Yet another flower that saves me from using colors like "hooker green" or "hot pink."
The myth of the heliotrope comes from Greece. It tells us about Klytia, an Oceanid (ocean nymph) who fell in love with Helios, the sun god. He returned her feelings for a while, but then quickly grew bored (as gods do) and moved on to another sea goddess, Leukothea. Klytia, mad with jealousy, told Leukothea's father, who took revenge on his promiscuous daughter and buried her alive (talk about blaming the other woman). Klytia probably thought that taking out the competition would get her back into Helios' bed, which was not the case (it really never is). Instead, she was all alone and abandoned, so she just sat on the sun-warmed rocks on the beach, following Helios with her eyes as he passed across the sky for several days. In the end, she transformed into a purple flower that still favors sunlit rocks, and still turns after the Sun.
In many translations of the myth, heliotrope is translated as "sunflower." This is, however, false, since ancient Greeks did not know sunflowers, which are a much later import from the Americas. Some version of the myth actually specifies the purple color of the heliotrope.
Read more about this story and the language of flowers here.