The genus Aster (sunflower family - Asteraceae) is now generally restricted to the Old World species. The other species have now been reclassified as Afroaster, Almutaster, Canadanthus, Doellingeria, Eucephalus, Eurybia, Ionactis, Oligoneuron, Oreostemma, Sericocarpus and Symphyotrichum.
Aster synonyms
References