This one has been in the lower border all the time I've worked there (ie. I didn't plant it) which is more than 6 years. I must check the records to look for likely candidates. It's a small herbaceous species - no woody parts at all and running a bit underground and the flowering stems have never got to more than 12ins high. The foliage is actually pretty sage-like - not more than 2ins long. I'll give it a sniff and report back. The flowers are about a half inch long.