I'd bet that the green part is the root stock that a variegated cultivar had been grafted to, and the graft ~died back~ and the green took over, but the graft has been resurrected by new conditions (do you live in a church?). OP could wash the roots and see if a section of the roots connected to the white parts could be cut off, leaving enough roots to support the green part. Caution: all white plants are parasites and perish because they can only live on the resources produced by green-leafed plants, and Just as Lady Thacher said, "Socialism works until they run out of other people's sucrose."
Plants that are variegated, that is have some white and some green (chlorophyll containing leaves) are chimeras and can further evolve in any direction, to all green, or all white, or flopped green on white or white on green, so you can't tell which way this will go.