Picão-Preto (Bidens pilosa)

 

Inflorescence. Photo: Decius Karam - Embrapa Maize and Sorghum

     

Family: Asteraceae - Origin: Tropical America

            Morphological description: Herbaceous, erect, with size ranging between 20 and 150 cm, with reproduction by seed only. Rapid development and has high seed production, under tropical conditions, the plant can be found throughout the year.

            Distribution: It is found mainly in the tropical regions of North America and South Africa, in Brazil, is distributed throughout most of the territory, especially in agriculture production.

          Seedling: Hypocotyl cylindrical, smooth and hairless, usually with reddish pigmentation; lanceolate cotyledons, can measure up to 2 cm long epicotyl light green, ribbed, with short hair, true leaves opposite, hairless, dark green in the face ventral and light green on the dorsal.

          Leaves: petiolate, opposite the stem and branches-oval or speared, greenish, purplish tints may have; may occur Leaves simple or compound, with up to 8 cm long and 4 cm wide, leaves with serrated margins, with or without the presence of hair,

          Stem: Erect, branched, quadrangular and smooth surface, green color and may be streaked or brownish-red spots, with or without the presence of hair.

           Flowers, Chapter shaped yellow buttons surrounded by a series of white leaflets; presence of petals generally white or yellow.

          Seeds: They have variable size, color matte black, finely wrinkled and pontilhadas.Possuem two or three edges in the apical part.

          Inflorescence: Chapters alone or in combination, terminals, each supported by a stalk to 5 cm in length.

          Important: Infeesta annual crops and perenea in more than 40 countries, high infestations can cause losses up to 30% in productivity, host plant fungi, nematodes and viruses.

Source: www.embrapa.org.br