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Scotch thistle

Onopordum acanthium


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Family

Asteraceae

Description

Scotch thistle (Onopordum acanthium) is a biennial or short-lived perennial native to Europe and western Asia, recognized for its towering height (often exceeding 6 feet), silvery spiny leaves, and globular lavender-purple flower heads. It forms a large basal rosette in its first year and sends up a branched flowering stalk in the second. Historically used as a symbol of Scottish heritage, it now naturalizes widely across disturbed sites and pastures in parts of North America, where it is considered invasive in some western states. Despite its formidable spines, it draws a variety of pollinators, particularly native bees and butterflies.

Though hardy and dramatic in appearance, O. acanthium spreads readily by seed and is best managed in cultivated settings to prevent escape. It prefers full sun and well-drained soils but tolerates drought, poor fertility, and occasional disturbance, making it suited to dry meadows and wild gardens when thoughtfully placed.

Bloom Time

July to September

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