Graines Herbe à aiguilles, Sornet, Bidens pilosa

hitch hikers, black-jack, beggarticks, bidens pilosa |

Bidens Pilosa is an annual species of herbaceous plants with flowers of the Marguerites family Asteraceae . Its many common names include Auto hikers -Stop, Black -Jack , Beggarticks , Friends of Farmers and The Spanish needle , but most often called Piquets of Cordonniers . He is from Americas but is widely distributed as that Introduced Estece in other regions of the world, notably Eurasia , Africa , Australia , South America and Pacific islands .

10 seeds

Bidens Pilosa is an annual herbaceous Ramified of Port Gracile , reaching 1.8 meters high. It grows aggressively on the disturbed lands and often becomes a bad grass. The leaves are all arranged in an opposite way and go from the simple form to Pennée , the upper leaves with three to five leaflets Date , ovals to lanceolate . The Petioles are slightly winged. ^[3]

The plant can flower at any time of the year, but mainly in summer and fall in temperate regions. Flowers are small CAPITULES carried by Peduncles relatively long . The heads consist of approximately four or five wide White florets (Ligules), surrounding many flagships unwavering yellow tubular which develop in barbed fruits. ^[4]

The fruits are slightly curved, rigid and rough black stems, of a tetragonal cross section, about 1 cm long, generally with two to three stiff and strongly barbed lines to their Distal extremities .

The Infrutescences form Balvs Sphericals starred about one to two centimeters in diameter. The barbed wicks of the Akens get stuck in feathers, fur, fleeing, clothes, etc. People or animals who close the plant. ^[5] [6] It is an effective means of Dispersion of the seeds by zochoria, because the fruits are transported by animals. This mechanism has helped the plant to become a harmful weed in temperate and tropical regions.