagus and stomach-ache[].

The roots are used to treat constipation and malaria[]. They are chewed to relieve toothache[].

The crushed flower-heads are used externally to extract pus from boils[].

A tincture of the flowers and leaves is used as a mouthwash against toothache[].

Substances isolated from the leaves are bactericidal and fungicidal, they are used in the treatment of thrush and candida[].
Extracts of the plant have shown antimalarial activity both in vitro and in vivo. The crude ethanol extract (50 μg/ml) causes up to 90% inhibition of Plasmodium falciparum growth in vitro, compared with 86 - 94% inhibition for the chloroform fraction and 68 - 79% for the butanol fraction (both at 50 μg/ml).[].
Phenylacetylenes and flavonoids have been found in the ethanol extract from the leaves and the roots[]. The results indicate that the antimalarial activity of the plant may be attributed to the presence of acetylene compounds. The direct therapeutic usefulness of these compounds seems limited, since they are easily oxidized by air and light[].
A number of polyacetylenes are toxic to yeasts and some bacteria. This compound is an active antiparasitic and exhibited marked insecticidal activity with LC50 of 204 ng/cm2 for the first instar larvae of the fall army worm (Spodoptera frugiperda)[].
The polyacetylene 7-phenylhepta-2,4,6-triyne in combination with light is reported to be phytotoxic to fibroblast cells[].
In addition to the acetylenes, other compounds such as phytosterols, triterpenes and caffeic acid are also reported from the plant[].
The main flavonoids from leaf extracts are aurones and chalcones. Since friedelin and friedelan-3β-ol, as well as several flavonoids have anti-inflammatory properties, their detection in extracts of the plant, together with the presence of the described acetylenes, may explain the use of Bidens pilosa in traditional medicine, especially for treating wounds, against inflammations and against bacterial infections of the gastrointestinal tract[].
The ethanolic extract of Bidens pilosa showed a high inhibition of prostaglandin synthesis in an in vitro assay for cyclo-oxygenase inhibitors. The methanol extract showed radio-protective activity for bone marrow. Besides the above-mentioned pharmacological activity, antihyperglycaemic, immunomodulator, anti-ulcer and hypotensive activity are also reported[].

Other Uses

The plant is collected for the extraction of natural dyes[].

The root is washed and dried, then used as a painting brush[].

Propagation

Seed - sow early spring in a greenhouse and only just cover the seed. The optimum temperature for germination is 25 - 30°c, temperatures below 15°c and above 45°c are not favourable[]. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in May.
Alternatively, a sowing in situ in mid to late spring can be tried.