These flowers belong to a vine called a Silver Lace Vine. They're invasive and a weed actually, but they're so pretty they're a pleasure to grow and watch. Most flower nurseries sell them. My mom has them around 2 of her big windows. They're beautiful and have a sweet perfume type fragrance, very light. They can take over if they aren't properly managed, as they will choke out other vines. The flying insects love them, I could watch them all day!