Rangeland, along roadsides, edges of fields, burned areas, and other disturbed or mismanaged sites
Native to Europe, western Asia, and northern Africa; widespread across the United States
No listed status
This species is
to the Truckee Meadows.
Bull thistle grows as a rosette (ground‐hugging form) in the first year, and then sends up stems and flowers in the second year, growing to 6 feet tall. Flowers are pink to purple, vase‐shaped and in branched clusters at the ends of the stems. Bracts (modified leaves located under the flower petals) are spiny. Blooms from summer to fall. Leaves are lobed, hairy and rough on the upper side; soft on the underside, with a raised center vein. Lobe tips have long, stiff spines.The leaves in the ground hugging, first year rosette are fuzzy with visible bumps. Stems are spiny and winged.
Bull thistle is highly competitive and aggressive, forming dense colonies that choke out native vegetation important to wildlife and pollinators. Seeds germinate rapidly and are spread by wind. An individual plant can produce up to 100,000 seeds.
Thistles often look similar, and there are several native thistles in the Truckee Meadows area that can be confused with invasive, non-native thistles. This document can help you “know your thistles”
Bull thistle is native to Europe, western Asia, and northern Africa. It is thought to have been introduced to the eastern United States during colonial times and the western United States in the late 1800s. It is currently found in all 50 states.
Image: Franco Folini, https://www.flickr.com/photos/livenature/6031255316/, license https://creativecommons.org/licenses/by-sa/2.0/, cropped from original.
Image: NY State IPM Program at Cornell University, https://www.flickr.com/photos/99758165@N06/18218898583/, license https://creativecommons.org/licenses/by/2.0/, cropped from original.
Image: Fishermansdaughter, https://www.flickr.com/photos/fishermansdaughter/4756033464/, license https://creativecommons.org/licenses/by/2.0/, cropped from original.
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