Aster is a genus of flowering plants in the family Asteraceae. Its circumscription has been narrowed, and it now encompasses around 180 species, all but one of which are restricted to Eurasia; many species formerly in Aster are now in other genera of the tribe Astereae.
Eurybia divaricata (formerly Aster divaricatus), commonly known as the white wood aster, is an herbaceous plant native to eastern North America. It occurs in the eastern United States, primarily in the Appalachian mountains, though it is also present in southeastern Canada, but only in about 25 populations in the provinces of Ontario and Quebec. In the U.S. it is abundant and common, but in Canada it is considered threatened due to its restricted distribution. It can be found in dry open woods as well as along wood-edges and clearings. The species is distinguished by its flower heads that have yellow centers and white rays that are arranged in flat-topped corymbiform arrays, emerging in the late summer through fall. Other distinguishing characteristics include its serpentine stems and sharply serrated narrow heart-shaped leaves. It is very similar to and often confused with E. chlorolepis, E. schreberi and Symphyotrichum cordifolium, though E. schreberi differs in having wider leaves with more teeth, while E. chlorolepis has more rays, longer involucres, and only occurs in the southern U.S. from Virginia to Georgia. The white wood aster is sometimes used in cultivation in both North America and Europe due to it being quite tough and for its showy flowers.