I think this is a particularly good form of Salvia mexicana. This is difficult to grow in the UK as it is normally ready to flower just as the first frost occurs, and is too tall to move into a small greenhouse.
It sets seed pretty well, unless bumblebees get to the flowers. It should come true from seed, unless there are other mexicana forms around. It comes from the state of Hidalgo, between Jacala and Zimapan. The form La Placita was collected just a few miles down off the old PanAmerican Highway