Stinking Willie

Common names include ragwort, common ragwort, tansy ragwort, benweed, St. James-wort, ragweed, stinking nanny/ninny/willy, staggerwort, dog standard, cankerwort, stammerwort, mare's fart and cushag.

 

In the western US it is generally known as tansy ragwort, or tansy, though its resemblance to the true tansy is superficial.

 

Thanks to Wikipedia for the info!

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