I think so. I'm better with visual aids if you feel like popping up a pic or two. I don't think that stem girth matters though. If the leaves don't give it away, the flowers are definitive.
Your plant reminds me of this strange cutting. All of the other cuttings I did are 'normal' but this one is making smaller and smaller leaves and tiny buds to go with them. Can't wait to see one open, hope they do. It's definitely S. truncata, but some kind of mutant mini one.
