Erigeron annuus (Eastern Daisy Fleabane)

Native to central and eastern Canada and the United States, this annual herb grows in open, disturbed ground such as roadsides, fields and waste areas. Its upright stems have spreading hairs and bear toothed or nearly smooth-edged leaves. Loose, branched clusters carry numerous small flower heads with white rays surrounding yellow centers. The lower leaves often wither before flowering. In North America, blooming generally occurs from June through August and can continue into autumn. The species has been introduced widely beyond its native range. Photographed in Colombia.