Bidens pilosa (PROSEA)
- Protologue: Sp. pl. 2: 832 (1753).
Bidens sundaica Blume (1826), Bidens leucorrhiza (Lour.) DC. (1836), Bidens pilosa L. var. minor (Blume) Sherff (1925).
- Black jack (En). Sornet (Fr)
- Indonesia: ajeran, hareuga (Sundanese), jaringan, ketul (Javanese)
- Malaysia: kancing baju, pau-pau pasir, keroten
- Papua New Guinea: ivu na mag (Gunantuna, New Britain), rakot (Kurtatchi, Bougainville)
- Philippines: dadayem (Ibanag), burburtak (Ilocano), pisau-pisau (Bisaya)
- Thailand: puen noksai (northern), kee nok sai, yaa koncham khaao (central)
- Vietnam: dơn buốt, tử tô hoang, qủy trâm thảo.
B. pilosa originates from tropical America but is now distributed and naturalized as a weed in most tropical and subtropical regions of the world, even sometimes extending into some temperate areas. In South-East Asia it is common in many places, except in Kalimantan and the Moluccas.
B. pilosa is widely used in traditional medicine against numerous complaints, often to soothe pain. An infusion or decoction, or the juice of the leaves is used against coughs, angina, headache, fever, diabetes, constipation, diarrhoea, intestinal worms, stomach-ache, toothache, poisoning, muscular pains and as a bath to treat itching and rheumatic pains. Crushed leaves, sometimes heated over a fire, are applied on the skin to treat inflammations, burns, on wounds to stop bleeding and on ulcers. In Papua New Guinea, crushed flower-heads are often used externally to extract pus from boils. A decoction of the leaves or of the roots is applied on eyelids to treat eye infections. A tincture of the flowers and leaves is used as a mouthwash against toothache. Roots are chewed against toothache. In Indonesia, the Philippines and Africa, young shoots and young leaves are eaten raw or cooked as a vegetable. Leaves as vegetable in the daily diet have been observed to prevent goitre in the Philippines. The plant is sometimes used as fodder.
An annual, usually erect herb up to 1(-2) m tall, stem 4-angled, glabrous or sparsely pubescent; leaves opposite, pinnately 3-5-lobed, occasionally the lower and/or upper leaves simple, up to 15(-20) cm long, glabrous or sparsely pubescent on both surfaces, margin usually serrate or crenate-serrate, the segments ovate to ovate-lanceolate, the terminal one largest, petiolate; capitula solitary or in lax paniculate cymes, usually radiate, 5-12 mm broad, outer involucral bracts 7-10, spathulate, reflexed at anthesis, 3-4 mm × 0.5-0.8 mm, 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 linear, 4-6-ribbed, 4-13 mm long, with 2-3(-5) retrorsely barbed bristles of 2-4 mm long. B. pilosa is a very common weed of sunny, often disturbed places like roadsides, fields, thickets and along watercourses, up to 2500 m altitude.
52, 53, 85, 97, 111, 168, 180, 184, 202, 224, 332, 350, 458, 475, 580, 597, 598, 599, 610, 614, 663, 818, 852, 920, 937, 1035, 1124, 1126, 1128, 1178, 1329, 1380, 1386, 1543, 1551, 1572.
D.S. Alonzo & J.W. Hildebrand