Sacred Datura Datura wrightii
These beautiful flowers open at night and stay open until they are spent. They have a very sweet fragrance and are related to tomatoes and peppers.
Other beautiful flowers you might find in the garden include:
Daylily Hemerocallis 'Ruffled Apricot'
Daylily Hemerocallis x 'Gothic Window'
Balloon Flower Platycodon grandiflorus
Balloon Flower Platycodon grandiflorus