In message .com, La
Puce writes

Nick Maclaren wrote:
It definitely DOES grow from seed, as it has been a casual in my
garden several times!

Upon checking, that seems to be the only fully hardy, creeping
Hypericum. There are lots of other hardy ones, but all seem to
be bushy.

Would that be St John's Wort?!

H. calycinum is Rose of Sharon; several other shrubby species are
Tutsans. It is not clear to me that the sobriquet St. John's Wort is
correctly applied to any of the shrubby (as opposed to herbaceous) forms
of Hypericum.
--
Stewart Robert Hinsley