(syn. Diplopappus Cass.
) is a genus
of flowering plants
in the family Asteraceae
. The genus once contained nearly 600 species in Eurasia and North America, but after morphologic
and molecular research on the genus during the 1990s, it was decided that the North American species are better treated in a series of other genera. After this split there are roughly 180 species within the genus, all but one being confined to Eurasia. The name Aster
comes from the Ancient Greek
, meaning "star", arriving through the Latin
with the same meaning, referring to the shape of the flower head
. Many species and a variety of hybrids and varieties are popular as garden plants because of their attractive and colourful flowers. Aster
species are used as food plants by the larvae
of a number of Lepidoptera
species - see list of Lepidoptera that feed on Aster
. Asters can grow in all hardiness zones.
The genus Aster is now generally restricted to the Old World species, with Aster amellus being the type species of the genus, as well as of the family Asteraceae. The New World species have now been reclassified in the genera Almutaster, Canadanthus, Doellingeria, Eucephalus, Eurybia, Ionactis, Oligoneuron, Oreostemma, Sericocarpus and Symphyotrichum, though all are treated within the tribe Astereae. Regardless of the taxonomic change, all are still widely referred to as "asters" in the horticultural trades. See the List of Aster synonyms for more information.
In the UK there are only two native members of the genus of which one, Goldilocks is very rare, the other being Aster tripolium, the Sea aster. Aster alpinus spp. vierhapperi is the only species native to North America.
Some common species are:
Some common North American species that have now been moved are:
The China aster is in a related genus, Callistephus.