Interesting to see how your Gladiolus uysiae bulb spreads. My G. alatus spreads exactly the same way. I don't know whether those underground runners can rightlfully be called rhizomes, but they can be maddening. If I plant the bulbs in the center of the pot, the runners will run to the edges of the pot and it is there that the new plants will grow. I once tried to fool them by planting the bulbs near the edge of the pot, hoping the new plants would arise near the center. It didn't fool them: they came up at the edge anyway. David E. Redwood City (SF Peninsula) CA