Symphyotrichum


Symphyotrichum is a genus of about 90 species of herbaceous annual and perennial plants in the composite family that were formerly treated within the genus Aster. The majority are endemic to North America, but several species also occur in the West Indies, Central and South America, as well as in eastern Eurasia. Many species have been introduced to Europe as garden specimens, most notably the New England aster and the New York aster.

Name

The botanist Christian Gottfried Daniel Nees von Esenbeck established this genus in 1833 because he felt that a plant he examined, now thought to be a cultivated variety of New York aster, was sufficiently distinct from the rest of the genus Aster to warrant its own genus. He emphasized the uniqueness of this plant in having its pappus hairs arranged in a coherent, basal ring. This structure is the basis for the scientific name of this genus, which derives from Ancient Greek σύμφυσις "growing together" and θρίξ "hair". Unfortunately, this characteristic ring is not generally shared by most New York aster pappi, nor is it characteristic of any other plants included in the modern concept of Symphyotrichum. According to the rules of the ICN, however, the timing of this genus's establishment gives it precedence over other names.
This genus was resurrected in 1994 by Guy Nesom to group together species formerly included in Aster in order to make modern genera monophyletic.

Species

There are about 90 species, including: