Hairy Beggarticks (Bidens pilosa) (Linnaeus 1753) |
Synonyms: Bidens alba, B. alba var. radiata, B. odorata, B. pilosa var. radiata (see The Plant List for more details) |
Bidens pilosa is an annual herb native to Mexico, Central and South America, and the Caribbean; it was widely introduced to North America, Eurasia, Africa, Australia, and the Pacific Islands. This is a ruderal species which thrives in almost any disturbed habitats, including riparian zones, shrublands, grasslands, wetlands, woodlands, agricultural and urban areas; 10-1,900 m. The leaves are ovate to lanceolate. Flowers are borne in small heads bearing 4-5 white ray florets, surrounding many tubular yellow disc florets. The fruits are rough black rods with 2-3 stiff barbed awns. The barbs catch onto fur or clothing, allowing for effective seed dispersal. The plant may flower at any time of the year, but in temperate regions mainly in summer and autumn.