Sansevieria trifasciata 'Laurentii' gelber Rand , S. trifasciata 'Robusta' Sansevieria trifasciata 'Laurentii' gelber Rand , S. trifasciata 'Robusta' oben links , S. zeylanica unten rechts, S. cylindrica 'Wild' oben Mitte ( Bogenhanf )Air cleaning plants according to NASA