Weighing in...it certainly could be 'Triumphator'. I had 'Triumphator' on the east side of the house and it grew 5 bto 6 feet tall. I had it in the front actually, because I had planned for it to be the 3 or 4 feet it was advertised. Well, had to move that lily after two years. I see this with a lot of LO lilies, they get really tall! The stalks are thick and can take the height, which is nice, no staking
And 'Friso' (which may also really be 'Silk Road', have both, look identical, and bloom at the same time,) also has a different leaf structure. Triumphator is a better hypothetical guess than Friso. Though whoever it is, it is most certainly very pretty.
