Nodding thistle

Family: Asteraceae
Scientific name: Carduus nutans subsp. nutans
Description: Plant Form biennial herb to 70 cm tall; stems with spiny wings. Leaves near base to 250 x 100 mm, dissected, spiny; stem leaves to 100 mm long, stem-clasping. Flowerheads purple, often nodding, with involucral bracts dark purplish, spine-tipped, often somewhat cobwebby. Fruits 4-5 mm long, with pappus (parachuting hairs) of unequal bristles to 20 mm long.

Example images for this weed