Commonly known as New England aster,[4] hairy Michaelmas-daisy,[5] or Michaelmas daisy,[6] it is a perennial, herbaceous plant usually between 30 and 120 centimeters (1 and 4 feet) tall and 60 to 90 cm (2 to 3 ft) wide.

The seeds and nectar of this mostly conservationally secure species, which blooms August to November, are important to a wide variety of animals, including birds, bees, and butterflies.

It has been introduced to Europe, Central Asia, Hispaniola, New Zealand, and some western states and provinces of North America.

[9] These occur at the base, on stems, and on the flower head branches which all have generally the same lanceolate appearance regardless of their location on the plant.

[3] Symphyotrichum novae-angliae is a late-summer and fall blooming perennial with flower heads opening as early as August in some locations and as late as November in others.

Several varieties and forms have been described, differing in flower color, but these generally are not recognized and are considered taxonomic synonyms of the species.

Named Symphyotrichum × amethystinum (amethyst aster),[21] the hybrid is intermediate between the parent species in most respects.

[23] The species' former genus, Aster, comes from the Ancient Greek word ἀστήρ (astḗr), meaning "star", referring to the shape of the flower.

The word "aster" was used to describe a star-like flower as early as 1542 in De historia stirpium commentarii insignes, a book by the German physician and botanist Leonhart Fuchs.

An old common name for Astereae species using the suffix "-wort" is "starwort", also spelled "star-wort" or "star wort".

An early use of this name can be found in the same work by Fuchs as Sternkraut, translated from German literally as "star herb" (Stern Kraut).

[25] New England aster is native to most of the central and northeastern United States and southeastern Canada, from Manitoba south to Louisiana and east to Maine.

[26] Due to widespread cultivation, introduced populations are present elsewhere in North America including in Montana, Oregon, Utah, Washington, and Wyoming.

[3] It was found in Nova Scotia and considered a possible escapee from cultivation,[27] but as of July 2021[update], it is categorized as native there.

It is considered ephemeral in British Columbia,[6] with recorded sightings in 1993 and 1994 near Vancouver, probably originating from railroad cars and garden waste.

[31] S. novae-angliae is found in a wide variety of open, typically moist habitats, including meadows, prairies, marshes, fens, forest edges, and disturbed anthropogenic sites, such as roadsides and former agricultural fields.

[3][32] In its native habitat, it grows primarily in moist calcareous soils,[33] favoring more marshy-wet sites in the western-most of its range.

[35] For example, in one northern location, the Niagara Peninsula in southern Ontario, it was found to grow in dry and sandy soils.

[33] Symphyotrichum novae-angliae has coefficients of conservatism (C-values) in the Floristic Quality Assessment (FQA) that range from 0 to 8 depending on evaluation region.

[36] The higher the C-value, the lower tolerance the species has for disturbance and the greater the likelihood that it is growing in a presettlement natural community.

[37] In the Dakotas, for example, S. novae-angliae has a C-value of 8, meaning its populations there are found in high-quality remnant natural areas with little environmental degradation but can tolerate some periodic disturbance.

[38] In contrast, for the Atlantic coastal pine barrens of Massachusetts, New York, and Rhode Island, it has been given a C-value of 1, meaning its presence in locations of that ecoregion provides little or no confidence of a remnant habitat.

[26] Further, a wide variety of generalist nectar-feeding insects visit the plant, including butterflies, moths, ants, flies, and bees.

[32] Fungi known to affect the species include the mildews Basidiophora entospora (downy) and Erysiphe cichoracearum (powdery), and a black knot fungus Gibberidea heliopsidis.

[54] The S. novae-angliae cultivars grow to between 90 and 200 centimeters (3 and 6+1⁄2 feet) in height, with the notable exception of 'Purple Dome', at 45 cm (1+1⁄2 ft).