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Bull Thistle (Flowerhead)

Photo of a bull thistle flowerhead.

The flowerheads of bull thistle are reddish purple to purple, with a prominent involucre (the flowerhead base, covered by leaflike bracts), which is covered with a fine, cobweb-like silk. Spiny bracts grow right up to the flowerheads.

Shortened URL
http://mdc.mo.gov/node/28708