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Scotch Thistle (Onopordum acanthium) |
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Cirsium vulgare The heavily armed ridges on the stem and woolly white hair on the leaves will identify this thistle species. Bull Thistle is similar in many regards, but lacks continuous ridges of spines. Scotch Thistle has an overall gray tint to it. Bull Thistle, although the undersides of the leaves are woolly and white, is clearly green. Scotch Thistle (Onopordum acanthium) Alien: Introduced from Europe. Identification: Flower head round to globular, topped with a shaving-brush of rose to lavender elongate florets. Flower head bracts elongate, spiny, each spine tipped with yellow. Base of bracts covered with white, downy hair. Stem with ridges, each ridge armed with triangular spines. Leaves narrow at the top, but broader near the base, heavily dentate with each toothed tipped with a spine, but leaf otherwise undivided. Leaves covered with white, downy hair. Plant 2 to 4 feet in height. Distribution: Throughout most of North America, but local in distribution. Habitat: Scotch Thistle is a weedy species found in disturbed habitats such as fields, empty lots, and roadsides. Flowering period: July to September. |
Scotch Thistle (Onopordum acanthium)
Similar Species: Bull Thistle (Cirsium vulgare)
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Similar Species |
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