Q.Water Lily Plant In Pot
A black thick root comes out of the plant and a new one grows at the end, reducing the flowering capability of the existing. Shall I cut this off? Will it hurt the plant?

Certified GKH Gardening Expert
It won't harm the top, and if the plant is well cared for, it won't take much from the parent. You can wait until it grows roots, and then cut it to produce a new plant, if you would like!
https://www.gardeningknowhow.com/ornamental/water-plants/water-lily/growing-water-lilies.htm
https://www.gardeningknowhow.com/ornamental/water-plants/water-lily