It is best to pinch off the leaves that hit the surface. If you do, you can keep it as a submerged plant, which will look better in an aquarium. If you don't, all leaves will rapidly go for the surface covering it so less light reaches the remaining submeged plants and the lilly will try to bloom if there is room in the hood for it. Depending on your lighting this may be a hazard if the lights and flower are too close.
Member AGA, HAS, NASH
110G, 10 adult discus, barebottom with plants on wood
58G, 3 adult discus, barebottom with plants on wood
59G thickly planted tanks, rummey nose tetras, kuhlies
300G goldfish pond outside