Definately a lot of hybrid Sans out there!! Lots of variation in the species too, especially the long cultivated S. trifasciata which are probably the most common types you will find in the big box stores etc.. The various colored little birdsnest hahnis, medium futura type and many tall cultivars are all pure trifasciata selections. However there are a lot of hybrid Sans available too, especially coming out of Asian and Phillipines but even the USDA was hybridizing Sans for fiber production last century.

Sansevieria trifasciata 'Laurentii' is actually a chimera and that is the reason that you cannot start this cultivar from leaf-cuttings since the resulting plants will be all green. The yellow stripes are the chimera portion of the leaf and and a new plant never forms from this chimera portion of the plant leaf.