How do these spread? I divided mine when I bought it just by slicing through the mass of roots. It was a huge plant. Miraculously it survived my clumsy attempts and is thriving in two pots. It has put off several long skinny sort of shoots with leaves coming from the ends. They have these sort of knobby "elbows". It feels like these might form roots if they weren't hanging over the edge of the pot. I wondered if I could cut these off and plant them elsewhere.