Morphology of leaves and stem of white-purple varieties of O. aristatus from in vitro cultures and wild type. a: white-purple stems (in vitro culture), b: white-purple stems (wild type), c: white-purple leaves (in vitro culture), d: white-purple leaves (wild type), e: white-purple varieties 5 months old (in vitro culture), f: white-purple varieties 5 months old (wild type)