One of the sights that most impressed me on our recent trip was the bright orange day-lilies blooming wild in the ditches from Kentucky to Virginia. My experience with day-lilies told me that they are just that - the blossoms only open for a day, so I was amazed that there were so many in bloom.
A bit of research on line tells me that these are Hemerocallis fulva, among the first day-lilies imported from China 100 years ago and that they are particularly hardy. If you look carefully at the picture above, you will first notice the flowers in full bloom, but then you'll see buds that have not yet opened, and the folded petals of flowers that bloomed yesterday. They are prolific bloomers, which explains how a day-lily could seem to be in bloom for weeks or months.
I also learned that they are edible. Chinese eat the bulbs, while Americans are said to prefer eating the blossoms.