It's quite a tough plant, if that helps. Roots are tough too; doesn't fall apart like other aquatic plants, and much harder than the standard Val...I'll Google the spiral one, thanks!
I second the italian val suggestion. Definitely looks like a val. Any idea where it came from? Looks similar to the american val but i doubt they are selling that in scotland
update on this guys, I discovered its a type of land plant, sold as aquarium plants that tends to live for a year then die. Avoid it; I think its called Mondo Grass or something