This is Hymenocallis narcissiflora, also called Peruvian Daffodil, Spider Flower, and Basket Lily. I bought two of these bulbs last spring at Lowes and am happy to see that it is multiplying. (Three sprouted this spring!)
It's normally hardy in zones 8 - 10, but I'm able to keep this one in zone 7 thanks to an ample amount of Nature-provided protective mulch in the form of leaves from my really HUGE pecan tree. (LOL Really a lot of leaves - usually about six inches of them that I leave until after the last frost.) It blooms in mid summer and grows to between two and three feet tall. I think I snapped this pic in mid-to-late May. The blooms are really large (about four inches) and very fragrant.
On the trellis to the left is Carolina jasmine. The yellow flowers in the background are Rudbeckia hirta Indian Summer transplanted from my mom's garden. I've since realized that they really don't like my heavy soil. LOL They're much happier at Mom's where she has a higher sand content.