Bidens pilosa

Scientific Name Bidens pilosa
Common Names English: Common blackjack, Spanish needle; German: Behaarter Zweizahn; French: Bident poilu
Description Annual, seed-propagated weed, forms a dense ground cover.

Descriptions

Characteristic Features

Ray florets absent or 4-7 per head, rays 2-8 mm (0.079 - 0.31 inch) long.

Cotyledons

Lanceolate, striped lengthwise, with reddish hypocotyl.

Stems

Erect, ramified, square, hairless, up to 120 cm (47.24 inch) high.

Leaves

Petiolate, with 1-2 pairs of petiolate pinnae and a large terminal pinna.

Propagatio Organs

Flowers

Flower heads longer than wide, with yellow disk florets and white ray florets.

Flowering Period

Summer.

Fruit

Achenes dark brown or black, straight, wingless, 8-16 mm (0.31 - 0.63 inch) long, setose.

Seeds

Germination in spring.

Viability Of Seeds

3-5 years.

Propagation

By seed. Seeds attach to clothing or animal's fur or feathers. A. patula is also dispersed by water. Ca. 3,000-6,000 seeds/plant.

Occurrence

Habitat

Pastures, plantations, along roadsides and on wasteland.

Soil

Moist, nutrient-rich, warm regions.

Agricultural Importance

Major weed in vegetables, forms a dense ground cover that prevents regeneration of other species.

Related Crops

Choose directly from Category

Pests

Pests

Search directly for a particular pest

Diseases

Diseases

Search directly for a particular disease

Weeds

Weeds

Search directly for a particular weed

Choose by Crop