As a result of these various posts, I am tentatively thinking my trumpet lily may be 'White Henryi'. I already have an order with the Lily Garden for 5 OT lilies for this fall. I just emailed a request for 'White Henryi' to be added to my order. So next year I will be able to compare the flowers of my 20 year old lily with a new "definitely" White Henryi! That is, if it is still in stock this close to shipping season.
This is the area where I have 7 OT lilies, planted in fall 2015, and just past full bloom right now. So I will have 13 tall lilies there for future years! If you click on the photo it looks a lot better enlarged (a horizontal view with the lilies along the 40 ft. length of the branch which broke off my big maple tree in june, 2015. A work in progress with 200 red tulips, 7 newly planted peonies and 17 late season daylilies, plus the 7 OT lilies now in bloom... all an effort to have something in bloom all growing season!
Also in the photo, my prized decrepit toolshed which I just painted red to match its rusty tin roof!