No expert, but from others on here I've learned that many plants that were hybridized (sp?) to create unique plants only grow that way the first year and then DO revert back to the original parent plant.

I was told this when I got all excited last year about 'stealing' some seeds from a hybrid plant at my eye dr. office and was told that would probably happen.

Or something like that. I'm sure the more seasoned folk can tell you more.

The hybrids don't come true from seed. It's possible that your original plant didn't overwinter, and you have a new, self-seeded plant. Just a guess.

I really don't think this is a new seedling. For one thing, I have grown them from seeds before and purple coneflowers don't get very large the first year. This is behaving almost like a grafted plant but the top died off and the root stock is blooming. Do you know how they propagate these hybrid purple coneflowers? It is actually a very pretty flower... it is just not twilight. :)

It happened to me too, but with Tomato Soup. I overwintered it in my basement, so it did not even lose its basal leaves. These year all the big shoots are ordinary purple. To top this all, some flowers are distorted and some have quilled petals(as in Big Sky series). You can't really imagine my surprise.

Here are my pictures what happened to Tomato Soup.

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As you can see, the form of the flower (except distortion) and the habit of the plant is like Tomato Soup.