The Virginia Dayflower is one of my favorite blue flowers in autumn. It is a perennial herbaceous plant, native to the mideastern and southeastern US. It is important to count the blue petals. The Virginia Dayflower has 3 blue petals. The Asiatic Dayflower has only 2 blue petals, plus a tiny white one. They bloom now too, often close to each other in wet soil, and are a deeper blue.