I think this is what you're looking for: Cardiocrinum giganteum. Haven't grown it yet, want to. Hope this at least gets you more search results and such.

I don't know how new they are......I've had for years an orienpet hybrid that easily reached 6-7' and had dozens of flowers. No longer remember the name now but it came from one of my local dealers, was a very large bulb and IIRC, had a pretty good price tag, too :-) But that was back when I was buying lily bulbs by the cartload - I restrain myself now. Trumpets in my garden regularly reach 5-6'.

With specific selection and with large, very mature bulbs, it is not at all uncommon for some lilies to achieve significant height. But I'd not call them trees........that is just a marketing ploy :-) And unless they were something really unique in the way of flowers and I could see and judge the size of the bulb myself, I doubt I would be very tempted to pay a premium price for them.

Cardiocrinum gigantium has the potential to get much larger - 10-12' is not unusual. But it is not a true lily and has very specific growing requirements and will be limited in its application in most parts of the US. It is also monocarpic......it takes around 5-7 years before it reaches flowering size and after flowering, it dies. It does produce offsets but again, they will take time to reach a blooming size.

I purchased a variety of "tree lilies" a couple of years ago and I love them. I have several colors with different markings from other lilies. But I did figure out that they are Orienpet lilies, not some new species. They have been bred so they have such lovely colors and markings and gorgeous scent, plus they bloom a little later than the Orientals and seem to last a very long time. I'm buying more this year, I love them so much.

This is just a marketing ploy. As was mentioned these are simply OT lilies, Oriental crossed with trumpet lilies, also known as Orienpets. There is no such thing as a tree lily.

Chris

A particular vendor calls them "Lily trees". No reputable lily vendor calls them that.