Anubias, Java moss, Onion plants, amazon swords, anacharis. While the goldfish may nibble on these, they should easily outgrow what they eat.
I am only sharing what worked for Molly, and V. spiralis was one of them. Maybe if she had bigger goldfish, it would be a problem, but in her tank, they look like they are doing very well.Carlos, If I'm not mistaken only Vallisneria gigantea will work as V.spiralis can easily be uprooted and munched on.