I have this listed as Perurian davodil
I am not very sure

My best guess is hymenocallis.

It looks like Hymenocallis 'Tropical Giant', a large one with very broad leaves. Do three of the six tepals recurve down more than the others? It has a 'sister' which doesn't have this peculiarity.

http://www.pacificbulbsociety....

I managed to get one of these but it's barely growing even keeping it in a greenhouse over summer! It's one of the more desirable hard to get ones.

Hymenocallis, several species are native the Gulf Coast States.
http://www.wildflower.org/plan...

Thanks all
Will have to wait till it blooms again to try and figure which Hym.