Thanks I will. This is certainly a surprise. My vals, wisteria, and ferns propagate all the time, but I've never had a sword do that.
I've had this sword for a few years. The tank may have extra phosphates. This is a 29 gallon my son and I set up for his science class. It gets about 3-4 hours of direct sunlight every day. I suspect that is why the plants do so well in there. It may also be the reason it's flowering under water.