Bull thistle.
t is a tall biennial or short-lived monocarpic thistle, forming a rosette of leaves and a taproot up to 70 cm long in the first year, and a flowering stem 1– m tall in the second (rarely third or fourth) year. The stem is winged, with numerous longitudinal spine-tipped wings along its full length. The leaves are stoutly spined, grey-green, deeply lobed; the basal leaves up to 15–25 cm long, with smaller leaves on the upper part of the flower stem; the leaf lobes are spear-shaped (from which the English name derives). The inflorescence is –5 cm diameter, pink-purple, with all the florets of similar form (no division into disc and ray florets). The seeds are 5 mm long, with a downy pappus, which assists in wind dispersal. As in other species of Cirsium (but unlike species in the related genus Carduus), the pappus hairs are feathery with fine side hairs.[1][4][5]
Size: 2520px × 3776px
Location: Fairport NY USA
Photo credit: © Peter Steiner / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: biannual, bloom, blue, bull, florets, flower, pin, prickles, prickly, purple, red, sky, spear, spines, stem, thistle, thorns, thorny, vertical, weed
