I have trouble sometimes telling some collections of puberula from the involucratas and have read where some think puberula should be a subspecies. My form is pretty different from the one PDN sells, in that the foliage is fuzzy and more aromatic. I had thought this was a distinguishing feature for that collection. But PDN calls theirs El Butano, too, so I remain a little confused as to which one I really have. The tag is long lost down at the bottom of the patch and my memory isn't what it used to be.