I always check Liberty Hyde Bailey's, Manual of Cultivated Plants
(Macmillan).
He says Hypericum has "obscure meaning."

You can also try searching for: hypericum etymology

The following webpage favors the first derivation of "above a picture"
and says Linneaus favored that meaning.
http://www.healthy.net/scr/article.asp?ID=915

David R. Hershey