I did not know the name of this wildflower--another from the aster family. Erigeron annus can be distinguished from Common Fleabane (Erigeron philadelphicus) because the leaves of the Daisy Fleabane do not wrap around the stem of the plant (the botanical term is "clasping"), whereas the leaves of the Common Fleabane do. The name fleabane hails from the days when the smoke from the burning of this plant was thought to keep fleas and other insects at bay. The flowers of Common Fleabane close at night, but I could not confirm (without running across the street in my pjs and getting eaten alive by repellent-resistant mosquitos) if Daisy Fleabane does so as well.
Learn to identify one hundred species of flora within walking distance of your home! scsours began this challenge in July of 2008, and I was eager to hop on the bandwagon about a month later. I've remembered much and learned even more. It's been a fun but slow process. Spring has finally arrived here in Massachusetts, and I will hopefully be posting often soon.