| Symphyotrichum genus | |
|---|---|
| |
| Some Symphyotrichum species left–right, top–bottom are shown: S. carnerosanum, S. chilense, S. adnatum, S. lateriflorum, S. concolor, S. ericoides, S. defoliatum, S. ciliatum, S. novae-angliae. | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Subfamily: | Asteroideae |
| Tribe: | Astereae |
| Subtribe: | Symphyotrichinae |
| Genus: | Symphyotrichum Nees |
Symphyotrichum is a genus of flowering plants in the tribe Astereae which includes the commonly cultivated New York aster (S. novi-belgii) and New England aster (S. novae-angliae). Its species are widespread in the Americas, including as far north as subarctic North America to as far south as Chile, Argentina, and the Falkland Islands. One species has a native range extending into eastern Eurasia.
Most of the species in the genus are perennials. The flower heads have white, pink, purple, or blue ray florets surrounding white to yellow disk florets. The disk floret corollas become pink, purple, or brown after pollination. The three species in section Conyzopsis have reduced or absent ray florets.
Symphyotrichum is the type genus of subtribe Symphyotrichinae. There are 98 species in the genus, some with varieties, and thirteen named hybrids. The genus is split into five subgenera: Chapmaniana, Astropolium, Virgulus, Ascendentes, and Symphyotrichum. Most of the species had been classified within the genus Aster until it was confirmed to be polyphyletic. The American asters now are separated into monophyletic genera based on multiple phylogenetic studies.