It's a species of Salvia which will remain un-named in the interest of not drawing folks to this site, who might otherwise be led here by Google results (yes it's THAT species).

Two autumns ago I decided to try an experiment. I took a cutting off one of my two plants that I overwinter in a greenhouse. After rooting, I planted it amidst my bamboo plants in the tropical garden. I placed a small tomato cage around it and filled it with leaves.

The next spring I uncovered the plant and was delighted to see that it survived with a few leaves and about 5" of green stem.

Then last fall I decided to take my experiment a step further... I provided absolutely no protection and let the poor thing absorb the brunt of our fairly mild winter. Temps got down to about 30 degrees F. a half dozen nights this past winter and around January I noticed that the stem was totally brown down to the soil level.

I figured it was toast...

Periodically throughout the spring I would notice the pathetic stick still standing there between the bamboo culms and nearly clipped it off a couple of times.

But today, as I was weeding around the area, I noticed unmistakeable Salvia leaves just starting to emerge from the soil about 1/2" away from last year's stem!

As Robin mentioned in a recent thread, the plant itself is naturally leggy and not especially attractive, but the flowers are to die for.

My next attempt will be to try to get the plant in the ground to flower, rather than relying on my greenhouse plants to provide a thrill.