@ Dolly da Gucci,
This is a fascinating plant behavior that but I am afraid I do not have an answer to your question.
The little I know is that mimicry is a behavior plants adapt in order to facilitate pollination. I would really like to know the molecular basis of it too!
The other side of the coin is insect mimicry- the insects that camouflage to look like plants-apparently a very old plant behavior that has been seen even in fossils.