Don't know. But I did plant a new liatris plant this spring. 4 stems are lav, one is white, Go figure.
jan

I have a coneflower plant and half the flowers are purple and half white (and yes, I'm sure it's just one plant!).

...cue the Twilight Zone music... lol

Liatris sometimes starts out white then shifts to a pale purple. I had this happen last year to my clump out front. It took several weeks and was quite a surprise, but did in fact shift. None of it has done so in the same clump this year - must be the weather - it's all opened it's proper purple. Perhaps the buds are opening before the pigments are properly up?

-Marie

Here's what I've heard can happen. Taking liatris as an example, the native color is purple. It's been bred so some cultivars are white. This is basically a mutation of sorts. In some cases it's not 100% stable so stress can cause it to revert.

But I don't have an explanation for a purple one turning white.

I wish my purple would turn white!

Mine are blooming white this year. Last year they were bright magenta-purple. Must be the weather? (I was jsut so happy that they wintered over. Before, they always died on me.)