How are weeds spread?

List all the ways that seeds can be spread.

Carried by others:

- attached to fur, clothing, cars, etc.

- picked up and dropped by birds

- Children bring home "flowers" for mom, that scatter noxious weeds around the home.

Carried by wind and fire.

Seeds drop near the plant.

Brought from other countries.

Hidden in the feed brought to feed the farm animals.

Underground root systems also propagate plants (without seeds)

Bull Thistle - Asteraceae
(Sunflower Family)
Class B Weed

Bull thistle is a biennial. It takes two years or growing seasons to grow and make seeds It grows two to five feet tall in its second year. It has a long, fleshy taproot like a dandelion. Stems are very hairy and have dark purple veins. The first year’s leaves form a rosette and look like the musk thistle. Second-year leaves are double-toothed ending in a spine; are wavy; have prickles on the surface; and are hairy on the underside. Flower heads, made up of dark purple flowers, are 1.5 to 2.0 inches wide. Seeds are topped with a pappas.