Peppermint China
This is a compact, well-branched  plant about 3x3'  with wiry, narrow stems.   The tiny blooms are about the size of a dime or nickel and have a  subtle striping.  It could be a good plant for pot culture and reblooms well.  I estimate the hardiness from about zone 6.  In my zone 7 garden I do not see much winter damage on it.